Datasets:

fayetitchenal

/

sciDCC

like 0

November 20, 2020

https://www.sciencedaily.com/releases/2020/11/201120142136.htm

Some Amazon rainforest regions more resistant to climate change than previously thought

Forests can help mitigate climate change, by taking in carbon dioxide during photosynthesis and storing it in their biomass (tree trunks, roots, etc.). In fact, forests currently take in around 25-30% of our human-generated carbon dioxide (CO

The current Earth system models used for climate predictions show that the Amazon rainforest is very sensitive to water stress. Since the air in the future is predicted to get warmer and drier with climate change, translating to increased water stress, this could have large implications not just for the forest's survival, but also for its storage of COColumbia Engineering researchers decided to investigate whether this was true, whether these forests are really as sensitive to water stress as what the models have been showing. In a study published today in The team found that, while models show that increases in air dryness greatly diminish photosynthesis rates in certain regions of the Amazon rainforest, the observational data results show the opposite: in certain very wet regions, the forests instead even increase photosynthesis rates in response to drier air."To our knowledge, this is the first basin-wide study to demonstrate how -- contrary to what models are showing -- photosynthesis is in fact increasing in some of the very wet regions of the Amazon rainforest during limited water stress," said Pierre Gentine, associate professor of earth and environmental engineering and of earth and environmental sciences and affiliated with the Earth Institute. "This increase is linked to atmospheric dryness in addition to radiation and can be largely explained by changes in the photosynthetic capacity of the canopy. As the trees become stressed, they generate more efficient leaves that can more than compensate for water stress."Gentine and his former PhD student Julia Green used data from the Intergovernmental Panel on Climate Change's Coupled Model Intercomparison Project 5 (CMIP5) models and combined them with machine learning techniques to determine what the modeled sensitivity of photosynthesis in the tropical regions of the Americas was to both soil moisture and air dryness. They then performed a similar analysis, this time using observational remote sensing data from satellites in place of the model data, to see how the observational sensitivity compared. To relate their results to smaller-scale processes that could explain them, the team then used flux tower data to understand their results at the canopy and leaf level.Earlier studies have shown that there are increases in greenness in the Amazon basin at the end of the dry season, when both the soil and air is drier, and some have linked this to increases in photosynthesis. "But before our study, it was still unclear whether these results translated to an effect over a larger region, and they had never been connected to air dryness in addition to light," Green, who is now a postdoctoral research associate at Le Laboratoire des Sciences du Climat et de l'Environnement in France, explained. "Our results mean that the current models are overestimating carbon losses in the Amazon rainforest due to climate change. Thus, in this particular region, these forests may in fact be able to sustain photosynthesis rates, or even increase it, with some warming and drying in the future."Gentine and Green note, however, that this sensitivity was determined using only existing data and, if dryness levels were to increase to levels that are not currently being observed, this could in fact change. Indeed, the researchers found a tipping point for the most severe dryness stress episodes where the forest could not maintain its level of photosynthesis. So, say Gentine and Green, "our findings are certainly not an excuse to not reduce our carbon emissions."Gentine and Green are continuing to look at themes related to vegetation water stress in the tropics. Green is currently focusing on developing a water stress indicator using remote sensing data (a dataset that can be used to identify when a forest is under stressful conditions), quantifying the effects of water stress on plant carbon uptake, and relating them to ecosystem traits."So much of the scientific research coming out these days is that with climate change, our current ecosystems might not be able to survive, potentially leading to the acceleration of global warming due to feedbacks," Gentine added. "It was nice to see that maybe some of our estimates of approaching mortality in the Amazon rainforest may not be quite as dire as we previously thought."

Pollution

November 20, 2020

https://www.sciencedaily.com/releases/2020/11/201120113920.htm

There are microplastics near the top of Mount Everest too

Researchers analyzing snow and stream samples from the National Geographic and Rolex Perpetual Planet Everest Expedition have found evidence of microplastic pollution on Mount Everest. While the highest concentrations of microplastics were around Base Camp where hikers and trekkers spend the most time, the team also found microplastics as high up as 8,440 meters above sea level, just below the summit. The findings appear November 20 in the journal

"Mount Everest has been described as 'the world's highest junkyard,'" says first author Imogen Napper, a National Geographic Explorer and scientist based at the University of Plymouth who is described by her colleagues as a "plastic detective." "Microplastics haven't been studied on the mountain before, but they're generally just as persistent and typically more difficult to remove than larger items of debris."Microplastics -- tiny particles of plastic that come from the slow breakdown of larger litter -- pose a huge ecological threat because they are easily consumed by animals and are so small that they are difficult to clean up. Microplastics are common in the ocean, but are not as carefully studied on land, especially remote mountaintops."I didn't know what to expect in terms of results, but it really surprised me to find microplastics in every single snow sample I analyzed. Mount Everest is somewhere I have always considered remote and pristine. To know we are polluting near the top of the tallest mountain is a real eye-opener."While some members of the research team climbed the mountain collecting samples during the Everest expedition in the spring of 2019, much of the work was done in a lab many miles away, where Napper and her team analyzed the samples. "The closest I got to Mount Everest was in my lab at University of Plymouth in the UK," Napper jokes. She wanted to determine not only whether there was plastic on the mountain, but what type of plastic was there. This is an important step in figuring out where the pollution originated."The samples showed significant quantities of polyester, acrylic, nylon, and polypropylene fibers," says Napper. "Those materials are increasingly being used to make the high-performance outdoor clothing climbers use as well as tents and climbing ropes, so we highly suspect that these types of items are the major source of pollution rather than things like food and drink containers."While this study clearly demonstrated the presence of microplastics on Mount Everest, the best way to clean this pollution remains to be seen."Currently, environmental efforts tend to focus on reducing, reusing, and recycling larger items of waste. This is important, but we also need to start focusing on deeper technological solutions that focus on microplastics, like changing fabric design and incorporating natural fibers instead of plastic when possible," she says.The researchers also hope that their work will help clarify the extent to which plastic pollution jeopardizes all environments, not just the ocean."These are the highest microplastics discovered so far," says Napper. "While it sounds exciting, it means that microplastics have been discovered from the depths of the ocean all the way to the highest mountain on Earth. With microplastics so ubiquitous in our environment, it's time to focus on informing appropriate environmental solutions. We need to protect and care for our planet."This work was supported by the National Geographic Society and Rolex.

Pollution

November 18, 2020

https://www.sciencedaily.com/releases/2020/11/201118161133.htm

Does air pollution increase women's risk of dementia?

Older women who live in locations with higher levels of air pollution may have more brain shrinkage, the kind seen in Alzheimer's disease, than women who live in locations with lower levels, according to a new study published in the November 18, 2020, online issue of

Fine particle pollution consists of microscopic particles of chemicals, smoke, dust and other pollutants suspended in the air. They are no larger than 2.5 micrometers, 30 times smaller than the width of a human hair."Smaller brain volume is a known risk factor for dementia and Alzheimer's disease, but whether air pollution alters brain structure is still being researched," said study author Diana Younan, Ph.D., of the University of Southern California in Los Angeles. "Our study found that women in their 70s and 80s who were exposed to the higher levels of air pollution had an increased risk of brain changes linked to Alzheimer's disease over five years. Our research suggests these toxins may disrupt brain structure or connections in the brain's nerve cell network, contributing to the progression toward the disease."The study involved 712 women with an average age of 78 who did not have dementia at the start of the study. Participants provided health histories as well as information on race/ethnicity, education, employment, alcohol use, smoking and physical activity. All women received MRI brain scans at the start of the study and five years later.Researchers used the residential addresses of each participant to determine their average exposures to air pollution in the three years before the first MRI scan. They then divided participants into four equal groups. The lowest group was exposed to an average of 7 to 10 micrograms of fine particle pollution per cubic meter of air (μg/mResearchers used a machine learning tool to measure signs of Alzheimer's disease in the brain, a tool that had been trained to identify patterns of brain shrinkage specific to an increased risk of Alzheimer's disease by reading the brain scans of people with the disease.Participants' MRI brain scans at the start of the study and five years later were assigned scores based on how similar they were to Alzheimer's disease patterns identified by the machine learning tool, specifically brain changes in regions found to be vulnerable to Alzheimer's disease. Scores ranged from zero to one, with higher scores showing more brain changes. Overall, the women's scores changed from 0.28 at the start of the study to 0.44 five years later.For each 3 μg/m"Our findings have important public health implications, because not only did we find brain shrinkage in women exposed to higher levels of air pollution, we also found it in women exposed to air pollution levels lower than those the EPA considers safe," said Younan. "While more research is needed, federal efforts to tighten air pollution exposure standards in the future may help reduce the risk of Alzheimer's disease in our older populations."Limitations of the study include that it only looked at the brains of older women, so results may not be the same for men or younger women. It also examined only regional fine particle pollution, not other sources of pollution such as traffic emissions. Researchers were also not able to estimate participants' exposure to fine particle pollution in middle-age and young adulthood due to nationwide data not being available for those years.

Pollution

November 18, 2020

https://www.sciencedaily.com/releases/2020/11/201118141840.htm

More children and youth drowning as warming temperatures create unstable lake ice

As winters become milder and lake ice less stable, more children and young adults are falling through the ice and fatally drowning, say York University researchers.

A new study, which looked at 4,000 drownings in 10 countries, including Canada, Russia, Finland, Germany, Sweden, and the United States, found warming winter air temperatures were a good predictor of the number of drownings. The research examined several decades of data, including 30 years worth for each province and territory in Canada.For some countries, the number of winter drownings through ice represented 15 to 50 per cent of the total annual number of drownings. Canada had the highest number of winter drownings and the territories, where people use frozen lakes more for their livelihood, such as hunting and fishing, had the highest number of drownings per capita in all of the regions analyzed in 10 countries."The time when the risk of drowning is greatest is at the beginning and the end of winter, which also corresponds to the weakest ice, when it is less stable and less thick," says lead researcher Associate Professor Sapna Sharma of the Faculty of Science, who worked with Postdoctoral Fellows Kevin Blagrave and Simon Watson, former PhD student Tessa Clemens, and an international group of scientists."In this study, we also looked at who was drowning, when, and what kind of activities they were doing at the time," says Sharma. "Almost 50 per cent of drowning victims are children less than nine years old playing on the ice, while the majority of victims drowning while in vehicles, such as snowmobiles, are young adults less than 24 years old."The complex nature of changing winters -- warming temperatures, rain on snow, and freeze-thaw events -- is destabilizing the ice on freshwater lakes and rivers in countries across the Northern Hemisphere.When winter air temperatures reached between -10 C and -5 C, drownings rose substantially. Once winter air temperatures closed in on 0 C, the number of drowning was up to five times higher than usual. Once air temperatures reached 0 C or higher, the number of drownings fell drastically, likely because the ice was visibly unsafe or non-existent.The researchers gathered drowning records from coroners offices, police stations and lifesaving societies around the world, including the Lifesaving Society Canada. They also collected temperature and precipitation data for each month and area for each drowning using the data from the University of East Anglia's Climatic Research Unit and collected population data from across Canada, Estonia, Germany, Latvia, Finland, Russia and Sweden, for regions of Italy and Japan, and from 14 states in the U.S."Because we also examine trends in lake ice over hundreds of years, we know that ice on is much later in the season and ice off is much earlier. We are seeing these trends in lakes and rivers across the Northern Hemisphere and we found that the highest number of drowning events correspond to these times of ice-off and ice-on," says Sharma. "Lake ice is important as we have strong traditions for going out on the ice to skate or ice fish, and for some, it's important for survival, such as through the construction of ice roads in northern communities that are the only way to get resources in the winter."The researchers found, however, that in those countries that have strong regulations about who can go on the ice, when, and for what activity, such as Italy and Germany, they have a low incidence of winter drownings. Sharma suggests incorporating winter ice safety in swimming lessons for children."The climate is changing and it's affecting when you can be on the ice safely. Individuals need to take that into account, especially this winter when more individuals will be out enjoying winter ice activities," says Sharma. "Times have changed, and climate has changed. Winters are among the fastest warming season, especially in Northern countries, and we're seeing the impacts of that on our lakes, and it's also contributing to tragedies each winter."

Pollution

November 18, 2020

https://www.sciencedaily.com/releases/2020/11/201118141650.htm

Which particulate air pollution poses the greatest health risk?

Researchers at the Paul Scherrer Institute PSI, together with colleagues from several other European institutions, have investigated whether particulate matter from certain sources can be especially harmful to human health. They found evidence that the amount of particulate matter alone is not the greatest health risk. Rather, it could be the so-called oxidative potential that makes particulate pollution so harmful. They are publishing their results today in the scientific journal

Particulate matter is one of the greatest health risks stemming from air pollution and, according to several studies, it is responsible for several million deaths each year. This means that poor air quality and particulate matter are among the five most important health risk factors, alongside high blood pressure, smoking, diabetes, and obesity. What makes particulate pollution so dangerous, however, is not yet precisely known. Together with an international collaborative team, researchers at the Paul Scherrer Institute PSI have now found out that the amount of particulate pollution is not the only decisive factor when it comes to health risks."In this study we were primarily interested in two points," says Kaspar Dällenbach from the gas-phase and aerosol chemistry research group at PSI. "First, which sources in Europe are responsible for the so-called oxidative potential of particulate matter (also known as aerosols) and, second, whether the health risk from this particulate matter is caused by its oxidative potential."Here the term "oxidative potential" refers to the ability of particulate matter to reduce the amount of antioxidants, which can lead to damage in cells and tissues of the human body. In a first step, the researchers exposed cells from the human airways, so-called bronchial epithelial cells, to particulate samples and tested their biological reaction. When these cells are under stress, they give off a signalling substance for the immune system, which initiates inflammatory reactions in the body. The researchers were able to show that particulate matter with an elevated oxidative potential intensifies the cells' inflammatory reaction. This suggests that the oxidative potential determines how harmful the particulate matter is. The causal connection between elevated oxidative potential and a danger to health still has not been definitely established, according to Dällenbach. "But the study is another clear indication that this connection actually does exist."A partner study led by the University of Bern showed that the cells of patients who suffer from a special pre-existing illness, cystic fibrosis, exhibit a weakened defense against particulate matter. While in healthy cells an antioxidant defense mechanism was able to stop the progression of the inflammatory reaction, the defense capacity in sick cells was insufficient. This led to increased cell mortality.In addition, the researchers collected particulate samples at various locations in Switzerland. Using a mass spectrometry technique developed at PSI, they analysed the composition of the particulate matter. The chemical profile obtained in this way for each particulate sample indicates the sources from which it originates. Furthermore, colleagues in Grenoble determined the oxidative potential of the same samples in order to get an indication of the danger to human health. With the help of detailed analyses and statistical methods, the researchers then determined the oxidative potential for all relevant emission sources. On the basis of these experimental data, they used a computer model to calculate the locations in Europe with the highest oxidative potential due to particulate matter throughout the year, and they identified mainly metropolitan areas such as the French capital Paris and the Po Valley in northern Italy as critical regions."Our results show that the oxidative potential of particulate matter and the amount of particulate matter are not determined by the same sources," Dällenbach sums up. The largest portion of particulate matter consists of mineral dust and so-called secondary inorganic aerosols, such as ammonium nitrate and sulphate. The oxidative potential of particulate matter, on the other hand, is primarily determined by so-called anthropogenic secondary organic aerosols, which come mainly from wood combustion, and by metal emissions from brake and tire wear in road traffic. The researchers found not only that the population in urban areas is exposed to a higher amount of particulate matter, but also that this particulate matter in these regions has a higher oxidative potential and is therefore more harmful to health than particulate pollution in rural areas. "Our results show that regulating the amount of particulates alone might not be effective," says Dällenbach. In addition, the study by the University of Bern suggests that population groups with pre-existing illnesses could especially benefit from appropriate measures to reduce particulate matter pollution.

Pollution

November 18, 2020

https://www.sciencedaily.com/releases/2020/11/201118141648.htm

Trees and green roofs can help reduce the urban heat island effect

Air pollution experts from the University of Surrey have found that green infrastructure (GI), such as trees, can help reduce temperatures in many of Europe's cities and towns.

An urban heat island is an urban area that is significantly warmer than its surrounding rural areas. The temperature difference is typically larger at night than during the day.With the UK government pledging to build 300,000 new homes every year, it is feared that many of the country's towns and cities will experience an increase in temperature brought about by more vehicles and building activity.In a paper published by The study focused on simulating temperature increases in the town of Guildford, UK, under different GI cover (trees, grassland and green roofs). The team adopted widely-used computer modelling systems that found that 78 per cent of Guildford was covered by grassland and trees.The research team set out to investigate five scenarios:The GCARE team found that trees are the most effective form of GI and the results showed that Guildford would be 0.128oC cooler if trees replaced all forms of GI in the town.The team also found that trees are the best solution for the reduction in temperature spikes because they can better shade surfaces and influence aerodynamic mixing of air in the atmosphere caused by enhanced turbulence.Professor Prashant Kumar, Director of GCARE at the University of Surrey, said: "As policymakers and political leaders rightly look to solve the nation's housing crisis, it is vitally important that they consider how this influx of new urban infrastructure will impact our environment and our planet."I hope that our study will give decision-makers the information they need when they are deciding which green infrastructure to establish in our communities. Our results suggest that, given a choice, trees are the most effective at reducing the urban heat island effect that many of our towns face."

Pollution

November 18, 2020

https://www.sciencedaily.com/releases/2020/11/201118080750.htm

Does air pollution affect mental health later in life?

In a study of women aged 80 years and older, living in locations with higher exposures to air pollution was associated with increased depressive symptoms. The findings are published in the

When looking at individual air pollutants, a team led by investigators from of the University of Southern California found that long-term exposure to nitrogen dioxide or fine particulate air pollution was associated with increased depressive symptoms, but with only a small effect. Results also suggested that depressive symptoms might play a role in linking long-term air pollution exposure to memory decline more than 10 years after the exposure."This is the first study showing how air pollution exposures affect depressive symptoms as well as the interrelationship between the symptoms and subsequent memory decline that had not been found in older people aged less than 80 years," said lead author Andrew Petkus, PhD.Senior author Jiu-Chiuan Chen, MD, ScD, added, "We know late-life exposures to ambient air pollutants accelerate brain aging and increase the dementia risk, but our new findings suggest the oldest-old populations may respond to air pollution neurotoxicity in a different way that needs to be investigated further."

Pollution

November 18, 2020

https://www.sciencedaily.com/releases/2020/11/201118090758.htm

Community helps scientists evaluate smoke forecasts

During the smoky summer of 2018, two wildfires in Utah County burned a combined 121,000 acres, sending smoke pouring into the valleys of the Wasatch Front. Atmospheric scientists are always working to better forecast how smoke moves from fires, just as they work to forecast hurricanes and snowstorms.

But the fires in 2018 provided a unique opportunity for scientists. Across the Wasatch Front, both researchers and community members maintain enough air quality sensors to provide a high-resolution picture of how the smoke moved through the valley -- perfect for testing and refining smoke forecast models."This forecast would be similar to how we would forecast rainy weather or clear conditions," says Derek Mallia, research assistant professor in the Department of Atmospheric Sciences, "except we can now do it for smoke."Mallia and his colleagues, including researchers from the Department of Chemical Engineering and School of Computing, published their results in the Journal of Geophysical Research-Atmospheres.Air quality is a high-priority topic for Utahns. Because of the Salt Lake Valley's mountainous geography, the area experiences wintertime temperature inversions that trap air pollution and emissions, often resulting in unhealthy air conditions. Researchers, particularly those at the U, have focused on understanding and measuring the air conditions in the valley through a network of research-grade sensors. They've also placed sensors on vehicles that move through the valley: TRAX light rail, Google StreetView cars and a van affectionately named the "NerdMobile."Members of the community also maintain their own sensors. Kerry Kelly, assistant professor of chemical engineering, and colleagues have developed low-cost interconnected particulate matter sensors that are maintained by homeowners throughout the Salt Lake Valley, improving the resolution of measurements. The low-cost sensor network is called Air Quality and yoU, or AQ&U. Air pollution is not distributed evenly, and all of these sensors together help researchers understand the where, when and why of polluted air.In Utah's summers, however, a temperature inversion isn't a problem. But smoke from Western wildfires is."From a practical standpoint, smoke is yet another variable that we need to account for in a weather forecast," Mallia says. "Similar to how unsettled weather such as snow or thunderstorms can impact our everyday activities, smoke can also play an important role." Particularly vulnerable, he says, are people with asthma or other respiratory or cardiovascular diseases. Smoke can also impact recreation. "Who wants to go sightseeing when Utah is blanketed in smoke?"Models that predict the movement of smoke need to be validated, or compared with observations, to make sure they're simulating smoke conditions with reasonable accuracy. But when wildfires occur in remote locations, the limited number of air quality sensors is usually not sufficient to evaluate models. That's where the Salt Lake Valley's air quality network comes in.In the 2018 fire season, nearly 60,000 fires burned nearly 9 million acres, including more than 18,000 homes, across the United States. Following months of hot and dry conditions, the Pole Creek and Bald Mountain Fires combined to burn nearly 121,000 acres in central Utah. The smoke-filled the valleys of the Wasatch Front, which were fortunately well-equipped with air quality instrumentation. When the fires were safely contained, the researchers saw a scientific opportunity.Mallia, Kelly, U research assistant professor Logan Mitchell and colleagues including professor Adam Kochanski of San Jose State University and professor Jan Mandel of CU Denver, looked at the data that came back from the sensors -- both the research-grade sensors and the low-cost versions at people's homes. Their results showed that measurements of particulate matter in the air by the low-cost sensors were accurate to within 10% of the measurements at nearby research-grade sensors.Smoke forecasts from the model captured the timing of smoke arrival, but not the amount -- the researchers found that the forecast overestimated the amount of smoke by a factor of two. That result helps the scientists to then go back to the model and figure out why so that the next version can be more accurate.The results also gave some insights into how the mountain valleys can disperse the smoke. "For example," Mallia says, "we found that canyon winds during the nighttime can filter cleaner mountain air into the valley, which is why we saw less polluted air near the valley benches."Mallia says that the sensors on TRAX trains were invaluable in covering more ground than a stationary air monitor, and that the involvement of community members, with sensors around their homes, was key to expanding the study area even further."There is a lot of space in the valley that is privately owned, so getting the public involved is the only way that we can properly sample different areas across the Salt Lake Valley," he says. "This allows us to sample more points in the valley and gives us greater confidence towards identifying the strengths and weaknesses of our smoke forecasts."Unfortunately, he adds, smoky days will become more frequent in the future. Climate change is projected to make hot and dry conditions more likely, which is the perfect recipe for more numerous and intense wildfires. Forecasts can't prevent the smoke from coming any more than weather forecasts can prevent blizzards or hurricanes -- but they can help all of us stay informed and prepared.

Pollution

November 17, 2020

https://www.sciencedaily.com/releases/2020/11/201117122834.htm

NASA model reveals how much COVID-related pollution levels deviated from the norm

Since the COVID-19 pandemic began, space- and ground-based observations have shown that Earth's atmosphere has seen significant reductions in some air pollutants. However, scientists wanted to know how much of that decline can be attributed to changes in human activity during pandemic-related shutdowns, versus how much would have occurred in a pandemic-free 2020.

Using computer models to generate a COVID-free 2020 for comparison, NASA researchers found that since February, pandemic restrictions have reduced global nitrogen dioxide concentrations by nearly 20%. The results were presented at the 2020 International Conference for High Performance Computing, Networking, Storage, and Analysis.Nitrogen dioxide is an air pollutant that is primarily produced by the combustion of fossil fuels used by industry and transportation -- both of which were significantly reduced during the height of the pandemic to prevent the novel coronavirus from spreading."We all knew the lockdowns were going to have an impact on air quality," said lead author Christoph Keller with Universities Space Research Association (USRA) at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Keller works in Goddard's Global Modeling and Assimilation Office (GMAO), which uses high-tech computer models to help track the chemistry of the ocean and the atmosphere, and forecast future climate scenarios. He says, "it was also soon clear that it was going to be difficult to quantify how much of that change is related to the lockdown measures, versus general seasonality or variability in pollution."No two years are exactly alike. Normal variations in weather and atmospheric circulation change the make-up and chemistry of Earth's atmosphere. Comparing 2020 nitrogen dioxide concentrations with data from 2019 or 2018 alone would not account for year-to-year differences. But, because the NASA model projections account for these natural variations, scientists can use them to parse how much of the 2020 atmospheric composition change was caused by the COVID-19 containment measures.Even with models, there was no predicting the sudden, drastic shifts in human behavior as the novel coronavirus -- and the regulations attempting to control it -- spread rapidly. Instead of trying to re-program their model with this unexpected event, Keller and his colleagues accounted for COVID-19 by having the model ignore the pandemic altogether.The model simulation and machine learning analysis took place at the NASA Center for Climate Simulation. Its "business as usual" scenario showed an alternate reality version of 2020 -- one that did not experience any unexpected changes in human behavior brought on by the pandemic.From there it is simple subtraction. The difference between the model simulated values and the measured ground observations represents the change in emissions due to the pandemic response. The researchers received data from 46 countries -- a total of 5,756 observation sites on the ground -- relaying hourly atmospheric composition measurements in near-real time. On a city-level, 50 of the 61 analyzed cities show nitrogen dioxide reductions between 20-50%."In some ways I was surprised by how much it dropped," said Keller. "Many countries have already done a very good job in lowering their nitrogen dioxide concentrations over the last decades due to clean air regulations, but what our results clearly show is that there is still asignificant human behavior-driven contribution."Wuhan, China was the first municipality reporting an outbreak of COVID-19. It was also the first to show reduced nitrogen dioxide emissions -- 60% lower than simulated values expected. A 60% decrease in Milan and a 45% decrease in New York followed shortly, as their local restrictions went into effect."You could, at times, even see the decrease in nitrogen dioxide before the official policies went into place," said co-author Emma Knowland with USRA at Goddard's GMAO. "People were probably reducing their transit because the talk of the COVID-19 threat was already happening before we were actually told to shut down." Once restrictions were eased, the decreases in nitrogen dioxide lessened, but remained below expected "business as usual" values.Keller compared his estimates of the nitrogen dioxide decreases to reported economic numbers, namely, the gross domestic products, of the nations included in the study. According to Keller, they lined up shockingly well. "We would expect them to be somewhat related because nitrogen dioxide is so closely linked to economic activities, like people who travel and factories running," he said. "It looks like our data captures this very well."The research is ongoing, and the GEOS model data used in this study are publicly available.More information about GEOS can be found at:

Pollution

November 17, 2020

https://www.sciencedaily.com/releases/2020/11/201117085930.htm

Tropical peatland conservation could protect humans from new diseases

Conservation of tropical peatlands could reduce the impacts of the COVID-19 pandemic and the likelihood of new diseases jumping from animals to humans, researchers say.

The scientists reviewed existing evidence and concluded the high biodiversity in tropical peat-swamp forests, combined with habitat destruction and wildlife harvesting, created "suitable conditions" for emerging infectious diseases (EIDs) that could jump to humans.COVID-19 did not emerge in a tropical peatland area -- but HIV/AIDS and the joint-first case of Ebola both originated in areas with extensive peatlands.The study also assessed the possible impact of COVID-19 on tropical peatland conservation and local communities -- and identified "numerous potential threats" to both.Led by the University of Exeter, the international study team comprised researchers from countries with large tropical peatlands, including Indonesia, DR Congo and Perú."We're not saying tropical peatlands are unique in this respect -- but they are one important habitat where zoonotic diseases (those that jump from animals to humans) could emerge," said lead author Dr Mark Harrison, of the Centre for Ecology and Conservation on Exeter's Penryn Campus in Cornwall, UK and Borneo Nature Foundation International."Tropical peat-swamp forests are rich in fauna and flora, including numerous vertebrates known to represent zoonotic EID risk, such as bats, rodents, pangolins and primates."Exploitation and fragmentation of these habitats, as well as peat wildfires (ultimately driven by human activity) and wildlife harvesting bring more and more people into close contact with peatland biodiversity, increasing the potential for zoonotic disease transmission."Our review shows that protecting tropical peatlands isn't therefore just about wildlife and carbon emissions -- it's also important for human health."The study also notes "high impacts" of COVID-19 in some countries with large tropical peatland areas, some of which are relatively poorly resourced to tackle pandemics."Many communities in these areas are remote, relatively poor, disconnected, have limited infrastructure, sub-standard or non-existent medical facilities, and depend heavily on external trade," said Dr Ifo Suspense, of Université Marien, Republic of Congo, who contributed to the review."As a result, the direct and indirect impacts of COVID-19 may be particularly severe in these communities."Dr Muhammad Ali Imron, from University Gadjah Mada in Indonesia, who was also involved in the study, said: "Additionally, major wildfires in peatland areas cause massive air pollution, particularly in South East Asia, increasing the threat to human health from respiratory diseases like COVID-19."In terms of the impacts on peatlands themselves, we reveal that conservation, research and training are all being affected by the pandemic, which may result in increased habitat encroachment, wildlife harvesting and fires started to clear vegetation."The study concludes: "Sustainable management of tropical peatlands and their wildlife is important for mitigating impacts of the COVID-19 pandemic, and reducing the potential for future zoonotic EID emergence and severity, thus strengthening arguments for their conservation and restoration."To help achieve this, the study identifies a number of opportunities and recommendations for researchers, field projects, policy makers and donors to help achieve this goal.

Pollution

November 17, 2020

https://www.sciencedaily.com/releases/2020/11/201117085924.htm

Reducing aerosol pollution without cutting carbon dioxide could make the planet hotter

Humans must reduce carbon dioxide and aerosol pollution simultaneously to avoid weakening the ocean's ability to keep the planet cool, new research shows.

Aerosol pollution refers to particles in the air emitted by vehicles and factories that burn fossil fuels. This pollution contributes to asthma, bronchitis, and long-term irritation of the respiratory tract, which can lead to cancer."The conundrum," explained UC Riverside climate scientist and study co-author Robert Allen, "is that aerosols cause poor air quality and lead to premature deaths. However, these particles have a net cooling impact on the climate, so when you cut them that leads to a net warming effect."Much research has examined aerosol impacts on air quality and land surface temperatures. Less explored is the way aerosols might impact the oceans, which is the focus of a UC Riverside study now published in the journal The research team created detailed computer models to determine the impact on oceans under two different scenarios -- one in which there is only a reduction in aerosols, and another scenario in which greenhouse gases like carbon dioxide and methane are also reduced."The first scenario leads to the surprising result that fewer aerosols in the atmosphere could shift the region where most of the ocean is taking up heat, from the Southern Ocean toward the North Atlantic," Allen said.In particular, the Atlantic meridional overturning circulation, or AMOC, would be disturbed as aerosols are removed from the atmosphere, the study found. The AMOC pulls warm water further north and pushes colder water south, ensuring the climate on land areas at higher latitudes, such as Europe, are relatively mild.Roughly half the carbon dioxide humans put into the atmosphere -- mostly through fossil fuel combustion and deforestation -- stays there, and the remaining half is taken up by land and vegetation, as well as the ocean.One of the ways the ocean takes up our carbon dioxide emissions is through AMOC circulation."A projected decline in humanmade aerosols potentially induces a weakening of the AMOC, which plays an important role in ocean heat uptake and storage in the North Atlantic," said Wei Liu, an assistant professor of climate change and sustainability at UCR.In addition, the researchers said a rise in sea level would occur if the North Atlantic Ocean were to get warmer.This current study focused on ocean heat uptake and circulation via the AMOC. However, Allen explained the study did not attempt to rigorously identify the mechanisms by which aerosol reductions weaken the AMOC. Those mechanisms will be the focus of future studies.Ultimately, the researchers conclude that even without a more in-depth explanation of the weakening mechanisms, it is necessary to reduce greenhouse gases and aerosols in tandem.The Intergovernmental Panel on Climate Change recommends making every attempt to prevent the planet from reaching 1.5 degrees Celsius above pre-industrial levels in order to mitigate the worst effects of global warming.Humans have already increased carbon dioxide levels by almost 50% since the 1850s, and it continues to increase worldwide. Stabilizing carbon dioxide at current levels would require zero net emissions before the year 2070, which is ambitious, but critical."Assuming complete removal, aerosols at most will cause warming of about 1 K," said Allen. "However, aerosol-induced warming, as well as the associated ocean circulation changes, can be moderated by rigorous cuts in greenhouse gases including methane and carbon dioxide."

Pollution

November 17, 2020

https://www.sciencedaily.com/releases/2020/11/201117085940.htm

Pesticides commonly used as flea treatments for pets are contaminating English rivers

Researchers at the University of Sussex have found widespread contamination of English rivers with two neurotoxic pesticides commonly used in veterinary flea products: fipronil and the neonicotinoid imidacloprid. The concentrations found often far exceeded accepted safe limits.

These chemicals are banned for agricultural use due to the adverse environmental effects, but there is minimal environmental risk assessment for pesticides used on domestic cats and dogs. This is due to the assumption that there are likely to be fewer environmental impacts due to the amount of product used.But there is growing concern that this assumption may be incorrect. To investigate this, Professor Dave Goulson and Rosemary Perkins from the University of Sussex analysed data gathered by the Environment Agency in English waterways between 2016-18. They found that fipronil was detected in 98% of freshwater samples, and imidacloprid in 66%.Rosemary Perkins, a PhD student at Sussex and a qualified vet, said: "The use of pet parasite products has increased over the years, with millions of dogs and cats now being routinely treated multiple times per year.""Fipronil is one of the most commonly used flea products, and recent studies have shown that it degrades to compounds that are more persistent in the environment, and more toxic to most insects, than fipronil itself. Our results, showing that fipronil and its toxic breakdown products are present in nearly all of the freshwater samples tested, are extremely concerning."According to the Veterinary Medicines Directorate (VMD), who funded the research, there are 66 licensed veterinary products containing fipronil in the UK, and 21 containing imidacloprid, either alone or in combination with other parasiticides. These include spot-on solutions, topical sprays and collars impregnated with the active ingredient.While some of these products can be purchased only with a veterinary prescription, others can be bought without a prescription from pet shops, supermarkets, pharmacies and online. Many pet owners receive year-round preventative flea and/or tick treatment from their vet practice via healthcare plans.Fipronil has a history of very limited agricultural use prior to its ban in 2017. It is also licensed for use in ant and cockroach baits, however only one product is licensed for use by non pest-control professionals. Use on pets seems to be the most plausible source of the widespread contamination of rivers.The paper, co-authored with Martin Whitehead from the Chipping Norton Veterinary Hospital and Wayne Civil at the Environment Agency, examines the occurrence of fipronil and imidacloprid in English rivers as indicators of the potential contamination of waterways from the use of pet flea treatments.They found that the average fipronil concentration across the rivers sampled by the Environment Agency exceeded chronic safety thresholds five-fold. The overall pollution levels in English rivers indicate that fipronil and its toxic breakdown products pose a high risk to aquatic ecosystems.While, in most rivers, imidacloprid was found to pose a moderate risk, in seven out of the 20 rivers sampled there was a high environmental risk.Co-author Professor Dave Goulson said "Fipronil and imidacloprid are both highly toxic to all insects and other aquatic invertebrates. Studies have shown both pesticides to be associated with declines in the abundance of aquatic invertebrate communities. The finding that our rivers are routinely and chronically contaminated with both of these chemicals and mixtures of their toxic breakdown products is deeply troubling."The paper, published in Bathing of pets treated with spot-on fipronil flea products has been confirmed as a potentially important route to waterways for fipronil via sewers, and the washing of hands, pet bedding or other surfaces that have come into contact with treated pets are potential additional pathways for entry to sewers. Other pathways for contamination of waterways includes swimming and rainfall wash-off from treated pets. The strong correlation between fipronil and imidacloprid levels across the river sites tested suggest that they may be coming from a common source.Rosemary Perkins added: "We've identified a number of steps that can be taken to minimise or avoid environmental harm from pet flea and/or tick treatments. These range from introducing stricter prescription-only regulations, to considering a more judicious and risk-based approach to the control of parasites in pets, for example by moving away from blanket year-round prophylactic use."We'd recommend a re-evaluation of the environmental risks posed by pet parasite products, and a reappraisal of the risk assessments that these products undergo prior to regulatory approval."

Pollution

November 16, 2020

https://www.sciencedaily.com/releases/2020/11/201116075736.htm

Plastic pollution is everywhere. Study reveals how it travels

Plastic pollution is ubiquitous today, with microplastic particles from disposable goods found in natural environments throughout the globe, including Antarctica. But how those particles move through and accumulate in the environment is poorly understood. Now a Princeton University study has revealed the mechanism by which microplastics, like Styrofoam, and particulate pollutants are carried long distances through soil and other porous media, with implications for preventing the spread and accumulation of contaminants in food and water sources.

The study, published in Datta led the research team, which found that the microparticles are pushed free when the rate of fluid flowing through the media remains high enough. The Princeton researchers showed that the process of deposition, or the formation of clogs, and erosion, their breakup, is cyclical; clogs form and then are broken up by fluid pressure over time and distance, moving particles further through the pore space until clogs reform."Not only did we find these cool dynamics of particles getting stuck, clogged, building up deposits and then getting pushed through, but that process enables particles to get spread out over much larger distances than we would have thought otherwise," said Datta.The team included Navid Bizmark, a postdoctoral research associate in the Princeton Institute for the Science and Technology of Materials, graduate student Joanna Schneider, and Rodney Priestley, professor of chemical and biological engineering and vice dean for innovation.They tested two types of particles, "sticky" and "nonsticky," which correspond with actual types of microplastics found in the environment. Surprisingly, they found that there was no difference in the process itself; that is, both still clogged and unclogged themselves at high enough fluid pressures. The only difference was where the clusters formed. The "nonsticky" particles tended to get stuck only at narrow passageways, whereas the sticky ones seemed to be able to get trapped at any surface of the solid medium they encountered. As a result of these dynamics, it is now clear that even "sticky" particles can spread out over large areas and throughout hundreds of pores.In the paper, the researchers describe pumping fluorescent polystyrene microparticles and fluid through a transparent porous media developed in Datta's lab, and then watching the microparticles move under a microscope. Polystyrene is the plastic microparticle that makes up Styrofoam, which is often littered into soils and waterways through shipping materials and fast food containers. The porous media they created closely mimics the structure of naturally-occurring media, including soils, sediments, and groundwater aquifers.Typically porous media are opaque, so one cannot see what microparticles are doing or how they flow. Researchers usually measure what goes in and out of the media, and try to infer the processes going on inside. By making transparent porous media, the researchers overcame that limitation."Datta and colleagues opened the black box," said Philippe Coussot, a professor at Ecole des Ponts Paris Tech and an expert in rheology who is unaffiliated with the study."We figured out tricks to make the media transparent. Then, by using fluorescent microparticles, we can watch their dynamics in real time using a microscope," said Datta. "The nice thing is that we can actually see what individual particles are doing under different experimental conditions."The study, which Coussot described as a "remarkable experimental approach," showed that although the Styrofoam microparticles did get stuck at points, they ultimately were pushed free, and moved throughout the entire length of the media during the experiment.The ultimate goal is to use these particle observations to improve parameters for larger scale models to predict the amount and location of contamination. The models would be based on varying types of porous media and varying particle sizes and chemistries, and help to more accurately predict contamination under various irrigation, rainfall, or ambient flow conditions. The research can help inform mathematical models to better understand the likelihood of a particle moving over a certain distance and reaching a vulnerable destination, such as a nearby farmland, river or aquifer. The researchers also studied how the deposition of microplastic particles impacts the permeability of the medium, including how easily water for irrigation can flow through soil when microparticles are present.Datta said this experiment is the tip of the iceberg in terms of particles and applications that researchers can now study. "Now that we found something so surprising in a system so simple, we're excited to see what the implications are for more complex systems," said Datta.He said, for example, this principle could yield insight into how clays, minerals, grains, quartz, viruses, microbes and other particles move in media with complex surface chemistries.The knowledge will also help the researchers understand how to deploy engineered nanoparticles to remediate contaminated groundwater aquifers, perhaps leaked from a manufacturing plant, farm, or urban wastewater stream.Beyond environmental remediation, the findings are applicable to processes across a spectrum of industries, from drug delivery to filtration mechanisms, effectively any media in which particles flow and accumulate, Datta said.

Pollution

November 13, 2020

https://www.sciencedaily.com/releases/2020/11/201113154626.htm

How air pollution affects homeless populations

When air quality worsens, either from the smoke and ozone of summer or the inversion of winter, most of us stay indoors. But for individuals experiencing homelessness, that's not always an option. In a new study, researchers from the University of Utah document the effect of air pollution on people experiencing homelessness, finding that nearly all notice and are impacted by air pollution, whether or not they reside in shelters.

The study, funded by the Interdisciplinary Exchange for Utah Science (NEXUS) at the University of Utah, is published in the People experiencing homelessness, particularly those who sleep outdoors at night, are the most vulnerable and exposed population to environmental hazards, says Daniel Mendoza, a research assistant professor in the Department of Atmospheric Sciences and visiting assistant professor in the Department of City & Metropolitan Planning. Mendoza also holds appointments as an adjunct assistant professor in the Pulmonary Division in the School of Medicine and as a senior scientist at NEXUS. "Many individuals sleep near a road or under a bridge," he says, "which leads to exposure to high levels of traffic related emissions. Further compounding the issue is the fact that during sleep, many people breathe through their mouth and breathe more deeply."This life lived outdoors makes homelessness an environmental justice issue, says Jeff Rose, assistant professor in the Department of Parks, Recreation and Tourism."People experiencing unsheltered homelessness often live, eat, sleep, socialize, use the bathroom, and other basic human functions outdoors, with close and regular interaction with the environment," he says. Environmental justice research looks at uneven exposures to pollution and other environmental risks. "Increasingly, scholars are considering people experiencing unsheltered homelessness as fitting in this framework."While other researchers have looked at how people experiencing homelessness experience environmental injustice in the form of access to safe drinking water or parks, the U team says it is among the first to look at how people experiencing homelessness also experience the intermittent poor air quality of Salt Lake County.To collect people's stories, Angelina DeMarco, a doctoral student in anthropology and Rebecca Hardenbrook, a doctoral student in mathematics, went to several Salt Lake City resource centers to meet with people experiencing sheltered homelessness."We sat in the dining hall of each center and invited all residents that came by to interview," DeMarco says. In partnership with the Volunteers of America outreach team, they also interviewed people at the Salt Lake City library, on downtown streets, outside the St. Vincent de Paul dining hall and at local parks. Outdoor interviews took place often during harsh winter conditions, DeMarco says.They interviewed everyone they encountered, 138 people total, and asked them open-ended questions about when and how they knew the air was polluted, and how air pollution make them feel. With the interviewees' permission, the researchers also examined health records kept by the state Homeless Management Information System.More than half of the participants reported having physical reactions to air pollution including headaches and difficulty breathing, and more than a third reported emotional stress associated with air pollution. 89% reported seeking medical treatment for their symptoms.But the researchers also wanted to look at whether the duration of homelessness or residing within a shelter would affect individuals' experiences with air pollution. Surprisingly, they found no significant differences in heart and lung health outcomes between sheltered and unsheltered individuals, as well as between people experiencing chronic (more than a year) or non-chronic homelessness."These results indicate that sheltered and unsheltered, short-term and long-term homeless populations experience negative health outcomes that are associated with air pollution," DeMarco says. The mental health impacts of air pollution exposure, she says, merit additional study.The message for governmental leaders, the researchers say, is that shelters and day centers that protect people from the elements may not be shielding them from air pollution and other environmental impacts, which can have a significant effect on their health. Affordable housing policies and efforts to place people experiencing homelessness in housing, they say, may do much more to protect a vulnerable population from an environmental hazard.

Pollution

November 12, 2020

https://www.sciencedaily.com/releases/2020/11/201112145435.htm

Pollution and pandemics: A dangerous mix

The United States may have set itself up for the spread of a pandemic without even knowing it.

According to new research from the McKelvey School of Engineering at Washington University in St. Louis, pollution may bear part of the blame for the rapid proliferation in the United States of SARS-CoV-2, the virus responsible for the spread of COVID-19.The research, from the lab of Rajan Chakrabarty, associate professor in the Department of Energy, Environmental & Chemical Engineering, was published online ahead of print in the journal When it comes to how ill someone gets after contracting COVID-19, medical professionals believe that a person's health -- having certain medical conditions, for example -- can play a vital role. When it comes to how fast the virus can spread through the community, it turns out the health of the environment is directly correlated to the basic reproduction ratio R0, which denotes the expected number of people each sick person can infect.The reproduction ratio R0 of COVID-19 associates directly with the long-term ambient PM2.5 exposure levels. And the presence of secondary inorganic components in PM2.5 only makes things worse, according to Chakrabarty."We checked for more than 40 confounding factors," Chakrabarty said. Of all of those factors, "There was a strong, linear association between long-term PM2.5 exposure and R0."PM2.5 refers to ambient particles with a diameter of 2.5 micrometers or less; at that size, they can enter a person's lungs and cause damage. For this reason, PM2.5 can be detrimental to respiratory health. But how this relates to the spread of COVID-19 through a population had yet to be explored.Chakrabarty and his graduate student Payton Beeler, both aerosol researchers who have done previous coronavirus modeling, became interested in the relationship after two papers were published in quick succession. First, a July paper in the journal Science found that levels of susceptibility to COVID-19 is a driving factor for the pandemic; it is more important than temperature, which researchers initially thought might play an outsized role.Then in August, research published in the Journal of Infection found that the highest number of cases of COVID-19 with severe illness were in places with higher pollution levels."I was thinking, why, in the majority of the U.S. states, have we had such a rapid spread of the virus?" Chakrabarty said. Particularly in the earlier stages of the pandemic. "We wanted to confine our study to the point in time when the shutdown was in place. For the most part, people did remain confined from early March until the end of April."The team decided to look at places where R0 was greater than one -- that's the point at which one person can spread an illness to more than one person, and the illness takes off. In those places, they looked at 43 different factors -- including population density, age distribution, even time delays in states' stay-at-home orders.Then, using pollution estimates across the U.S. between 2012 and 2017 published by Randall Martin, professor in the Department of Energy, Environmental & Chemical Engineering, the team looked for any relationships.Modeling revealed an increase of almost 0.25 in R0 corresponding to a 10% increase in sulfate, nitrogen dioxide and ammonium, or SNA composition and an increase of 1 ?g/m3 in PM2.5 mass concentrations, respectively.They found these linear correlations to be strongest in places where pollution levels were well below National Ambient Air Quality Standards (NAAQS), the levels of air pollutants that are considered safe for humans."Annual mean PM2.5 national standards are set at or below 12 micrograms per cubic meter, below that you are supposed to be safe," Chakrabarty said. "What we saw, the correlation we're seeing is well below that standard." In fact, they saw a rapid increase in R0 when PM2.5 exposure levels were below 6 micrograms per cubic meter.Chakrabarty hypothesizes this initial increase in R0, which is followed by a plateau once levels hit 6 micrograms per cubic meter, is a result of initial changes in condition; when the air is free of PM2.5 , an individual is unaffected. The initial exposure is the catalyst for change in lung health resulting in a change from non-susceptibility to susceptibility, which is reflected in the increasing R0.And although there was no direct correlation between black carbon -- a.k.a. soot -- and R0, researchers did find a connection."Our collaborators at Saint Louis University suggested a mediation/moderation statistical approach," a detailed analysis that looks at the way additional variables affect the outcome of the initial relationship. In this case, researchers looked at soot's effect on R0, considering SNA's effect."We found black carbon acts as a kind of catalyst. When there is soot present, PM2.5 has more of an acute effect on lung health, and therefore on R0."The mediation/moderation study was not superfluous -- one of the common ways people are exposed to SNA is through pollution emitted from cars and coal-fired power plants. Both of which also emit soot."Although decades of strict air quality regulations in the U.S. have resulted in significant reductions of nitrogen dioxide levels," the authors wrote in the paper's conclusion, "recent reversal of environmental regulations which weaken limits on gaseous emissions from power plants and vehicles threaten the country's future air quality scenario.""Instead of working to resolve this issue, these reversals may be setting us up for another pandemic," Chakrabarty said.The authors have made their data and source codes available to the public (see:

Pollution

November 12, 2020

https://www.sciencedaily.com/releases/2020/11/201112080901.htm

Early-life events linked to lung health in young adulthood

Early-life events, such as the exposure to air pollutants, increases the risk of chronic lung disease in young adulthood, according to new results by researchers at Karolinska Institutet, Sweden, published in the

Chronic bronchitis and chronic obstructive pulmonary disease (COPD), with the hallmark features phlegm and irreversible airflow limitation, respectively, are lung diseases known to affect adults with a history of long-term smoking."To our surprise, we found the prevalence of chronic bronchitis and irreversible airflow limitation to be rather high (5.5% and 2.0%, respectively), considering the young age of the study participants." says senior author Erik Melen, professor and paediatrician , Department of Clinical Science and Education, Karolinska Institutet, Sodersjukhuset."Those diseases are usually diagnosed in patients older than 50 years of age," comments further co-author Anders Linden, professor and pulmonologist, Institute of Environmental Medicine.In the present studies, the researchers used data from birth up to age 24 years from the follow-up of the Swedish population-based birth cohort BAMSE (Swedish abbreviation for Child (Barn), Allergy, Milieu, Stockholm, Epidemiological), which includes 4,089 participants from the Stockholm area recruited 1994-96.Analyses performed by PhD student Gang Wang showed that smoking as well as early-life air pollution exposures and childhood asthma are risk factors for chronic bronchitis, whereas breast-feeding was identified as a protective factor.In addition, the early-life risk factors for development of irreversible airflow limitation were recurrent lung infections, asthma, and exposure to air pollution."The levels of air pollutants in the current study mainly reflect local emissions from road traffic, which implies that this preventable risk factor may play an important role in the development of chronic lung disease in young adults." says professor Erik Melen.Given that air pollution levels in Stockholm are comparatively low by international standards, this makes the current findings very important in a global context. And despite the young participants' age, active smoking was linked to chronic bronchitis, which underlines the negative health effects from even a limited period of exposure to tobacco smoke."In conclusion, our two novel studies demonstrate that chronic bronchitis and irreversible airflow limitation do exist in young adults and emphasize the importance of early-life events for maintaining lung health during adulthood. The take home-message is: If you want to prevent disease, early prevention is the key to success."The study was financially supported by the European Research Council (TRIBAL, 757919), the Swedish Research Council, the Swedish Heart-Lung Foundation, Region Stockholm and the China Scholarship Council.

Pollution

November 12, 2020

https://www.sciencedaily.com/releases/2020/11/201112093115.htm

Governments can curb over-fertilization in agriculture

The world is awash with nitrogen. In agriculture, nitrogen is used as a fertiliser to increase output, but this causes one of the biggest environmental problems of our time. Nitrogen pollution has detrimental effects on water and soil and is also harmful to human and animal health. What's more, when the air or rain carry nitrogen into unfertilised habitats, such as bogs or forests, it causes a decline in natural biodiversity.

National governments have it within their power to curb the problem. What is required are national and international policies that steer the global food system towards higher yields and a much lower environmental impact. However, research to date has barely touched on the extent to which countries actually influence their nitrogen pollution and their crop yields.Now, ETH researchers David Wüpper and Robert Finger from the Chair of Agricultural Economics and Policy have joined forces with other international authors to investigate for the first time the overall impact of almost every country in the world on their nitrogen pollution and crop yields. The results of their study were recently published in the journal In this publication, the researchers show that countries do in fact have a major impact, especially on levels of nitrogen pollution. In fact, countries' impact on pollution is often multiple times greater than their effect on crop yields.In many countries much greater use of nitrogen fertiliser has only marginally reduced their yield gap -- the difference between potential yield and the actual yield achieved. Overall, when individual countries attempt to close the yield gap by 1 percent, this is associated with a 35 percent rise in nitrogen pollution on a global scale. In other words, some countries are using enormous amounts of fertiliser but achieve very little in the way of additional yield. This leads the researchers to conclude that many countries could curb their fertiliser use without seeing yield reductions.In their study, they also identified the factors that explain overall nitrogen use and pollution relative to their crop yields. Key factors include the quality of institutions, the degree of economic development and the size of the population, for example, but also the share of agriculture in the country's total economy.Another major factor that influences a country's nitrogen pollution is direct state subsidies to reduce the cost of nitrogen fertiliser. However, indirect subsidies and policy measures that affect the price of agricultural products in relation to fertiliser costs also play a role, as do regulations and laws, farmer training, technology and even trade structures.One example of how country-specific factors influence nitrogen pollution can be seen at the border between Kazakhstan and China, a region that is naturally dry with sparse vegetation. Satellite images show that on the Chinese side the vegetation is lush and green right up to the border, but on the Kazakh side it changes abruptly and becomes less green. This points to the presence of irrigation and ample amounts of nitrogen fertiliser on the Chinese side."Such a marked difference in the vegetation can't be a natural phenomenon," says Wüpper, lead author of the study. "This example illustrates that the country in which the fields are located is a decisive factor for yield and nitrogen pollution," he explains. "However, it would be possible for China to achieve a similar yield with significantly less nitrogen pollution."Also Switzerland is hardly a poster child for nitrogen pollution levels. Like other European countries, but considerably more, it continues to apply nitrogen fertiliser in great volumes that are too much for the crops to fully absorb. The surplus ends up in streams, lakes and other ecosystems."Agriculture in Switzerland is very intensive," Wüpper says. He explains that this has a direct impact on nitrogen pollution, not least because the fodder that Swiss animals eat comes from abroad. However, the manure produced by the livestock is spread on Swiss soil, where it contributes to the levels of nitrogen pollution."Overall, however, there's an uneven balance in the distribution of fertiliser resources around the globe," the researchers say to sum up. While Switzerland has an oversupply, other regions of the world don't have enough. In parts of sub-Saharan Africa, for example, farmers underuse nitrogen fertiliser. However, if they were to increase their use of nitrogen fertiliser only marginally, they would be able to significantly increase their yields. Mitigating this global fertiliser imbalance would enable yields to be considerably increased in some places and pollution to be greatly reduced in others.One way to achieve this would be to adjust the cost of nitrogen fertiliser. In countries where too much is used, the cost of fertiliser should go up, e.g. by introducing a nitrogen tax, or by other policy instruments and adjustments. Conversely, in countries in which too little nitrogen fertilizer is used, the price should go down, e.g. by introducing a nitrogen subsidy, or by other policy instruments and adjustments.Another approach involves changes on farms themselves. Government and industry could offer farmers incentives to make their crop production more environmentally friendly. They could, for example, promote certain production processes that increase the efficiency of nitrogen use. Moreover, farmers who use less nitrogen and consequently have to contend with lower yields could receive financial compensation from the state.New technologies could also increase nitrogen efficiency. "We're talking about what's known as precision agriculture, a concept in which fertiliser is applied only where it is actually needed. This can increase the efficiency of use and reduce environmental problems without decreasing output," Finger explains."But consumption can also make a big difference," Wüpper adds. He points out that one-third of all food produced goes to waste, intensifying nitrogen pollution and environmental damage. "If we cut down on food waste, we reduce environmental problems, too," he says. A much meat-reduced diet also helps to cut back excess levels of fertiliser because if farmers produce less meat, less manure ends up on the fields.

Pollution

November 11, 2020

https://www.sciencedaily.com/releases/2020/11/201111144431.htm

Atmospheric rivers help create massive holes in Antarctic sea ice

Warm, moist rivers of air in Antarctica play a key role in creating massive holes in sea ice in the Weddell Sea and may influence ocean conditions around the vast continent as well as climate change, according to Rutgers co-authored research.

Scientists studied the role of long, intense plumes of warm, moist air -- known as atmospheric rivers -- in creating enormous openings in sea ice. They focused on the Weddell Sea region of the Southern Ocean near Antarctica, where these sea ice holes (called polynyas) infrequently develop during the winter. A large hole in this area was first observed in 1973 and a hole developed again in the late winter and early spring of 2017.In the first study of its kind, published in the journal "Polynyas strongly influence the physical and ecological dynamics of the Southern Ocean," said co-author Kyle Mattingly, a post-doctoral researcher at the Rutgers Institute of Earth, Ocean, and Atmospheric Sciences. "They serve as giant 'windows' in the sea ice that allow large amounts of heat to move from the ocean to the atmosphere, modifying regional and global ocean circulation. They also affect the timing and magnitude of phytoplankton (algae) blooms, which are the base of the marine food web. Our study will pave the way for greater understanding of climate variability and climate change in these regions."Previous studies have found that atmospheric rivers influence melting of West Antarctic land ice and ice shelves, and the new study builds on those findings by showing their effects on Antarctic sea ice for the first time. The rivers are thousands of miles long and the sea ice holes cover thousands of square miles, usually at specific locations that are primed by local ocean circulation conditions.West Antarctica, an enormous ice sheet that sits on land, is melting and contributing to global sea-level rise, and the melting has accelerated in the 21st century. If the entire Antarctic Ice Sheet melted, the ocean level would rise by about 200 feet, according to the National Snow & Ice Data Center. Sea-level rise and flooding from coastal storms threaten coastal communities worldwide, especially in low-lying areas.Under projected future climate change, atmospheric rivers are predicted to become more frequent, longer, wider and more effective in moving high levels of water vapor toward the Antarctic Ocean and continent, along with increasing the intensity of precipitation. In general, where they make landfall is predicted to shift toward the poles, and the effect of climate change on sea ice holes in the Weddell Sea and elsewhere in the Southern Ocean is an important area for future research.Co-authors include scientists at Khalifa University of Science and Technology, Stevens Institute of Technology and the Australian Antarctic Division and Australian Antarctic Program Partnership.

Pollution

November 11, 2020

https://www.sciencedaily.com/releases/2020/11/201111122823.htm

Noise and light can 'profoundly' alter bird reproduction

Looking for a bird's-eye view of human impact? A new study published in the journal

Recent troubling findings suggest bird populations have declined by more than 30% in the last few decades. To develop effective strategies to reverse this trend, scientists and land managers need to understand what caused the decline.The effects of noise and light pollution on the health of bird populations had been largely overlooked until some recent studies suggested that these stressors can harm individual species. With this new study, a continent-wide picture has emerged."Our study provides the most comprehensive evidence that noise and light can profoundly alter reproduction of birds, even when accounting for other aspects of human activities," said Clint Francis, a biologist at California Polytechnic State University and one of the lead study authors.Researchers looked at a huge collection of data sets -- including those collected by citizen scientists through the NestWatch Program -- to assess how light and noise affected the reproductive success of 58,506 nests from 142 species across North America. The team considered several factors for each nest, including the time of year breeding occurred and whether at least one chick fledged from the nest.Birds time their reproduction to coincide with peak food availability to feed their young, using daylight cues to breed about the same time each year. The researchers found that light pollution causes birds to begin nesting up to a month earlier than normal in such open environments as grasslands or wetlands and 18 days earlier in forested environments. The consequence could be a mismatch in timing -- hungry chicks may hatch before their food is readily available. If that happens, these early season nests may be less successful at fledging at least one chick, but the situation is complicated by climate change.As the planet warms, birds' food is available earlier due to warmer weather. Birds that maintain their historical breeding times because their internal clocks are set to changes in day length may have fewer chicks survive because the food source they rely on already came and went."We discovered that the birds that advanced the timing of their reproduction in response to increased light pollution actually have better reproductive success," Francis said. "A likely interpretation of this response is that light pollution actually allows these birds to 'catch up' to the shift towards earlier availability of food due to climate change."These findings suggest two conclusions about how birds respond to climate change. First, at least temporarily, birds in areas impacted by light pollution may track climate change better than those in in natural habitats that are darker. Second, when scientists thought birds were adjusting their reproductive timing to climate change, birds actually may have been responding instead to the light cues because many studies were done in areas exposed to some light pollution.When considering noise pollution, results showed that birds living in forested environments tend to be more sensitive to noise than birds in open environments.Researchers delved into greater detail for 27 species looking for physical traits that could explain the variations in species' responses to light and noise. A bird's ability to see in low light and the pitch of its call were related to species' responses to light and noise pollution, respectively.The more light a bird's eye is capable of taking in, the more that species moved its breeding time earlier in the year in response to light pollution and the more that species experienced improved nest success as a result of light pollution. Noise pollution delayed nesting for birds' whose songs are at a lower frequency and thus more difficult to hear through low-frequency human noise. Mating decisions are made based on the male's song, and in some cases, females need to hear the male's song to become physically ready to breed.These trait and environment-specific results have strong implications for managing wildlands."We show convincingly across a lot of species that noise and light pollution are having strong effects on wild populations," Francis said. "If there's a proposed development and land managers are worried about a bird that they have no information on, they can use this study to see whether the development is likely to affect the bird. Is it a forest bird? If so, it is likely that it is more sensitive to light and noise."The study is the first step toward a larger goal of developing a sensitivity index for all North American birds. The index would allow managers and conservationists to cross-reference multiple physical traits for a species to assess how factors such as light and noise pollution would affect it and each species.

Pollution

November 10, 2020

https://www.sciencedaily.com/releases/2020/11/201110133222.htm

Drop in pandemic carbon dioxide emissions previews world of electric vehicles

In the six weeks after the San Francisco Bay Area instituted the nation's first shelter-in-place mandate in response to the growing COVID-19 pandemic, regional carbon dioxide emissions dropped by 25%, almost all of it due to a nearly 50% drop in road traffic, according to new study from the University of California, Berkeley.

Though emissions have steadily increased since then, the dramatic response to a sharp cut-off in vehicular fossil fuel burning shows how effectively a move toward broad use of electric-powered vehicles would reduce the major greenhouse gas responsible for climate change and global warming.The data come from a network of carbon dioxide sensors set up around the Bay Area by UC Berkeley scientists over the past eight years -- a network that is already being replicated in several cities around the world. Glasgow, Scotland, will announce tomorrow (Nov. 10) that it plans to install 25 of these monitors within the next year in time for the Nov. 1, 2021, start of the United Nations Climate Change Conference in that city."This is what it would look like for COCohen is participating in a webinar about the project tomorrow, 8-11:45 a.m. PST, along with Mary Nichols, chair of the California Air Resources Board, and Glasgow and Scottish leaders. He and his colleagues reported the results of their Bay Area study in a paper posted online Oct. 30 in the journal The state of California has already banned the sale of gas-powered vehicles by 2035 and has set a goal to reduce state carbon dioxide emissions by about 3% each year for the next 10 years. A statewide network like the small-scale network Cohen set up -- the Berkeley Environmental Air-quality & CO"We are making the case that this is the way to track urban COCohen noted that no government agency routinely tracks urban carbon dioxide emissions on the ground. The federal Environmental Protection Agency (EPA) is responsible for tracking such things as ozone, NOx and particulates, but not CO"It is almost silly that we weren't measuring CONearly a decade ago, Cohen set out to find a way to measure pollutants, including carbon dioxide, inexpensively enough to deploy on the neighborhood level. Per site, EPA stations can cost around $200,000, and they don't even come with COUsing new technology several notches better than the carbon monoxide and carbon dioxide sensors in our homes, he is now able to build -- for $8,000 -- a package the size of a shoebox that every 5 seconds record levels of COOver the past five years, he has deployed 72 of these instrument packages around the Bay Area as part of BEACOCohen's goal is to provide governments and policymakers with the feedback they need as they try to reduce pollutants and greenhouse gases. By placing them regularly throughout the area, he also hopes to show how reducing pollutants affects every community, especially lower-income communities that suffer too often from the unhealthiest air along freeway corridors and near power plants or refineries."From an environmental justice perspective, the question is, 'If we control COCap and trade -- a government regulatory program common in Europe, China and Canada and employed in 10 U.S. states, including California -- is a way of encouraging companies to reduce their carbon dioxide emissions. Specific companies are given a limit, or cap, on the amount of COToday, many cities also have climate action plans, yet they lack the data to monitor their success, Cohen said. Carbon dioxide levels around the globe are measured by NASA's Orbiting Carbon Observatory satellites and Japan's Greenhouse Gases Observing Satellites, but only on a regional level, not city by city."Our goal is to give people data to support what they are doing, so they can make judgements about what works effectively," Cohen said.On March 16, six counties in the Bay Area became the first region in the U.S. to tell non-essential employees to stay home to stop the spread of COVID-19. Cohen saw this as an opportunity to see what happens when the use of gas-fueled cars plummets.Tapping measurements from the BEACON network, Cohen and his colleagues compared the six weeks before shelter-in-place -- Feb. 2 through March 15 -- with a six-week period afterward, March 22 through May 2. Thirty-five of the sensors were operational throughout that time. The team corrected for the substantial uptake of COThe team found the greatest reduction in CODuring normal times, there is a large bump in COSuch data are not available from other monitoring systems, though a citizen science network, Purple Air, sells home air quality sensors for $250 or more that measure particulates, like smoke or dust, which have been shown to increase the risk of respiratory illnesses and cardiovascular disease. Carbon dioxide emissions, on the other hand, are estimated from the amount of fuel consumed by human activity.A recent study used such estimates of human activity to document that, during the pandemic, cities around the world saw a drop in CONetworks like BEACO"Here we would have a direct measure," Cohen said. "Going forward, we expect that direct observations of COCohen's coauthors are Alexander Turner, now at the University of Washington in Seattle; Jinsol Kim, Helen Fitzmaurice, Catherine Newman, Kevin Worthington, Katherine Chan, Paul Wooldridge of UC Berkeley; and Philipp Kohler and Christian Frankenberg of the California Institute of Technology in Pasadena. The UC Berkeley work was funded, in part, by the Koret Foundation.

Pollution

November 9, 2020

https://www.sciencedaily.com/releases/2020/11/201109074111.htm

More green spaces can help boost air quality, reduce heart disease deaths

Green spaces -- trees, shrubs and grasses -- can improve air quality and may lower heart disease deaths, according to preliminary research to be presented at the American Heart Association's Scientific Sessions 2020. The meeting will be held virtually, Friday, November 13 -- Tuesday, November 17, 2020, and is a premier global exchange of the latest scientific advancements, research and evidence-based clinical practice updates in cardiovascular science for health care worldwide.

"We found that both increased greenness and increased air quality were associated with fewer deaths from heart disease," said William Aitken, M.D., a cardiology fellow with the University of Miami Miller School of Medicine and UM/Jackson Memorial Hospital in Miami, Florida.Greenness is a measure of vegetative presence (trees, shrubs, grass) often assessed by NASA imaging of the Earth and other methods. Here, researchers used the Normalized Difference Vegetative Index (NDVI), which measures wavelengths of visible and near-infrared sunlight reflected from the Earth's surface via NASA satellite imagery. A higher index corresponds to more healthy vegetation, as chlorophyll typically absorbs visible light and reflects near-infrared light.In this cross-sectional study conducted using national air quality, greenness, CVD and census data from 2014-2015, researchers measured greenness by county across the United States and compared it to national disease death rates from the Centers for Disease Control and Prevention's Interactive Atlas of Heart Disease. They also overlaid data from the Environmental Protection Agency's air quality measurements of particulate matter for each county and the Census Bureau's information on age, race, education and income by county.The analysis found:"We found that areas with better air quality have higher greenness, and that having higher greenness measures, in turn, is related to having a lower rate of deaths from heart disease," said Aitken, who collaborated on the research with University of Miami public health scientists."Given the potential cardiovascular benefits of higher greenness measures, it's important that dialogue about improved health and quality of life include environmental policies that support increasing greenness. Policymakers should support greenness through efforts that promote environmental justice through equitable access to green spaces, clean air and clean water, as well as minimizing exposure to environmental hazards," he added.The researchers hope their results encourage clinical trials using built environment interventions (e.g., tree planting to increase vegetative presence and greenness) to improve cardiovascular health. "We will be performing a longitudinal study in Miami to assess if changes in neighborhood greenness over time are associated with changes in cardiovascular disease," Aitken said.The main limitations of this study include that it was cross-sectional and used a total of combined cardiovascular disease death rates.

Pollution

November 7, 2020

https://www.sciencedaily.com/releases/2020/11/201107133922.htm

Rivers melt Arctic ice, warming air and ocean

A new study shows that increased heat from Arctic rivers is melting sea ice in the Arctic Ocean and warming the atmosphere.

The study published this week in According to the research, major Arctic rivers contribute significantly more heat to the Arctic Ocean than they did in 1980. River heat is responsible for up to 10% of the total sea ice loss that occurred from 1980 to 2015 over the shelf region of the Arctic Ocean. That melt is equivalent to about 120,000 square miles of 1-meter thick ice."If Alaska were covered by 1-meter thick ice, 20% of Alaska would be gone," explained Igor Polyakov, co-author and oceanographer at the University of Alaska Fairbanks' International Arctic Research Center and Finnish Meteorological Institute.Rivers have the greatest impact during spring breakup. The warming water dumps into the ice-covered Arctic Ocean and spreads below the ice, decaying it. Once the sea ice melts, the warm water begins heating the atmosphere.The research found that much more river heat energy enters the atmosphere than melts ice or heats the ocean. Since air is mobile, this means river heat can affect areas of the Arctic far from river deltas.The impacts were most pronounced in the Siberian Arctic, where several large rivers flow onto the relatively shallow shelf region extending nearly 1,000 miles offshore. Canada's Mackenzie River is the only river large enough to contribute substantially to sea ice melt near Alaska, but the state's smaller rivers are also a source of heat.Polyakov expects that rising global air temperatures will continue to warm Arctic rivers in the future. As rivers heat up, more heat will flow into the Arctic Ocean, melting more sea ice and accelerating Arctic warming.Rivers are just one of many heat sources now warming the Arctic Ocean. The entire Arctic system is in an extremely anomalous state as global air temperatures rise and warm Atlantic and Pacific water enters the region, decaying sea ice even in the middle of winter. All these components work together, causing positive feedback loops that speed up warming in the Arctic."It's very alarming because all these changes are accelerating," said Polyakov. "The rapid changes are just incredible in the last decade or so."Authors of the paper include Hotaek Park, Eiji Watanabe, Youngwook Kim, Igor Polyakov, Kazuhiro Oshima, Xiangdong Zhang, John S. Kimball and Daqing Yang.

Pollution

November 7, 2020

https://www.sciencedaily.com/releases/2020/11/201107133917.htm

Study projects more rainfall in Florida during flooding season

A new study by researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science projects an increase in Florida's late summertime rainfall with rising Atlantic Ocean temperatures.

Scientists have known for years that Florida receives more rainfall in decades when North Atlantic waters are warmer than average, but the UM research team wanted to learn more about this interaction to help communities prepare for a wetter future. This study showed that ocean temperatures are most influential on Florida precipitation in late summer, during the region's highest high tide events.The researchers used a suite of climate models to show that the link between ocean temperatures and rainfall only develops as a result of human influences on the climate system, such as greenhouse gas emissions and industrial pollution."We know that humans are continuing to make North Atlantic waters warmer, so we expect an increase in late summer rainfall in Florida in the future," said Jeremy Klavans, a PhD student at the UM Rosenstiel School and lead author of the study.The study, titled "Identifying the Externally?forced Atlantic Multidecadal Variability Signal through Florida Rainfall" was published in the early online edition of the American Geophysical Union's journal

Pollution

November 6, 2020

https://www.sciencedaily.com/releases/2020/11/201106093018.htm

Plastics and rising CO2 levels could pose combined threat to marine environment

The combined environmental threat of plastic pollution and ocean acidification are having significant impacts on species living in our oceans, according to new research.

An international team of scientists found that after three weeks of being submerged in the ocean, the bacterial diversity on plastic bottles was twice as great as on samples collected from the surrounding seawater.However, in areas of elevated carbon dioxide, a large number of taxonomic groups -- including bacteria that play an important role in carbon cycling -- were negatively impacted.Conversely, other species -- including those have previously been shown to thrive in areas of high ocean plastics and to potentially cause disease on coral reefs -- were enriched by it.The research also showed that while many groups of bacteria were shared between plastic, free-living and particle-associated samples, almost 350 were found uniquely on plastics.Writing in the journal However, their results highlight that environmental conditions and local ecological processes will play an important role in determining its broader impact over the coming decades.The study was led by the University of Tsukuba (Japan) and the University of Plymouth (UK), in collaboration with Keimyung University (Korea), Kyungpook National University (Korea) and Nanjing University (China).Scientists submerged a number of plastic bottles in seas off the Japanese Island of Shikine, a region known for its COThey then used a combination of DNA sequencing and statistical techniques to analyse how bacteria colonise the plastic in comparison to the surrounding natural environment, and whether the increased COLead author Dr Ben Harvey, Assistant Professor at the University of Tsukuba's Shimoda Marine Research Center and a graduate of the BSc (Hons) Ocean Science programme in Plymouth, said: "Discarded plastic drinking bottles have become a common sight in our oceans and we were expecting to see them being colonised by different types of bacteria. We also predicted that raised COResearchers from Tsukuba, Plymouth and other collaborators have published several studies over the past decade showing the threats posed by ocean acidification in terms of habitat degradation and a loss of biodiversity.It is also the latest research by the University of Plymouth into plastics, with it being awarded a Queen's Anniversary Prize for Higher and Further Education in 2020 for its ground-breaking research and policy impact on microplastics pollution in the oceans.Jason Hall-Spencer, Professor of Marine Biology at the University of Plymouth and senior author on the study, added: "Up to 13 million tons of plastics from land end up in the oceans each year and they have been shown to affect all types and sizes of marine species. Combine that with rising CO

Pollution

November 5, 2020

https://www.sciencedaily.com/releases/2020/11/201105113017.htm

From hard to soft: Making sponges from mussel shells

Scientists have discovered a spongy form of calcium carbonate (CaCO3), a material found in limestone, chalk, marble, and the shells of mussels and other shellfish. While most forms of calcium carbonate are hard minerals, this new form is soft and absorbent. The researchers, reporting November 5 in the journal

"The local aquaculture industry here on the east coast of Canada got in touch and told us they were going to start growing more mussels in the ocean and producing more waste, and they asked us if there could be some use for it," says senior author Francesca Kerton, a professor of chemistry at Memorial University Newfoundland. "I hadn't really thought about inorganic materials in nature, so it was really a desire to use a food waste product rather than mining or drilling for minerals."While there are many industrial applications of calcium carbonate already, the research team discovered this spongey material by accident while exploring ways to make a less-corrosive de-icer for vehicles and roads. When they combined ground up mussel shells with acetic acid -- the chemical found in vinegar -- a strange, white spongey material emerged in the solution overnight."We thought somebody was playing a joke on us, putting bits of filter paper or something into the solution, because it didn't look like anything that we put in there," says Kerton. "So we scooped out some of the material and ran X-ray diffraction on it, and that told us it was calcite."Calcite is one of several naturally occurring forms of calcium carbonate. The researchers concluded that the material was formed from extra calcium carbonate that didn't react completely with the acetic acid. They also tested how well the substance could absorb oils and dyes, wondering if it could have applications in marine pollution cleanup. While they found that it was highly absorbent, they have not yet found a practical way to produce enough of the material to be used for large-scale cleaning projects."We did think it was kind of neat that we could possibly take material from an organism that grows in the sea and treat pollution in the ocean," says Kerton. "The fact that we could absorb oil as well as other materials that have been used was pretty exciting, but the scalability and cost of making this sponge will limit that application."So, while the researchers do not see this substance cleaning the ocean in the immediate future, that doesn't mean it's useless. The team now hopes to explore biomedical applications that would use much smaller amounts of the material."We've got lots of ideas for the future in terms of where it could be used. We're interested in whether it can take up drugs or active pharmaceutical ingredients or help control acid in the body," says Kerton. "Biological medicine might be the area where this is going to make the most impact."

Pollution

November 5, 2020

https://www.sciencedaily.com/releases/2020/11/201105113014.htm

Light pollution at night severely disrupts the reproductive cycle of corals

The daily light-dark cycle arising from the earth's rotation is centrally important to biology. Marine organisms, particularly coral reefs, rely on natural light cycles of sunlight and moonlight to regulate various physiological, biological and behavioral processes.

Artificial light produced by powerful street lamps, billboards, sports and industrial facilities, hotels, and office buildings effectively extends the day for work and leisure activities. But while artificial light at night (ALAN) is one of the most important human technological advances, the alteration of natural light cycles has many undesirable effects on the earth's ecosystems. These include skyglow, light trespass, glare, and over-illumination, collectively referred to as light pollution.Due to the high rate of urban development in marine coastal areas around the world, light pollution could further threaten coral communities' populations, which are already under severe degradation. A new study led by researchers from Bar-Ilan University in Israel demonstrates how light pollution is negatively impacting the reproductive cycle of two coral species.The coral reproductive cycle (the development of sperm and eggs) is controlled by a biological rhythm a few months during the year in harmony with natural environmental conditions. At the conclusion gametes (sperm and eggs) are released into the water for external fertilization. The mechanism that leads to synchronized spawning is thought to be controlled by both an exogenous (i.e., environmental) and endogenous apparatus (i.e., biological clock). Successful gamete production and fertilization, development of viable offspring, and survival of new coral recruits are possibly the most important processes for replenishing degraded reefs. Moreover, sexual reproduction maintains coral populations and supports evolutionary processes which may enhance fitness.For this study, just published in the journal For three months the LED lamps were activated every day from sundown until sunrise. The control groups were exposed to the same conditions as the experimental colonies (natural solar light, moonlight phases) but without supplemental light at night. Chlorophyll fluorescence yield was assessed on a monthly basis as an indicator of colony health.The results clearly showed that light pollution caused delayed gametogenesis and unsynchronized gamete release, emphasizing the importance of natural periodic illumination, both solar and lunar, as a critical factor in cueing spawning synchronicity and the gametogenic process. "Both key coral species were affected by ecological light pollution. They exhibited asynchrony in the reproductive state which was reflected in the number of oocytes per polyp, gametogenesis, and gamete maturation," says the study's lead author Prof. Oren Levy, of the Mina and Everard Goodman Faculty of Life Sciences at Bar-Ilan University. "This was further reflected at the population level where only corals exposed to natural light cycles succeeded in spawning synchronization. Light treatment with both cold and warm LED's had a similar impact on the gametogenesis cycle," added Levy. Levy led the Bar-Ilan study with the participation of the Interuniversity Institute for Marine Sciences in Eilat and Tel Aviv University team members Inbal Ayalon and Dr. Yaeli Rosenberg, and in collaboration with team leader Patrick Cabaitan, from The Marine Science Institute at the University of the Philippines, and light pollution specialists Dr. Christopher Kyba and Dr. Helga Kuechly from the German Research Centre for Geosciences GFZ.To shed light on how relevant their findings are on a worldwide scale, the researchers created a first-of-its-kind global map that highlights areas most threatened by ALAN including the Caribbean Sea and the Pacific and Indian Oceans. One striking example is the Gulf of Aqaba/Eilat in the northern Red Sea, where considerable urban lighting is present close to shore. Here, the least affected area is 47% brighter than a natural night sky, and this rises to a maximum of 60 times brighter.With the global transition towards LED lighting, which tends to have higher emissions in the blue spectrum, more near shore coral reefs could be affected by artificial light, as blue light penetrates deeper into the water. This spectral shift is expected to be amplified by the current rapid population growth in coastal regions. Levy and team's results demonstrate that artificial light must be considered in conservation plans for coral reefs near areas of human activity and their light pollution impact assessment can help incorporate an important variable in coral reef conservation planning.In follow-up research Levy hopes to determine whether there are corals more adapted to light pollution and, if so, what mechanism underlies their resilience.

Pollution

November 5, 2020

https://www.sciencedaily.com/releases/2020/11/201105112938.htm

Metal pollution in British waters may be threatening scallops, study reveals

Metal pollution from historic mining appears to be weakening scallop shells and threatening marine ecosystems in an area off the coast of the Isle of Man, a major new study suggests.

The research, led by an interdisciplinary team at the University of York, suggests that the contamination of seabed sediments with zinc, lead and copper from the mining of these metals, which peaked on the island in the late 19th century, is causing the shells of king scallops to become significantly more brittle.The thinning and weakening of shells threatens the species by leaving them more exposed to the crushing claws of crabs and lobsters, and, in turn, threatens the marine ecosystem because of the important functions, such as water filtration, that molluscs like scallops carry out.Given that metal contamination is common in many coastal areas around the world, the researchers are concerned that other species of marine mollusc like mussels, oysters and clams, which together provide more than a quarter of the world's seafood, may be similarly affected.The current consensus on acceptable levels of metal pollution should be revised, the researchers say, as evidence of damage to scallop shells was present even in areas with metal contamination levels currently not thought to cause significant damage to the marine environment.Lead author of the study, Dr Bryce Stewart from the Department of Environment and Geography at the University of York, said: "The fact that comparably low levels of heavy metal contaminations appear to affect shell structure and strength in such a potent way represents a challenge to marine species management and conservation strategies. This is particularly true given that the effects we observed are likely to be amplified in the future by ongoing human activities and climate change."The potential long-term impact of anthropogenic metal pollution on marine organisms, as shown in our work, is remarkable since the last major mine on the Isle of Man closed in 1908."Over a period of over 13 years, the researchers compared scallops collected from six areas of the Irish Sea around the Isle of Man. Most scallops exhibited perfectly normal shell growth and strength. However, in one area off Laxey -- known to be contaminated with metal pollution, the shells were significantly weaker.Structural analysis of shells by physicists at the University of York revealed that Laxey scallops had significantly weaker shells and a disrupted shell structure. Lethal damage rates in scallop catches from Laxey were twice as high as those at uncontaminated areas.Joint corresponding author Professor Roland Kröger, from the Department of Physics at the University of York, said: "We analysed the shell structure of the scallops with cutting-edge microscopy techniques and discovered that shells from Laxey were thinner and exhibited a pronounced mineralisation disruption parallel to the shell surface within the central region of both the top and bottom valves."Our data suggest that these disruptions caused reduced fracture strength and therefore could increase mortality."It is not clear exactly how metal bearing sediments may be affecting the shell formation process. Metals could be incorporated into shells replacing calcium during the biomineralization process or they may modify the activity of proteins during the crystallisation process and disrupt shell growth."The researchers looked at a wide range of alternative explanations for the impact on scallop shells but found no other environmental factors that could explain their results.Dr Stewart added: "While the scallops are still perfectly safe to eat, we believe our results provide a compelling case that metal contamination is playing an important role in the development of thinner and weaker shells at Laxey, and therefore the observed high damage rates."The shell characteristics of bivalve molluscs such as clams, oysters, mussels and scallops could potentially function as a good bellwether for the scientific community in assessments of how pollutants are affecting biological organisms."

Pollution

November 5, 2020

https://www.sciencedaily.com/releases/2020/11/201105083719.htm

The burning question of Bonfire Night pollution

Bonfire Night celebrations contaminate our air with hugely elevated amounts of soot, scientists have found.

Researchers from the University of Leeds were monitoring air quality to determine whether soot created by fires and fireworks, known as black carbon, could help to create ice in clouds.They found soot in the atmosphere around Guy Fawkes Night events was around 100 times its normal level.Ice occurs naturally in clouds, but tiny particles of desert dust, soil dust, fungus and bacteria swept high into the air can cause supercooled water droplets in clouds to freeze around them. High concentrations of these ice-nucleating particles can cause clouds to freeze, potentially impacting the earth's climate.The team carried out experiments on 5 November 2016 into the early hours of the following day, and in 2017 from November 4 and 5, filtering the air with samples taken hourly. Equipment was set up on the balcony of the School of Earth and Environment building, 15m from ground level and more than 0.5 km from any individual bonfires or firework displays, to give a representative view of the air quality across the city.The filters were washed and the liquid subjected to different temperatures to replicate atmospheric conditions.The researchers discovered black carbon produced on Bonfire Night did not act as ice nucleating particles -- but they did not expect to see such high levels of the polluting matter in the atmosphere.Black carbon particles are so small, they can penetrate deep into the lungs and cause irritation. Long term exposure can cause harmful effects on the heart and lungs and contributes to millions of deaths worldwide each year.The paper, A major combustion aerosol event had a negligible impact on the atmospheric ice-nucleating particle population, has been published in The research was funded by the European Research Council.Lead author Michael Adams, Research Fellow in Atmospheric Ice Nucleation, said: "Our measurements showed that whilst pollution emitted on Bonfire Night shouldn't have any effect on whether clouds are liquid or ice, the elevated concentrations of soot and other pollutants in the atmosphere should be a warning to those with pre-existing health conditions, as the aerosol particles are in the size range where they can enter the lungs and cause problems."Research supervisor Benjamin Murray, Professor of Atmospheric Science in Leeds' School of Earth and Environment, said: "Bonfire Night is a massive pollution event across the UK. People with existing health problems, such as heart and lung conditions, are at increased risk.""The impact on clouds and climate was not clear. The good news is that Bonfire Night does not impact the formation of ice in supercooled cloud droplets. But, we know that BC causes climate warming in other ways."I was surprised to see levels of black carbon so persistently high for so long on multiple nights. It was striking how poor air quality was on Bonfire Night."Weather conditions can affect how long the particles remain in the air. The team found the pollution was flushed out of the city within a few hours during the 2016 experiment, due to a brisk wind from the north.But in 2017 the air was relatively still and the pollution lingered into the next day.While providing insight into the levels of black carbon emitted on Bonfire Night, the team's discoveries have also contributed to the understanding of different sources of ice nucleating particles -- a key research area in climate science.Prof Murray said: "Clouds containing supercooled water and ice are first order importance for climate. Vast cloud systems made of a mixture of ice and water over the world's oceans buffer the warming effect of CO"But the buffering capacity depends on how much ice is in them, which in turn depends on the concentration and distribution of ice nucleating particles."We found that aerosol particles emitted during the celebration are not as effective at nucleating ice as aerosol particle already present in the atmosphere."We conclude that aerosol particles emitted from combustion processes such as those observed on Bonfire Night are not an important source of ice nucleating particles."

Pollution

November 4, 2020

https://www.sciencedaily.com/releases/2020/11/201104143619.htm

'Environmentally-friendly' tableware harms marine animals

A new Tel Aviv University study compares the effects of two types of disposable dishes on the marine environment -- regular plastic disposable dishes and more expensive bioplastic disposable dishes certified by various international organizations -- and determines that the bioplastic dishes had a similar effect on marine animals as regular plastic dishes. Moreover, the study finds that bioplastic does not degrade rapidly in the marine environment.

The research was led by research student Guillermo Anderson and Prof. Noa Shenkar of the School of Zoology at the George S. Wise Faculty of Life Sciences and the Steinhardt Museum of Natural History, Israel National Center for Biodiversity Studies, Tel Aviv University. The study was published online on August 20, 2020, in the journal "People buy expensive disposable dishes and utensils with the special bioplastic standard seal of compliance on the assumption that they are being environmentally responsible," Prof. Shenkar says. "Our study proves that while this may be good for their conscience, it can still damage the environment."Environmental pollution caused by plastics in general and at sea in particular is a well-known crisis. According to various assessments, some 350 million tons of plastic goods are produced every single year, half of which is disposable dishes and utensils thrown away after a single use. Plastic is a very durable polymer made of chemicals derived from fossil fuels. Marine animals ingest plastic microparticles containing toxic additives that are integral to these harmful microparticles."In recent decades, substances called 'bioplastics' came on the market," Anderson explains. "Bioplastics are made of natural, renewable materials, and biodegrade relatively fast under certain conditions. Disposable dishes and utensils made of bioplastics were granted various international standard seals and are marketed to consumers as environmentally friendly. We wanted to test the supposedly environmentally friendly disposable dishes to see if they do, in fact, meet expectations."The study compared disposable cups made of regular plastic and bioplastic and their effects on ascidians, a type of a marine invertebrate; examined the extent, if any, to which these marine invertebrates were capable of digesting particles of the regular plastics and bioplastics; then observed the recruitment of marine organisms to the materials.At least in the short term, both types of plastic have a similar detrimental effect, Prof. Shenkar says. "Bioplastics are made of natural materials and, in that sense, they are more beneficial environmentally speaking. But they may also contain toxins just like regular plastic dishes and they do not biodegrade quickly in the aquatic habitat. In fact, the standard appearing on the label is dated. It doesn't refer at all to different kinds of plastic additives and speaks of biodegrading within 180 days, but that is specifically under conditions available only in industrial composting settings."

Pollution

November 4, 2020

https://www.sciencedaily.com/releases/2020/11/201104083014.htm

Brown carbon 'tarballs' detected in Himalayan atmosphere

Some people refer to the Himalaya-Tibetan Plateau as the "third pole" because the region has the largest reserve of glacial snow and ice outside of the north and south poles. The glaciers, which are extremely sensitive to climate change and human influence, have been retreating over the past decade. Now, researchers reporting in ACS'

Burning biomass or fossil fuels releases light-absorbing, carbonaceous particles that can deposit on snow and ice, possibly hastening the melting of glaciers. Previous research has shown that one type of particle, called black carbon, can be transported long distances by wind to the Himalayan atmosphere. But much less is known about the presence of brown carbon, a particle that can form tarballs -- small, viscous spheres consisting of carbon, oxygen and small amounts of nitrogen, sulfur and potassium. Weijun Li and colleagues wanted to see what types of individual aerosol particles were present in air samples taken at a remote, high-altitude research station on the northern slope of the Himalayas.Using electron microscopy, the researchers unexpectedly found that about 28% of the thousands of particles in the air samples from the Himalayan research station were tarballs, and the percentage increased on days with elevated levels of pollution. Analyzing wind patterns and satellite data revealed that a dense array of active fire spots, corresponding to large-scale wheat-residue burning on the Indo-Gangetic Plain, occurred along the pathways of air masses that reached the Himalayan research station during sampling. Through modeling calculations, the team estimated that tarballs deposited on glacial surfaces could contribute a significant warming effect. As a result, future climate models should consider the long-range transport of tarballs to the Himalayas, the researchers say.

Pollution

November 2, 2020

https://www.sciencedaily.com/releases/2020/11/201102162653.htm

Self-watering soil could transform farming

 A new type of soil created by engineers at The University of Texas at Austin can pull water from the air and distribute it to plants, potentially expanding the map of farmable land around the globe to previously inhospitable places and reducing water use in agriculture at a time of growing droughts.

As published in "Enabling free-standing agriculture in areas where it's hard to build up irrigation and power systems is crucial to liberating crop farming from the complex water supply chain as resources become increasingly scarce," said Guihua Yu, associate professor of materials science in the Walker Department of Mechanical Engineering.Each gram of soil can extract approximately 3-4 grams of water. Depending on the crops, approximately 0.1 to 1 kilogram of the soil can provide enough water to irrigate about a square meter of farmland.The gels in the soil pull water out of the air during cooler, more humid periods at night. Solar heat during the day activates the water-containing gels to release their contents into soil.The team ran experiments on the roof of the Cockrell School's Engineering Teaching Center building at UT Austin to test the soil. They found that the hydrogel soil was able to retain water better than sandy soils found in dry areas, and it needed far less water to grow plants.During a four-week experiment, the team found that its soil retained approximately 40% of the water quantity it started with. In contrast, the sandy soil had only 20% of its water left after just one week.In another experiment, the team planted radishes in both types of soil. The radishes in the hydrogel soil all survived a 14-day period without any irrigation beyond an initial round to make sure the plants took hold. Radishes in the sandy soil were irrigated several times during the first four days of the experiment. None of the radishes in the sandy soil survived more than two days after the initial irrigation period."Most soil is good enough to support the growth of plants," said Fei Zhao, a postdoctoral researcher in Yu's research group who led the study with Xingyi Zhou and Panpan Zhang. "It's the water that is the main limitation, so that is why we wanted to develop a soil that can harvest water from the ambient air."The water-harvesting soil is the first big application of technology that Yu's group has been working on for more than two years. Last year, the team developed the capability to use gel-polymer hybrid materials that work like "super sponges," extracting large amounts of water from the ambient air, cleaning it and quickly releasing it using solar energy.The researchers envision several other applications of the technology. It could potentially be used for cooling solar panels and data centers. It could expand access to drinking water, either through individual systems for households or larger systems for big groups such as workers or soldiers.

Pollution

November 2, 2020

https://www.sciencedaily.com/releases/2020/11/201102150845.htm

Flying through wildfire smoke plumes could improve smoke forecasts

Wildfires burning in the West affect not only the areas burned, but the wider regions covered by smoke. Recent years have seen hazy skies and hazardous air quality become regular features of the late summer weather.

Many factors are causing Western wildfires to grow bigger and to generate larger, longer-lasting smoke plumes that can stretch across the continent. An analysis led by the University of Washington looks at the most detailed observations to date from the interiors of West Coast wildfire smoke plumes.The multi-institutional team tracked and flew through wildfire plumes from the source to collect data on how the chemical composition of smoke changed over time. A resulting paper, published Nov. 2 in the The new results could significantly change the estimate for particles in staler smoke, which could be the difference between "moderate" and "unhealthy" air quality in regions downwind of the fire."Wildfires are getting larger and more frequent, and smoke is becoming a more important contributor to overall air pollution," said lead author Joel Thornton, a UW professor of atmospheric sciences. "We really targeted the smoke plumes close to the source to try better understand what's emitted and then how it can transform as it goes downwind."Knowing how newly generated wildfire smoke transitions to stale, dissipated smoke could lead to better forecasts for air quality. Communities can use those forecasts to prepare by moving outdoor activities inside or rescheduling in cases where the air will be unsafe to be outdoors, as well as limiting other polluting activities such as wood-burning fires."There are two aspects that go into smoke forecasts," said first author Brett Palm, a UW postdoctoral researcher in atmospheric sciences. "One is just where is the smoke plume going to go, based on dynamics of how air moves in the atmosphere. But the other question is: How much smoke gets transported -- how far downwind is air quality going to be bad? That's the question our work helps to address."When trees, grass and foliage burns at high temperatures they generate soot, or black carbon, as well as organic particles and vapors, called organic aerosols, that are more reactive than soot. Fires can also produce "brown carbon" aerosol, a less-well-understood form of organic aerosol that gives skies a brownish haze.Once in the air, the organic aerosols can react with oxygen or other molecules already in the atmosphere to form new chemical compounds. Air temperature, sunlight and concentration of smoke affect these reactions and thus alter the properties of the older smoke plume.The multi-institutional team measured these reactions by flying through wildfire plumes in July and August 2018 as part of WE-CAN, or the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption and Nitrogen field campaign led by Colorado State University.Research flights from Boise, Idaho, used a C-130 research aircraft to observe the smoke. The study flew through levels of 2,000 micrograms per cubic meter, or about seven times the worst air experienced in Seattle this summer. Seals on the aircraft kept the air inside the craft much cleaner, though researchers said it was like flying through campfire smoke."We tried to find a nice, organized plume where we could start as close to the fire as possible," Palm said. "Then using the wind speed we would try to sample the same air on subsequent transects as it was traveling downwind."The analysis in the new paper focused on nine well-defined smoke plumes generated by the Taylor Creek Fire in southwestern Oregon, the Bear Trap fire in Utah, the Goldstone fire in Montana, the South Sugarloaf fire in Nevada, and the Sharps, Kiwah, Beaver Creek and Rabbit Foot wildfires in Idaho."You can't really reproduce large wildfires in a laboratory," Palm said. "In general, we tried to sample the smoke as it was aging to investigate the chemistry, the physical transformations that are happening."The researchers found that one class of wildfire emissions, phenols, make up only 4% of the burned material but about one-third of the light-absorbing "brown carbon" molecules in fresh smoke. They found evidence of complex transformations within the plume: Vapors are condensing into particles, but at the same time and almost the same rate, particulate components are evaporating back into gases. The balance determines how much particulate matter survives, and thus the air quality, as the plume travels downwind."One of the interesting aspects was illustrating just how dynamic the smoke is," Palm said. "With competing processes, previous measurements made it look like nothing was changing. But with our measurements we could really illustrate the dynamic nature of the smoke."The researchers found that these changes to chemical composition happen faster than expected. As soon as the smoke is in the air, even as it's moving and dissipating, it starts to evaporate and react with the surrounding gases in the atmosphere."When smoke plumes are fresh, they're almost like a low-grade extension of a fire, because there's so much chemical activity going on in those first few hours," Thornton said.The authors also performed a set of 2019 experiments inside a research chamber in Boulder, Colorado, that looked at how the ingredients in smoke react in daytime and nighttime conditions. Wildfires tend to grow in the afternoon winds when sunlight speeds up chemical reactions, then die down and smolder at night. But very large wildfires can continue to blaze overnight when darker skies change the chemistry.Understanding the composition of the smoke could also improve weather forecasts, because smoke cools the air underneath and can even change wind patterns."In Seattle, there are some thoughts that the smoke changed the weather," Thornton said. "Those kinds of feedbacks with the smoke interacting with the sunlight are really interesting going forward."

Pollution

October 30, 2020

https://www.sciencedaily.com/releases/2020/10/201030142125.htm

New study reveals United States a top source of plastic pollution in coastal environments

A study published today in the journal

Using plastic waste generation data from 2016 -- the latest available global numbers -- scientists from Sea Education Association, DSM Environmental Services, University of Georgia, and Ocean Conservancy calculated that more than half of all plastics collected for recycling (1.99 million metric tons of 3.91 million metric tons collected) in the United States were shipped abroad. Of this, 88% of exports went to countries struggling to effectively manage, recycle, or dispose of plastics; and between 15-25% was low-value or contaminated, meaning it was effectively unrecyclable. Taking these factors into account, the researchers estimated that up to 1 million metric tons of U.S.-generated plastic waste ended up polluting the environment beyond its own borders."For years, so much of the plastic we have put into the blue bin has been exported for recycling to countries that struggle to manage their own waste, let alone the vast amounts delivered from the United States," said lead author Dr. Kara Lavender Law, research professor of oceanography at Sea Education Association. "And when you consider how much of our plastic waste isn't actually recyclable because it is low-value, contaminated or difficult to process, it's not surprising that a lot of it ends up polluting the environment."Using 2016 data, the paper also estimated that 2-3% of all plastic waste generated in the U.S. -- between 0.91 and 1.25 million metric tons -- was either littered or illegally dumped into the environment domestically. Combined with waste exports, this means the United States contributed up to 2.25 million metric tons of plastics into the environment. Of this, up to 1.5 million metric tons of plastics ended up in coastal environments (within 50 km of a coastline), where proximity to the shore increases the likelihood of plastics entering the ocean by wind or through waterways. This ranks the United States as high as third globally in contributing to coastal plastic pollution."The United States generates the most plastic waste of any other country in the world, but rather than looking the problem in the eye, we have outsourced it to developing countries and become a top contributor to the ocean plastics crisis," said Nick Mallos, senior director of Ocean Conservancy's Trash Free Seas® program and a co-author of the study. "The solution has to start at home. We need to create less, by cutting out unnecessary single-use plastics; we need to create better, by developing innovative new ways to package and deliver goods; and where plastics are inevitable, we need to drastically improve our recycling rates."The study noted that although the United States accounted for just 4% of the global population in 2016, it generated 17% of all plastic waste. On average, Americans generated nearly twice as much plastic waste per capita as residents of the EU."Previous research has provided global values for plastic input into the environment and coastal areas, but detailed analyses like this one are important for individual countries to further assess their contributions," said Dr. Jenna Jambeck, Distinguished Professor at the University of Georgia's College of Engineering and a co-author of the study. "In the case of the United States, it is critically important that we examine our own backyard and take responsibility for our global plastic footprint.""For some time, it has been cheaper for the United States to ship its recyclables abroad rather than handle them here at home, but that has come at great cost to our environment," said Natalie Starr, principal at DSM Environmental Services and a co-author of the study. "We need to change the math by investing in recycling technologies and collection programs, as well as accelerating research and development to improve the performance and drive down the costs of more sustainable plastics and packaging alternatives to address the current challenge."

Pollution

October 30, 2020

https://www.sciencedaily.com/releases/2020/10/201030111744.htm

Researchers devise new method to get the lead out

Commercially sold water filters do a good job of making sure any lead from residential water pipes does not make its way into water used for drinking or cooking.

Filters do not do a good job, however, of letting the user know how much lead was captured.Until now, when a researcher, public works department or an individual wanted to know how much lead was in tap water, there wasn't a great way to find out. Usually, a scientist would look at a one-liter sample taken from a faucet.Researchers in the McKelvey School of Engineering at Washington University in St. Louis have devised a new method that allows them to extract the lead from these "point-of-use" filters, providing a clearer picture of what's coming out of the faucet.And they can do it in less than an hour.Their research was published this past summer in the journal The problem with just collecting a one-liter sample is that "We don't know how long it was in contact with that lead pipe or if it just flowed through quickly. Everyone's water use patterns are different," said Daniel Giammar, the Walter E. Browne Professor of Environmental Engineering in the Department of Energy, Environmental & Chemical Engineering."Collecting a single liter is not a good way of assessing how much lead a resident would be exposed to if not using a filter," he said. "To do that, you'd need to see all that the person was drinking or using for cooking."A better method would be to collect the lead from a filter that had been in use long enough to provide an accurate picture of household water use. Most of the commercial filters for sale at any major retail store will last for about 100 gallons -- 40 times the amount of the typical water sample.The idea to use filters in this way isn't new, but it hasn't been done very efficiently, precisely because the filters do such a good job at holding onto the lead.Giammar said he had probably heard about this method previously, but a light went off after a conversation about indoor air quality. He had been talking to a professor at another institution who was monitoring indoor air quality using a box that sucked in air, collecting contaminants in a tube. The user can then remove the collection tube and send it to a lab to be analyzed."I said, 'Let's do what you're doing with air,'" pull water through a filter, collect contaminants and then analyze them. "Then we realized, they already make and sell these filters."Point-of-use filters are typically made of a block of activated carbon that appears solid, almost like a lump of coal. The water filters through tiny pores in the carbon; the carbon binds to the lead, trapping it before the water flows out of the faucet."If you want to take the lead out of the water, you need something that is really good at strongly holding on to it," which carbon is, Giammar said."So we had to hit it with something even stronger to pull that lead off."The solution? Acid.Working with senior Elizabeth Johnson, graduate student Weiyi Pan tried different methods, but ultimately discovered that slowly passing an acidic solution through the filter would liberate 100% of the lead.The entire process took about two liters of acid and about a half hour.In the near future, Giammar sees the filters being put to use for research, as opposed to being put in the trash."The customer has a filter because they want to remove lead from the water. The water utility or researcher wants to know how much lead is in the home's water over some average period of time," Giammar said. Even if the customer doesn't care, they've got this piece of data that usually they'd just throw away."We'd rather them send it to their utility service, or to us, and we can use it to get information."

Pollution

October 29, 2020

https://www.sciencedaily.com/releases/2020/10/201029135503.htm

Streetlights contribute less to nighttime light emissions in cities than expected

When satellites take pictures of Earth at night, how much of the light that they see comes from streetlights? A team of scientists from Germany, the USA, and Ireland have answered this question for the first time using the example of the U.S. city of Tucson, thanks to "smart city" lighting technology that allows cities to dim their lights. The result: only around 20 percent of the light in the satellite images of Tucson comes from streetlights. The study is published today in the journal

The team conducted an experiment by changing the brightness of streetlights in the city of Tucson, Arizona, USA, and observing how this changed how bright the city appeared from space. Dr. Christopher Kyba from the GFZ German Research Centre for Geosciences led the team that conducted the experiment, and said the work is important because it shows that smart city technologies can be used to perform city-scale experiments. "When sensors and control systems are installed throughout an entire city, it is possible to make a change in how the city works, and then measure the impact that change has on the environment, even from outer space," Kyba said.Over a period of 10 days in March and April of 2019, Tucson officials changed the brightness settings for about 14,000 of the city's 19,500 streetlights. Usually, most streetlights in Tucson start out at 90 per cent of their maximum possible illumination, and dim to 60 per cent at midnight. During the experiment, the city instead dimmed lights all the way down to 30 per cent on some nights, and brightened them up to 100 per cent on others. The city lights were observed by the US-operated Suomi National Polar-orbiting Partnership (NPP) satellite, which is famous for its global maps of light at night. The satellite took cloud-free images of Tucson on four nights during the test, and on two other nights with regular lighting after the test. By comparing the city brightness on the 6 different nights, the researchers found that on a normal night, only about 20 per cent of the light in satellite images of Tucson comes from streetlights.The results have important implications for sustainability, according to study co-author Dr. John Barentine from the International Dark-Sky Association. In a second experiment conducted at the same time, Barentine, Kyba and their co-authors measured the sky brightness over Tucson from the ground. They examined how varying the illuminance of street lamps affected the sky brightness, and showed that as with light emissions seen from space, most of the sky brightness over Tucson is also due to other sources. "Taken together, these studies show that in a city with well-designed streetlights, most of the light emissions and light pollution come from other lights," Barentine explaines, including light sources such as bright shop windows, lit signs and facades, or sport fields. The authors say that local and national governments therefore need to think about more than just street lighting when trying to reduce light pollution.According to the researchers, the difference in the streetlighting brightness on the different nights is barely perceptible to the people on the street, as our eyes quickly adapt to the light levels. They report that the city received no comments or complaints about the changed lighting during the test. There is also no evidence or suggestion that reducing lighting levels as part of the experiment had any adverse effect on public safety.Kyba is therefore excited by the idea of performing such experiments more regularly, and in other municipalities. "Instead of dimming lights to the same level late each night, a city could instead dim to 45% on even days and 55% on odd days," Kyba suggested. "City residents wouldn't notice any difference, but that way we could measure how the contribution of different light types is changing over time."

Pollution

October 28, 2020

https://www.sciencedaily.com/releases/2020/10/201028134032.htm

Tracing the source of illicit sand--can it be done?

If you've visited the beach recently, you might think sand is ubiquitous. But in construction uses, the perfect sand and gravel is not always an easy resource to come by. "Not all sand is equal in terms of what it can be used for," notes Zack Sickman, coauthor of a new study to be presented on Thursday at the Geological Society of America annual meeting. He says concrete aggregate needs sand with a certain size and angularity -- the kind that is considered "immature" and often, but not always, found in rivers.

The demand for sand has exploded since WWII. "The consumption of sand and gravel and crushed rock started accelerating [after the Second World War] as a result of all the construction and infrastructure development and urbanization that was happening in many areas," says Aurora Torres, coauthor of the study.Although construction in Europe and North America has slowed, Torres notes that developing nations are experiencing rapid urbanization, and with it, an increased need for resources. The projected amounts of sand and gravel will likely jump from 35 gigatons per year (2011 levels) to 82 gigatons per year by 2060.Sand mining, whether legal or illegal, has environmental and social impacts. Sand removal can affect agriculture, water quality, air pollution, sediment availability, and human health issues. While regulations can help lessen impacts, some of this extraction and transport is illegal and unmonitored. It's this illicit trade that the team is focusing on.The answer might be in the grains themselves. Sand is a strong forensic marker -- it reflects the unique rocks within a drainage basin and keeps the record from extraction to construction. "There's no reason why I couldn't go take a core of concrete of an existing skyscraper and take that same compositional signature and tie it back to a source," notes Sickmann.Being able to quickly determine if mined sand is from an illegal area is an important step in tamping down illicit sand trade. Sickmann says that it's possible to determine which river produced a truckload of sand, but "the real crux of the issue is finding the most effective way to use the method in a regulatory capacity."Sickmann and Torres want to find the most cost effective way to quickly and effectively fingerprint sand from different sources. They plan to start a proof-of-concept test on domestic (U.S.) sand first, where the sources and processing locations are well known. They and colleagues around the U.S. will collect concrete from home improvement stores and see if they can trace back the source of the sand. If they can successfully identify the catchment where the sand was sourced, they can move their methods to other global regions.The team thinks a quick sand fingerprinting method would be perfect for areas in Southeast and South Asia. "Not only are there areas of concern there with respect to illicit supply networks, the geology of Southeast Asia and South Asia is complex, and should provide a lot of leverage in distinguishing sand from different regional areas of concern," notes Sickmann. The more diverse the rocks are in a basin, the easier it is to distinguish where the sand originated from.Sand provenance identification is critical for reducing the impacts of illegal sand mining. "This is a very important issue," says Torres. "I see this as a valuable tool that will be that will complement other strategies that are being put in place to track and monitor these illicit supply networks."

Pollution

October 28, 2020

https://www.sciencedaily.com/releases/2020/10/201028101842.htm

SARS-CoV-2 outbreak investigation in meat processing plant suggests aerosol transmission in confined

The importance of maintaining high quality air flow to restrict transmission of SARS-CoV-2 in confined workspaces has been strongly indicated by the investigation of an outbreak of the virus at a German meat processing plant during May and June 2020. The study, published in

The study is relevant for many workplaces, but especially significant for the meat and fish processing industries that emerged early during the pandemic as hotspots for SARS-CoV-2 around the world. A combination of environmental conditions and operational practices with close proximity between many workers on production lines engaged in physically demanding tasks promoting heavy breathing, along with shared housing and transportation, all conspire to encourage viral transmission in such plants.Melanie Brinkmann from Technische Universität Braunschweig and Helmholtz Centre for Infection Research, Germany, Nicole Fischer from University Medical Center Hamburg-Eppendorf, Hamburg, Germany and Adam Grundhoff from the Heinrich Pette Institute for Experimental Virology, Hamburg, Germany, together with a group of further researchers conducted a multifactorial investigation at Germany's largest meat processing plant in the state of North Rhine Westphalia, where the outbreak occurred. They traced the events starting with an initial outbreak in May, followed by increasing numbers culminating in more than 1,400 positive cases having been identified by health authorities by 23 June.The investigation of timing of infection events, spatial relationship between workers, climate and ventilation conditions, sharing of housing and transport, and full-length SARS-CoV-2 genotypes, demonstrated that a single employee transmitted the virus to more than 60% of co-workers in a distance of eight metres.Viral genome sequencing was conducted and showed that all the cases shared a common set of mutations representing a novel sub-branch in the SARS-CoV-2 C20 clade. Furthermore, the same set of mutations was identified in samples collected in the time period between the initial infection cluster in May and the subsequent large outbreak in June within the same factory, suggesting that the large outbreak was seeded by cases related to the initial infection cluster.The results indicated that climate conditions, fresh air exchange rates, and airflow, were factors that can promote efficient spread of SARS-CoV-2 over long distances, but that shared accommodation and transport played a smaller role, at least during the initial phase of the outbreak. Earlier studies already suggested that tiny droplets called aerosols may be responsible for so-called super spreading events where a single source transmits the virus to a large number of individuals. Whereas larger droplets typically travel no farther than two metres, aerosols can stay in the air for prolonged periods of time and may deliver infectious viral particles over substantially greater distances, especially in indoor settings.The recurrent emergence of such outbreaks suggests that employees in meat or fish processing facilities should be frequently and systematically screened to prevent future SARS-CoV-2 outbreaks. Furthermore, immediate action needs to be taken to quarantine all workers in a radius around an infected individual that may significantly exceed two metres.Additional studies are required to determine the most important workplace parameters that may be altered to lower infection risk, but optimization of airflow and ventilation conditions are clearly indicated.

Pollution

October 27, 2020

https://www.sciencedaily.com/releases/2020/10/201026220603.htm

Exposure to air pollution increases COVID-19 deaths by 15 percent worldwide, study estimates

Long-term exposure to air pollution has been linked to an increased risk of dying from COVID-19 and, for the first time, a study has estimated the proportion of deaths from the coronavirus that could be attributed to the exacerbating effects of air pollution for every country in the world.

The study, published in In their CVR paper, the researchers write that these proportions are an estimate of "the fraction of COVID-19 deaths that could be avoided if the population were exposed to lower counterfactual air pollution levels without fossil fuel-related and other anthropogenic [caused by humans] emissions."They add that this "attributable fraction does not imply a direct cause-effect relationship between air pollution and COVID-19 mortality (although it is possible). Instead it refers to relationships between two, direct and indirect, i.e. by aggravating co-morbidities [other health conditions] that could lead to fatal health outcomes of the virus infection."The research team includes Professor Jos Lelieveld, of the Max Planck Institute for Chemistry, Mainz, Germany, and the Cyprus Institute Nicosia, Cyprus, Professor Thomas Münzel, from the University Medical Center of the Johannes Gutenberg University, Mainz, and the German Center for Cardiovascular Research, Mainz, and Dr. Andrea Pozzer, from the Max Planck Institute for Chemistry.The researchers used epidemiological data from previous US and Chinese studies of air pollution and COVID-19 and the SARS outbreak in 2003, supported by additional data from Italy. They combined this with satellite data showing global exposure to polluting fine particles known as 'particulate matter' that are less than or equal to 2.5 microns in diameter (known as PM2.5), information on atmospheric conditions and ground-based pollution monitoring networks, to create a model to calculate the fraction of coronavirus deaths that could be attributable to long-term exposure to PM2.5. The results are based on epidemiological data collected up the third week in June 2020 and the researchers say a comprehensive evaluation will need to follow after the pandemic has subsided.Estimates for individual countries show, for example, that air pollution contributed to 29% of coronavirus deaths in the Czech Republic, 27% in China, 26% in Germany, 22% in Switzerland, 21% in Belgium, 19% in The Netherlands, 18% in France, 16% in Sweden, 15% in Italy, 14% in the UK, 12% in Brazil, 11% in Portugal, 8% in the Republic of Ireland, 6% in Israel, 3% in Australia and just 1% in New Zealand.Prof. Jos Lelieveld said: "Since the numbers of deaths from COVID-19 are increasing all the time, it's not possible to give exact or final numbers of COVID-19 deaths per country that can be attributed to air pollution. However, as an example, in the UK there have been over 44,000 coronavirus deaths and we estimate that the fraction attributable to air pollution is 14%, meaning that more than 6,100 deaths could be attributed to air pollution. In the USA, more than 220,000 COVID deaths with a fraction of 18% yields about 40,000 deaths attributable to air pollution."Prof. Münzel said: "When people inhale polluted air, the very small polluting particles, the PM2.5, migrate from the lungs to the blood and blood vessels, causing inflammation and severe oxidative stress, which is an imbalance between free radicals and oxidants in the body that normally repair damage to cells. This causes damage to the inner lining of arteries, the endothelium, and leads to the narrowing and stiffening of the arteries. The COVID-19 virus also enters the body via the lungs, causing similar damage to blood vessels, and it is now considered to be an endothelial disease."If both long-term exposure to air pollution and infection with the COVID-19 virus come together then we have an additive adverse effect on health, particularly with respect to the heart and blood vessels, which leads to greater vulnerability and less resilience to COVID-19. If you already have heart disease, then air pollution and coronavirus infection will cause trouble that can lead to heart attacks, heart failure and stroke."Referring to previous work that suggests that the fine particulates in air pollution may prolong the atmospheric lifetime of infectious viruses and help them to infect more people, Prof. Lelieveld said: "It's likely that particulate matter plays a role in 'super-spreading events' by favouring transmission."Prof. Münzel added: "Particulate matter seems to increase the activity of a receptor on cell surfaces, called ACE-2, that is known to be involved in the way COVID-19 infects cells. So we have a 'double hit': air pollution damages the lungs and increases the activity of ACE-2, which in turn leads to enhanced uptake of the virus by the lungs and probably by the blood vessels and the heart."In their paper, the authors conclude: "Our results suggest the potential for substantial benefits from reducing air pollution exposure, even at relatively low PM2.5 levels. . . . A lesson from our environmental perspective of the COVID-19 pandemic is that the quest for effective policies to reduce anthropogenic emissions, which cause both air pollution and climate change, needs to be accelerated. The pandemic ends with the vaccination of the population or with herd immunity through extensive infection of the population. However, there are no vaccines against poor air quality and climate change. The remedy is to mitigate emissions. The transition to a green economy with clean, renewable energy sources will further both environmental and public health locally through improved air quality and globally by limiting climate change."The study is also the first of its kind to distinguish between fossil fuel-related and other human-made sources of air pollution.One limitation of the research is that epidemiological data from the US were collected at the level of counties rather than from individuals, which means that it is more difficult to exclude confounding factors. Even though 20 factors that could affect the results were accounted for, additional factors cannot be excluded. A second limitation is that data have been collected in middle- to high-income countries (China, US, and corroborated by data from Europe); the calculations were carried out for the whole world, meaning that the results for low-income countries may be less robust.

Pollution

October 23, 2020

https://www.sciencedaily.com/releases/2020/10/201023191033.htm

Metal deposits from Chinese coal plants end up in the Pacific Ocean

Emissions from coal-fired power plants in China are fertilizing the North Pacific Ocean with a metal nutrient important for marine life, according to new findings from a USC-led research team.

The researchers believe these metals could change the ocean ecosystem, though it's unclear whether it would be for better or worse.The study shows that smoke from power plants carries iron and other metals to the surface waters of the North Pacific Ocean as westerly winds blow emissions from Asia to North America. Peak measurements show that up to nearly 60% of the iron in one vast swath of the northern part of the ocean emanates from smokestacks."It has long been understood that burning fossil fuels alters Earth's climate and ocean ecosystems by releasing carbon dioxide into the atmosphere," said Seth John, lead author of the study and an assistant professor of Earth sciences at the USC Dornsife College of Letters, Arts and Sciences. "This work shows fossil fuel burning has a side effect: the release of iron and metals into the atmosphere that carry thousands of miles and deposit in the ocean where they can impact marine ecosystems.""Certain metal deposits could help some marine life thrive while harming other life,'' he added. "There are inevitable tradeoffs when the ocean water's chemistry changes."The study was published on Thursday in the While wind-blown mineral dust from deserts has long been considered an important source of iron to open ocean waters, the new study shows how manmade sources contribute important micronutrients that plankton and algae need. Moreover, the study shows how fossil fuel burning affects not only global warming but marine environments, too.Previous studies have shown widely divergent estimates about how much iron is carried from various land-based sources to the ocean, especially from anthropogenic sources. Iron is a key limiting factor for marine productivity for about one-third of the world's oceans.Instead, the USC-led research team measured metals in surface seawater. They focused on a remote part of the Pacific Ocean, hundreds of miles north of Hawaii and about midway between Japan and California. The region is downwind of industrial emissions in east Asia.In May 2017, they boarded a research vessel and took water samples along a north-south transect at latitudes between 25 degrees and 42 degrees north. They found peak iron concentrations in about the middle, which corresponded with a big wind event over east Asia one month before. The peak iron concentrations are about three times greater than background ocean measurements, the study shows.In addition, the scientists found elevated lead concentrations coincided with the iron hot spots. Other research has shown that most of the lead at the ocean surface comes from manmade sources, including cement plants, coal-fired power plants and metal smelters.Moreover, the metals in the seawater samples bear telltale traces of Chinese industrial sources, the study says."When we collected samples in the ocean, we found that the iron isotope and lead isotope 'fingerprints' from seawater matched those of anthropogenic pollution from Asia," said Paulina Pinedo-Gonzalez, a USC post-doctoral scientist and study author who is now at the Lamont-Doherty Earth Observatory at Columbia University.Finally, the scientists also ruled out upwelling from the deep ocean as a source of the metals by testing water samples at depth.The study has important implications for marine life in the ocean. The North Pacific notably lacks iron, a key micronutrient, so an influx of metals and other substances can help build the foundation for a new ecosystem -- a 'good news, bad news' outcome for Earth."Microscopic iron-containing particles released during coal burning impacts algae growth in the ocean, and therefore the entire ecosystem for which algae form the base of the food chain," John explained. "In the short term, we might think that iron in pollution is beneficial because it stimulates the growth of phytoplankton, which then take carbon dioxide out of the atmosphere as they grow to offset some of the carbon dioxide released during the initial burning process."However, it's totally unsustainable as a long-term geoengineering solution because of the deleterious effects of pollution on human health. Thus, the take-home message is perhaps a better understanding of an unintended side effect of coal burning and the ways in which that can impact ocean ecosystems thousands of miles away."

Pollution

October 23, 2020

https://www.sciencedaily.com/releases/2020/10/201023123135.htm

Marine biology: Sponges as biomonitors of micropollution

Sponges are filter feeders that live on particulate matter -- but they can also ingest microscopic fragments of plastics and other pollutants of anthropogenic origin. They can therefore serve as useful bioindicators of the health of marine ecosystems.

Pollution of the world's oceans owing to anthropogenic input of plastics and other industrial wastes represents an increasing threat to the viability of marine ecosystems. -- And because such pollutants accumulate in fish, crustaceans and mollusks, they enter the food chain and can be ingested by human consumers. Microparticles with dimensions of less than 5 mm present a particularly insidious problem. This class of pollutants includes microplastics and textile fibers, as well as synthetic chemicals found in consumer products such as household cleansers and cosmetics. It is therefore imperative to develop methods for quantifying the magnitude of the threat in order to develop effective measures to mitigate it. In a new publication in the journal Sponges are sometimes referred to as the ocean's vacuum cleaners. They feed on tiny particles suspended in the currents, by filtering them from the seawater that passes through their highly porous tissues -- which are supported by mineralized skeletons in many species. To assess their utility as bioindicators for microparticulate pollutants, Wörheide and colleagues studied 15 samples of a type of mineralized sponges belonging to the class known as 'demosponges' from a coral reef off the coast of the island of Bangka in Northern Sulawesi (Indonesia). "We chose this site because Southeast Asia is a hotspot for plastic pollutants in the oceans," says Elsa B. Girard, lead author of the study. Girard recently graduated from the Master's Program in Geobiology and Paleobiology at LMU, and her contribution to the paper was part of her Master's thesis. "In light of the impact of global warming, and the overexploitation of marine resources, local sponge species could act as useful biomonitors of micropollutants, and help us to develop appropriate measures to reduce the deleterious effects of these substances on reef communities," she explains.In cooperation with specialists from the SNSB- Mineralogical State Collection in Munich and LMU's Department of Chemistry and Center for Nanoscience (CeNS), the biologists used two innovative methods to examine the samples collected from the reef. With the aid of two-photon excitation microscopy (TPE), they confirmed that sponges indeed incorporate microparticles into their tissues. Then they used Raman spectroscopy to characterize the nature of the particles themselves. The data obtained with the second technique revealed the presence of no less than 34 different types of microparticles in sponge tissues. The spectrum ranged from plastics such as polystyrene to cotton and titanium dioxide (TiOThe researchers detected between 90 and 600 particles per gram of dried tissue in their sponge samples. "Since sponges can weigh up to several hundred grams, we estimate on the basis of these results that each can accumulate more than 10,000 particles," says Wörheide. "This makes them promising candidates for the task of monitoring the levels of anthropogenic microparticle pollution in the oceans." With the exception of mollusks, few other species have the properties required of marine bioindicators. According to the authors of the study, sponges have several other "qualifications" for the job. They are abundant and are continuously active as filter-feeders. Moreover, measurements of pollution levels can be carried out on tissue samples (biopsies) without affecting the viability of the organisms.

Pollution

October 23, 2020

https://www.sciencedaily.com/releases/2020/10/201023123128.htm

War on plastic is distracting from more urgent threats to environment, experts warn

A team of leading environmental experts, spearheaded by the University of Nottingham, have warned that the current war on plastic is detracting from the bigger threats to the environment.

In an article published in the peer-reviewed scientific journal, The interdisciplinary team argue that much of the discourse around plastic waste is based on data that is not always representative of the environments that have been sampled. The aversion to plastic associated with this could encourage the use of alternative materials with potentially greater harmful effects.The authors warn that plastic pollution dominates the public's concern for the environment and has been exploited politically, after capturing the attention of the world, for example through emotive imagery of wildlife caught in plastic waste and alarmist headlines. They say small political gestures such as legislation banning cosmetic microplastics, taxing plastic bags, and financial incentives for using reusable containers, as well as the promotion of products as 'green' for containing less plastic than alternatives, risks instilling a complacency in society towards other environmental problems that are not as tangible as plastic pollution.The article's authors call on the media and others to ensure that the realities of plastic pollution are not misrepresented, particularly in the public dissemination of the issue, and urges government to minimise the environmental impact of over-consumption, however inconvenient, through product design, truly circular waste-management, and considered rather than reactionary policy.Dr Tom Stanton, a co-author who led the work while in the University of Nottingham's School of Geography and Food, Water, Waste Research Group, said: "We are seeing unprecedented engagement with environmental issues, particularly plastic pollution, from the public and we believe this presents a once in a generation opportunity to promote other, potentially greater environmental issues."This is a key moment in which to highlight and address areas such as 'throw-away' culture in society and overhaul waste management. However, if there is a continuation in prioritising plastic, this opportunity will be missed -- and at great cost to our environment."The article also highlights that plastics are not the only type of polluting material originating from human activity that contaminates the environment. Other examples include natural textile fibres such as cotton and wool, Spheroidal Carbonaceous Particles (remnants of fossil fuels), and brake-wear particles from vehicles -- all of which are present in different places, where they may have adverse environmental effects. The authors note that these materials are often much more abundant than microplastics and some, such as glass, aluminium, paper, and natural fibres, are associated with 'plastic alternatives' that are marketed as solutions to plastic pollution, but in reality side-step the inconvenience of changing the consumption practices at the root of the problem. The eco-toxicological impacts of some of these materials are less well known than plastic and microplastic pollution, yet they could have significant impacts.The authors conclude that that a behavioural science approach should be taken to assess society's relationship with single-use items and throw-away culture, and to overhaul waste mismanagement.They say there is an understandable desire to minimise the global plastic debris in the environment which should not be discouraged, but positive action to minimise plastic pollution needs to be well informed and should not exacerbate or overshadow other forms of environmental degradation associated with alternative materials.The article states that solutions are likely to come from a greater focus on designing materials and products that can be recycled, that have their end-of-life built in, and that markets and facilities exist to recycle all plastic waste.

Pollution

October 22, 2020

https://www.sciencedaily.com/releases/2020/10/201022123123.htm

Turning streetwear into solar power plants

Our hunger for energy is insatiable, it even continues to rise with the increasing supply of new electronic gadgets. What's more, we are almost always on the move and thus permanently dependent on a power supply to recharge our smartphones, tablets and laptops. In the future, power sockets (at least for this purpose) could possibly become obsolete. The electricity would then come from our own clothes. By means of a new polymer that is applied on textile fibers, jackets, T-shirts and the like could soon function as solar collectors and thus as a mobile energy supply.

Materials capable of using indirect or ambient light for energy generation are already being used in the solar industry. These materials contain special luminescent materials and are called "Luminescent Solar Concentrators," or LSC for short. The luminescent materials in the LSC capture diffuse ambient light and transmit its energy to the actual solar cell, which then converts light into electrical energy. However, LSCs are currently only available as rigid components and are unsuitable for use in textiles because they are neither flexible nor permeable to air and water vapor. An interdisciplinary research team led by Luciano Boesel from the Laboratory for Biomimetic Membranes and Textiles has now succeeded in incorporating several of these luminescent materials into a polymer that provides precisely this flexibility and air permeability.This new material is based on Amphiphilic Polymer Co-Networks, or APCN for short, a polymer that has long been known in research and is already available on the market in the form of silicone-hydrogel contact lenses. The special properties of the polymer -- permeability to air and water vapor as well as flexibility and stability -- are also beneficial to the human eye and are based on special chemical properties. "The reason we chose exactly this polymer is the fact that we are capable of incorporating two immiscible luminescent materials at the nano scale and let them interact with each other. There are, of course, other polymers, in which these materials could be integrated; but this would lead to aggregation, and the production of energy would thus not be possible," explains Boesel.In collaboration with colleagues from two other Empa labs, Thin Films and Photovoltaics and Advanced Fibers, Boesel's team added two different luminescent materials to the gel tissue, turning it into a flexible solar concentrator. Just as on large-scale (rigid) collectors, the luminescent materials capture a much wider spectrum of light than is possible with conventional photovoltaics. The novel solar concentrators can be applied to textile fibers without the textile becoming brittle and susceptible to cracking or accumulating water vapor in the form of sweat. Solar concentrators worn on the body offer an immense benefit for the ever-increasing demand for energy, especially for portable devices.

Pollution

October 21, 2020

https://www.sciencedaily.com/releases/2020/10/201021111555.htm

Legacy pollutants found in migratory terns in Great Lakes region

Chemicals that haven't been manufactured in the U.S. for years or even decades are still turning up in the bodies of migratory terns in the Great Lakes region, a new study finds.

The research focused on three types of compounds: polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and the breakdown products, called metabolites, of dichlorodiphenyltrichloroethane (DDT).Scientists discovered all three kinds of chemicals in the organs of over two dozen common terns in breeding grounds along the Niagara River and the shore of Lake Erie. The pollutants were found at various life stages, in chicks, in juveniles and in adults.Researchers also detected the compounds in emerald shiners, a small fish that is the terns' primary food source in the area.The research was published online on Sept. 3 in Sales of PBDEs, a class of flame retardants used in car seats, carpet padding, mattresses and many other household products, were phased out in the U.S. in 2013. Production of PCBs, once widely used as a coolant or insulating fluid in electrical transformers and capacitators, ended in the country in 1979. And use of DDT, an insecticide, has been prohibited in the U.S. for almost half a century, since 1972. The metabolite of DDT that the team found in the birds and fish is called dichlorodiphenyldichloroethylene (DDE)."These chemicals are still there. They don't just go away. With PCBs, for example, they haven't been produced in the U.S. for a long time now, but you can still find them in the environment, in sediments and in water. They don't degrade for many years. The fish eat organisms that accumulate them, and then the birds eat the fish," says Aga, PhD, Henry M. Woodburn Professor of Chemistry in the University at Buffalo College of Arts and Sciences."The common tern is a threatened species in New York State, and their numbers have not increased much despite state efforts to provide nesting sites and surveillance. This study shows how wildlife is affected by human pollution of aquatic systems and how the chemicals we produce can have a multigenerational effect, being passed from mothers to chicks," says Pérez-Fuentetaja, PhD, Professor of Biology at SUNY Buffalo State and Research Scientist at the Great Lakes Center at SUNY Buffalo State.The levels of PCBs and PBDEs in the birds were high enough to potentially harm the birds' health and affect population recovery, the authors write in their paper.The findings illustrate how household and industrial chemicals have become ubiquitous in the environment, where they can endure for many years, posing risks to wildlife.In the case of terns, the threat begins from the earliest moments of their lives, even before they hatch, says Travis, the paper's first author, who successfully defended his PhD thesis at UB this fall.He notes that the smallest chicks the team studied harbored higher concentrations of the chemicals than older birds and adults, indicating that the compounds are being passed from parent to progeny. To test this hypothesis, Travis has begun work on a study examining the levels of pollutants in the eggs of common terns and other wild aquatic birds."We see these really high concentrations in the smaller chicks, which indicates that there is maternal transfer of contaminants into the eggs," he says."These substances interfere with the reproductive system and are endocrine disruptors," Pérez-Fuentetaja says. "They tax the terns' livers as they have to try and get rid of these pollutants, but the bioaccumulative nature of PCBs, PBDEs and DDEs means that the birds will not be able to fully detoxify themselves, and that they will pass part of their body-load to the next generation. These substances can alter development and neurological processes and could cause deformities, cancers and impaired behavior."The research highlights the risks associated with legacy contaminants, as well as the urgency of protecting the environment as new issues surrounding other classes of persistent chemicals, such as per- and polyfluoroalkyl substances (PFAS), emerge. Aga says that once persistent pollutants become pervasive in water and soil, it's very difficult to get rid of them.The new study shows how long-banned chemicals continue to jeopardize the health of Great Lakes ecosystems."We can't say that all the chemicals we're seeing in the birds are coming from the Great Lakes, as the birds migrate and could be accumulating these compounds in other places along their migration route, too," Travis says. "But the specific types of PCBs and PBDEs we're seeing in the emerald shiners is similar to what we're seeing in the birds. This pattern of chemical concentrations suggests that pollution in the Great Lakes region is the source of at least some of this contamination."He adds, however, that, "One positive outcome of the study is that we only see the metabolite of DDT, called 'DDE,' in the fish. This likely indicates that there aren't new sources of DDT being introduced to Lake Erie and the Niagara River, and that the DDT that was there is breaking down."

Pollution

October 19, 2020

https://www.sciencedaily.com/releases/2020/10/201019133646.htm

Severe air pollution drives food delivery consumption and plastic waste

When the air outside is bad, office workers are more likely to order food delivery than go out for lunch, which in turn increases plastic waste from food packaging, according to a study by researchers from the National University of Singapore (NUS).

Associate Professor Alberto Salvo from the Department of Economics at the NUS Faculty of Arts and Social Sciences and an author of the study, said, "Plastic waste is a growing global environmental concern. While we see more research on the impact plastic pollution is having on the natural environment, there has been less work trying to understand the human behaviour that drives plastic pollution. This is where our study seeks to contribute -- finding a strong causal link between air pollution and plastic waste through the demand for food delivery. Air quality in the urban developing world is routinely poor and in the past decade, the food delivery industry has been growing sharply. The evidence we collected shows a lot of single-use plastic in delivered meals, from containers to carrier bags."The results of the study were published in the journal The NUS team, including Assoc Prof Liu Haoming and Assoc Prof Chu Junhong, focused their study on China, which is among the world's largest users of online food delivery platforms, with 350 million registered users. An estimated 65 million meal containers are discarded each day across China, with office workers contributing over one-half of demand.The study surveyed the lunch choices of 251 office workers repeatedly over time (each worker for 11 workdays) in three often smog-filled Chinese cities -- Beijing, Shenyang and Shijiazhuang -- between January and June 2018. To complement the office-worker survey, the researchers also accessed the 2016 Beijing order book of an online food delivery platform, which broadly represented all market segments served by the food delivery industry -- collecting observational data on 3.5 million food delivery orders from about 350,000 users.Data from the survey and order book were then compared with PM2.5 measurements (fine particles less than 2.5 micrometres in diameter) during lunchtime periods from the air-monitoring network in all three cities. It was observed that PM2.5 levels during these periods were often well above the 24-hour US National Ambient Air Quality Standard of 35 ?g/m³, making pollution highly visible. The researchers were careful to control for confounding factors such as economic activity.Both data sources indicated a strong link between PM2.5 (haze) pollution and food delivery consumption. Correcting for weather and seasonal influences, the firm's order book revealed that a 100 ?g/m³ increase in PM2.5 raised food delivery consumption by 7.2 per cent. The impact of a 100 ?g/m³ PM2.5 shift on office workers' propensity to order delivery was six times larger, at 43 per cent.Assoc Prof Chu from the Department of Marketing at NUS Business School elaborated, "Faced with smog or haze outside, a typical office worker at lunchtime can avoid exposure only by ordering food to be delivered to his or her doorstep. A broader base of consumers has more alternatives to avoiding the outdoor environment on a polluted day, for example, by using a home kitchen when at home. This explains why the impact of air pollution on food delivery is smaller in the firm's order book study than what we observed among workers, particularly those without access to a canteen in their office building. Nevertheless, we find the impact to be economically large also among the broader population served by the food delivery platform that we examined."Over 3,000 photos of meals were submitted by office workers, enabling the NUS team to quantify how much disposable plastic varies across different lunch choices, in particular, meals eaten at the restaurant versus those delivered to the office. The researchers estimated that a 100 ?g/m³ PM2.5 increase raised a meal's disposable plastic use by 10 grams on average -- equivalent to about one-third the mass of a plastic container. Photographs that were published as part of the study indicated that the average delivered meal used 2.8 single-use plastic items and an estimated 54 grams of plastic. The average dine-in meal used an estimated 6.6 grams of plastic, such as in chopstick sleeves or bottles.Based on the order book, the researchers also estimated that on a given day, if all of China were exposed to a 100 ?g/m³ PM2.5 increase in dose as is routinely observed in Beijing, 2.5 million more meals would be delivered, requiring an additional 2.5 million plastic bags and 2.5 million plastic containers.Assoc Prof Liu from the Department of Economics said, "Our findings probably apply to other typically polluted developing-nation cities, such as in Bangladesh, India, Indonesia and Vietnam. Waste management practices vary widely, with wind blowing plastic debris away from uncovered landfills or plastic being discarded into rivers and from there into the ocean. So, with eight million tonnes of plastic estimated to enter the seas each year, our study speaks to a wider issue. Individuals protect themselves from -- and show their distaste for -- air pollution by ordering food delivery which often comes in plastic packaging. It is evident from our study that air pollution control can reduce plastic waste."Moving forward, the researchers will continue working on behavioural feedback by which pollution begets pollution: in particular, to defend themselves from environmental pollution, humans use more natural resources and pollute more. As a recent example, the researchers note how concern over exposure to COVID-19 has led to booming demand for home-delivered meals which are predominantly packaged in plastic. They hope that their work will add to the voices calling for more environmentally friendly packaging and improved waste management.

Pollution

October 19, 2020

https://www.sciencedaily.com/releases/2020/10/201019112158.htm

Light pollution alters predator-prey interactions between cougars and mule deer in western US

A new study provides strong evidence that exposure to light pollution alters predator-prey dynamics between mule deer and cougars across the intermountain West, a rapidly growing region where nighttime skyglow is an increasing environmental disturbance.

The University of Michigan-led study, published online Oct. 18 in the journal The study found that:The animal data used in the study were collected by state and federal wildlife agencies across the region. Collation of those records by the study authors yielded what is believed to be the largest dataset on interactions between cougars and mule deer, two of the most ecologically and economically important large-mammal species in the West."Our findings illuminate some of the ways that changes in land use are creating a brighter world that impacts the biology and ecology of highly mobile mammalian species, including an apex carnivore," said study lead author Mark Ditmer, formerly a postdoctoral researcher at the University of Michigan School for Environment and Sustainability, now at Colorado State University.The intermountain West spans nearly 400,000 square miles and is an ideal place to assess how varying light-pollution exposures influence the behavior of mule deer and cougars and their predator-prey dynamics. Both species are widely distributed throughout the region -- the mule deer is the cougar's primary prey species -- and the region presents a wide range of nighttime lighting conditions.The intermountain West is home to some of the darkest night skies in the continental United States, as well as some of the fastest-growing metropolitan areas, including Las Vegas and Salt Lake City. Between the dark wildlands and the brightly illuminated cities is the wildland-urban interface, the rapidly expanding zone where homes and associated structures are built within forests and other types of undeveloped wildland vegetation.For their study, the researchers obtained detailed estimates of nighttime lighting sources from the NASA-NOAA Suomi polar-orbiting satellite. They collected GPS location data for 117 cougars and 486 mule deer from four states: Utah, Arizona, Nevada and California. In addition, wildlife agencies provided locations of 1,562 sites where cougars successfully killed mule deer."This paper represents a massive undertaking, and to our knowledge this dataset is the largest ever compiled for these two species," said study senior author Neil Carter, a conservation ecologist at the U-M School for Environment and Sustainability.Deer in the arid West are attracted to the greenery in the backyards and parks of the wildland-urban interface. Predators follow them there, despite increased nighttime light levels that they would normally shun. Going into the study, the researchers suspected that light pollution within the wildland-urban interface could alter cougar-mule deer interactions in one of two ways.Perhaps artificial nighttime light would create a shield that protects deer from predators and allows them to forage freely. Alternatively, cougars might exploit elevated deer densities within the wildland-urban interface, feasting on easy prey inside what scientists call an ecological trap.Data from the study provides support for both the predator shield and ecological trap hypotheses, according to the researchers. At certain times and locations within the wildland-urban interface, there is simply too much artificial light and/or human activity for cougars, creating a protective shield for deer.An ecological trap occurs when an animal is misled, or trapped, into settling for apparently attractive but in fact low-quality habitat. In this particular case, mule deer are drawn to the greenery of the wildland-urban interface and may mistakenly perceive that the enhanced nighttime lighting creates a predator-free zone.But the cougars are able to successfully hunt within the wildland-urban interface by carefully selecting the darkest spots on the landscape to make their kill, according to the study. In contrast, cougars living in dark wildland locations hunt in places where nighttime light levels are slightly higher than the surroundings, the researchers found."The intermountain West is the fastest-growing region of the U.S., and we anticipate that night light levels will dramatically increase in magnitude and across space," said U-M's Carter. "These elevated levels of night light are likely to fundamentally alter a predator-prey system of ecological and management significance -- both species are hunted extensively in this region and are economically and culturally important."

Pollution

October 19, 2020

https://www.sciencedaily.com/releases/2020/10/201019103452.htm

A renewable solution to keep cool in a warming world

Month-after-month, year-after-year, the world continues to experience record high temperatures. In response to this and exacerbated by a growing global population, it is expected that air-conditioning demand will continue to rise. A new IIASA-led study explored the pros and cons of seawater air-conditioning as an alternative cooling solution.

Conventional air-conditioning (AC) is the most common technology used for cooling and represents a considerable share of energy demand in warmer regions. An alternative that is not frequently considered, is seawater air-conditioning (SWAC) -- a renewable alternative for cooling that involves pumping seawater from ocean depths of around 700 to 1200 meters and temperatures of 3°C to 5°C to the coast, where it exchanges heat with a district cooling system, and returns the warmer water to the ocean.According to the study published in the journal The results show that whereas conventional air-conditioning systems require a low initial investment cost but the energy costs to operate them are high, for SWAC systems the opposite is true -- while it has a higher initial investment cost, energy costs to operate the system is low.The main potential for SWAC is on small islands in tropical regions, where the distance from the coast to the deep ocean is small, energy costs are high, and warm average temperatures are common throughout the year. For example, in Puerto Plata where the electricity costs are $0.16/KWhe, the cost of conventional AC cooling is around $0.08/KWht. The SWAC solution would cost $ 0.042/KWht, which is 48% less than conventional technologies. In Nauru, assuming the same electricity cost, the SWAC solution would be $0.0185/KWht, which is 77% lower compared with conventional technologies.While district cooling is usually less viable than district heating systems, the low cost of cooling with SWAC processes makes district cooling over short distances a viable alternative. Possible customers with high cooling demands to connect to SWAC district cooling systems include airports, data centers, hotels and resorts, governmental and military facilities, universities, and commercial buildings.The findings further indicate that excess generation of electricity from variable renewable energy sources such as wind and solar energy can be balanced out with the variations in seawater flow in the pipeline of SWAC plants. This cold water would then be stored in thermal energy storage tanks to meet the cooling demand at any time. During months or seasons where cooling demand is low, the cold seawater can be used to increase the efficiency of a chiller to freeze sea or freshwater in the storage tanks. During the months when cooling demand is high, both the SWAC system and the energy stored as ice in the tanks can supply the cooling demand.In addition to the above, the paper also suggests a modification to the normal design that can increase the efficiency of SWAC projects with long pipelines, while allowing for expansion to meet growing cooling demand. The proposal involves increasing the excavation depth of the seawater pump station, which allows an increase in the velocity and flow rate of the seawater inlet pipeline."We call this approach "High Velocity Seawater Air-conditioning." This design configuration allows such projects to be built with an initial cooling load and expand the cooling load modularly through smaller additional capital costs," explains study lead author Julian Hunt, who did this research during his postdoc at IIASA.Other advantages of SWAC includes its reliability as a non-intermittent renewable source of cooling, reduction of greenhouse gas emissions from cooling processes, and the reduction of water consumption in cooling systems. In addition, it could serve as a cheap alternative for large-scale cooling in tropical countries where it could reduce the costs of food and grain storage, thus helping to lower the vulnerability of developing countries to climate change. Given the recent interest in hydrogen production and hydrogen-based economies, SWAC could even be combined with hydrogen liquefaction plants where it could help to reduce energy consumption in the process to liquefy hydrogen by up to 10%.The researchers however caution that despite its potential and many advantages, this technology also has challenges. The return of the seawater should, for instance, be handled with extreme care to minimize its impact on coastal wildlife; retrofitting district cooling infrastructure and buildings could incur high capital costs; and there is a risk of thermal shock and increased nutrient loading in the deep seawater outlet."While it does have its challenges, seawater air-conditioning is an innovative and sustainable technology that has great potential for expanding into a benchmark system for cooling in tropical locations close to the deep sea and will help fulfill our cooling needs in a warming world," Hunt concludes.

Pollution

October 19, 2020

https://www.sciencedaily.com/releases/2020/10/201019103448.htm

Trees bring benefits to society, regardless of their origin

Trees planted in urban spaces provide a multitude of ecosystem services: they reduce air pollution and noise, provide habitat and shelter for other species, and reduce erosion during heavy rains. They also offer opportunities for relaxation, attenuate urban heat islands and contribute both to landscapes and a sense of place. At the same time, trees can be a source of allergens, generate maintenance costs and cause accidents or threats to native biodiversity if introduced from elsewhere. This last point is the subject of an ongoing debate: do introduced species contribute to biodiversity and ecosystem services? Environmental scientists from the University of Geneva (UNIGE) -- working in collaboration with the Botanical Gardens and Conservatory of the City of Geneva -- have analysed a large data-base of trees found in the Geneva region, and systematically assessed the services and inconveniences they generate. The results of the study, to be published in

Trees contribute to the quality of the environment and the well-being of humans. Evaluating these contributions is referred to as the "ecosystem services approach" by environmental specialists. Trees, it goes without saying, bring their share of disadvantages with them both for nature and human beings, chiefly the threat posed by introduced species to the native biodiversity. Martin Schlaepfer is a researcher in UNIGE's Institute of Environmental Sciences and first author of the study. "There's an ongoing philosophical debate concerning this problem at the moment," begins Dr Schlaepfer. "Should we promote native trees and ban -- or at least put limits on -- introduced species? Of all the species introduced into urban areas, only 5% are potentially problematic, such as the Tree of Heaven (Ailanthus altissima) located in the old town of Geneva. But what should we do with the remaining 95% of non-native tree species, and how should we value them?"In an attempt to answer these questions, the environmental specialists from UNIGE and the City of Geneva analysed the databases of tree species found in the urban and semi-urban region of the entire Canton of Geneva, i.e. all isolated or aligned trees excluding forests. The ecosystem services and drawbacks were analysed for each species, whether of native or non-native origin. Following four years of painstaking study, 911 different species were recorded, the vast majority of which -- 90% -- are non-native. This is an exceptional proportion for a city where the current botanical garden in the Nations district, together with the old gardens in the Parc des Bastions -- with over 700 foreign species -- contribute enormously to the diversity.The analysis of ecosystem services showed that the trees are beneficial regardless of their origins. There are, of course, some exceptions: "Three invasive species were identified, and they are indeed potentially problematic when located in semi-natural sites outside the city. But in urban settings there is a low risk of propagation, and we document how they contribute to our well-being. Some non-native trees have been growing in the parks for several centuries, such as cedars and plane trees imported from North Africa and Asia in the 16th and 17th centuries for their aesthetic value, resistance to disease and perennial foliage. They are now part of our cultural heritage. In addition, they have the ability to survive in an urban environment, meaning they can help attenuate urban heat-islands and reduce air-borne pollution. Caution must be employed when planting such non-native species, but they can have a clear beneficial role in certain contexts," adds the researcher.The Geneva study is the first of its type to include an analysis of a broad array of ecosystem services and to encompass both native and non-native species. "Introduced trees are generally listed in the databases of other countries as potential threats, but when it comes to measuring the state of a nation's biodiversity, they are generally dismissed or omitted." The UNIGE research demonstrates that these species provide enormous value and that, as such, they should be integrated into indicators of biodiversity and ecosystem services. "The climate is undergoing profound change, with predictions for our latitudes indicating that within 50 to 100 years -- i.e., the life-span of a large tree -- the climate in Geneva will be like that in southern Italy. That means we must be open to the idea of introducing species today that are able to persist both now and under future climatic conditions," concludes Dr Schlaepfer.

Pollution

October 19, 2020

https://www.sciencedaily.com/releases/2020/10/201019090111.htm

Odors as navigational cues for pigeons

Odors are known to be essential for navigation during homeward orientation and migration of some bird species. Yet little was known about their chemical composition. An international team has now identified volatile organic compounds that can be used for olfactory navigation by homing pigeons and proved the existence of suitable regional chemical gradients in the air on a landscape-scale in Tuscany.

Many bird species can find their way home even after being brought to remote or unfamiliar locations. Over 40 years of research on homing pigeons have shown that environmental odors play a crucial role in this process. Yet the chemical identity of these odors has remained a mystery. An international team of scientists from the Max Planck Institutes for Chemistry (Mainz) and of Animal Behavior (Radolfzell), and the Universities of Konstanz, Pisa and Mainz has now identified potential chemical navigational cues that could be used by homing pigeons. Based on the collected data, the researchers were also able to create regional olfactory maps for marine emissions, biogenic compounds, and anthropogenic mixed air and to establish the existence of regional navigable chemical gradients in the air.During the scientific mission, which took place in 2017 and 2018 in the Italian region of Tuscany, the researchers measured a suite of airborne volatile organic compounds (VOCs) over a period of months at the pigeon's home aviary. Some of these compounds are emitted by trees, the pine fragrance one smells during a walk in the forest. Other pungent natural emissions come from the sea, while still further VOCs can be emitted from industry. The measurements enabled regional maps to be constructed connecting chemicals with wind direction and speed. Additional measurements were taken in selected regional forest environments and by air using an ultralight plane flying at 180 meters -- the average altitude of flying pigeon. The scientists merged the information they had gathered during the field campaigns with GPS tracks obtained from released birds. Thus, they generated multiple regional, horizontal and vertical spatial chemical gradients that can form the basis of an olfactory map."Ornithologists from Germany and Italy have shown in more than 40 years of experiments, that pigeons use airborne odors to navigate home," explains Nora Zannoni, post-doctoral researcher at Max Planck Institute for Chemistry and the study's first author. Those results have shown that pigeons construct an olfactory map based on the distribution of environmental odors they have perceived over several months at the home aviary. This knowledge is then used as a compass at the point of release to return back home from unfamiliar sites. "By proving the existence of regional chemical gradients in the air around the experimental site we provide support for the olfactory navigation hypothesis and with atmospheric measurements we have found which chemicals can be used for navigation," adds Zannoni. Some compounds come from forested areas (monoterpenes) or the sea (DMS) while others are emitted from cities and industrial complexes (trimethylbenzene), spots that act like chemical lighthouses.One of the biggest challenges during this research campaign was its multidisciplinary character. "We had to combine the different approaches of several scientific disciplines -- atmospheric and analytical chemistry, ornithology and animal behavior, computer science and statistics," says Martin Wikelski, managing director at the Max Planck Institute of Animal Behavior."It's amazing really," adds Jonathan Williams the project leader at the MPIC's Atmospheric Chemistry Department in Mainz. "We uncovered these chemical gradients using several tones of ultrasensitive scientific equipment, but the same complex odor information can be analyzed and converted to a regional map by a 400-gram pigeon."

Pollution

October 15, 2020

https://www.sciencedaily.com/releases/2020/10/201015111740.htm

Understanding how toxic PFAS chemicals spread from release sites

A study led by Brown University researchers sheds new light on how pollutants found in firefighting foams are distributed in water and surface soil at release sites. The findings could help researchers to better predict how pollutants in these foams spread from the spill or release sites -- fire training areas or airplane crash sites, for example -- into drinking water supplies.

Firefighting foams, also known as aqueous film forming foams (AFFF), are often used to combat fires involving highly flammable liquids like jet fuel. The foams contain a wide range of per- and polyfluoroalkyl substances (PFAS) including PFOA, PFOS and FOSA. Many of these compounds have been linked to cancer, developmental problems and other conditions in adults and children. PFAS are sometimes referred to as "forever chemicals" because they are difficult to break down in the environment and can lead to long-term contamination of soil and water supplies."We're interested in what's referred to as the fate and transport of these chemicals," said Kurt Pennell, a professor in Brown's School of Engineering and co-author of the research. "When these foams get into the soil, we want to be able to predict how long it's going to take to reach a water body or a drinking water well, and how long the water will need to be treated to remove the contaminants."It had been shown previously that PFAS compounds tend to accumulate at interfaces between water and other substances. Near the surface, for example, PFAS tend to collect at the air-water interface -- the moist but unsaturated soil at the top of an aquifer. However, prior experiments showing this interface activity were conducted only with individual PFAS compounds, not with complex mixtures of compounds like firefighting foams."You can't assume that PFOS or PFOA alone are going to act the same way as a mixture with other compounds," said Pennell, who is also a fellow at the Institute at Brown for Environment and Society. "So this was an effort to try to tease out the differences between the individual compounds, and to see how they behave in these more complex mixtures like firefighting foams."Using a series of laboratory experiments described in the journal Pennell says that insights like these can help researchers to model how PFAS compounds migrate from contaminated sites."We want to come up with the basic equations that describe the behavior of these compounds in the lab, then incorporate those equations into models that can be applied in field," Pennell said. "This work is the beginning of that process, and we'll scale it up from here."Ultimately, the hope is that a better understanding of the fate and transport of these compounds could help to identify wells and waterways at risk for contamination, and aid in cleaning those sites up.

Pollution

October 14, 2020

https://www.sciencedaily.com/releases/2020/10/201014171326.htm

COVID-19 lockdowns averted tens of thousands of premature deaths related to air pollution, study finds

Lockdowns initiated to curb the spread of the coronavirus in China and Europe at the beginning of the pandemic improved air quality, averting tens of thousands of deaths in regions where air pollution has a significant impact on mortality, a new study shows.

According to research published in "We look on these lockdowns as the first global experiment of forced low-emission scenarios," said Paola Crippa, assistant professor in the Department of Civil and Environmental Engineering and Earth Sciences at Notre Dame and corresponding author of the study. "This unique, real-world experiment shows us that strong improvements in severely polluted areas are achievable even in the short term, if strong measures are implemented."Air pollution is considered the leading environmental cause of death. In 2016, the World Health Organization attributed air pollution to 4.2 million premature deaths worldwide, with Western Pacific and Southeast Asian regions being the most affected. Long-term exposure can be hazardous to human health, with premature death associated to lung cancer, ischemic heart disease, stroke and chronic obstructive pulmonary diseases.Crippa and her team integrated advanced computer simulations with measured particulate matter concentrations from more than 2,500 sites in Europe and China in total between Jan. 1, 2016, and June 30, 2020 -- during which both regions initiated lockdowns as COVID-19 began spreading rapidly.The team estimated rates of premature death against four different economic recovery scenarios: an immediate resumption to normal activity and subsequent emissions, a gradual resumption with a three-month proportional increase of emissions, the potential of a second outbreak of COVID-19 between October and December in each region, and a permanent lockdown for the remainder of 2020 in the case of ineffective control strategies."The most surprising part of this work is related to the impact on human health of the air quality improvements," Crippa said. "It was somewhat unexpected to see that the number of averted fatalities in the long term due to air quality improvements is similar to the COVID-19 related fatalities, at least in China where a small number of COVID-19 casualties were reported. These results underline the severity of air quality issues in some areas of the world and the need for immediate action."From February to March, the study found an estimated 24,200 premature deaths associated with particulate matter were averted throughout China compared to 3,309 reported COVID-19 fatalities, and "improvements in air quality were widespread across China because of extended lockdown measures." The study found the situation in Europe to be quite different. While COVID-19 related deaths were far higher in Europe compared to what was reported in China, an estimated 2,190 deaths were still avoided during the lockdown period when compared to averages between 2016 and 2019. The averted fatalities figures become much larger (up to 287,000 in China and 29,500 in Europe) when considering long-term effects, which will depend on the future pathway of economic recovery.The study serves as an example of the need for ad hoc control policies to be developed to achieve effective air quality improvements, said Crippa, and highlights the issue of risk perception between the current immediate crisis of the coronavirus pandemic versus the ongoing crisis of hazardous pollutants in the atmosphere."In China, we saw that lockdowns implied very significant reductions in PM2.5 concentrations, which means that policies targeting industrial and traffic emissions might be very effective in the future," Crippa said. "In Europe those reductions were somewhat smaller but there was still a significant effect, suggesting that other factors might be considered to shape an effective mitigation strategy."Those strategies could include subsidies to electric vehicles, prioritizing public transport in heavily trafficked cities and adoption of more stringent emission limitations for industries. Heating emissions and agriculture are also contributors to total particulate matter concentrations. In the study, researchers stressed that aggressive mitigation strategies to reduce air pollution could achieve significant improvements to health, stating, "If interventions of a similar scale to those adopted to address the COVID-19 pandemic were widely and systematically adopted, substantial progress towards solving the most pressing environmental and health crisis of our time could be achieved."Co-authors of the study include Paolo Giani, Stefano Castruccio, Wenjing Hu and Don Howard, all at Notre Dame, and Alessandro Anav with the Italian National Agency for New Technologies, Energy and Sustainable Economic Development. Crippa is an affiliate member of Notre Dame's Environmental Change Initiative.The study combined aspects of epidemiology, environmental engineering, statistics and philosophy for a comprehensive analysis and interpretation of results through collaboration with Notre Dame's Department of Applied and Computational Mathematics and Statistics and the Department of Philosophy.

Pollution

October 14, 2020

https://www.sciencedaily.com/releases/2020/10/201014141028.htm

Thawing permafrost releases organic compounds into the air

When permafrost thaws due to global warming, not only the greenhouse gases known to all, but also organic compounds are released from the soil. They may have a significant impact on climate change.

Arctic peatlands are very rich in carbon. The effects of the Arctic permafrost thawing on carbon dioxide and methane emissions have been investigated and assessed extensively globally. It is known that when the permafrost thaws, carbon dioxide and methane, which accelerate climate change, are released from the soil. Less attention has been paid to the fact that thawing permafrost may also release volatile organic compounds into the air.Researchers at the University of Helsinki observed in a study for the first time that large quantities of volatile organic compounds, including monoterpenes, sesquiterpenes and diterpenes, are released from permafrost peatland soil thawed in laboratory incubations. The peatland soil samples were collected from Finnish Lapland. The study demonstrated that global warming accelerates the release of these compounds, particularly those with lower volatility, from the Arctic permafrost.In the Arctic region, the anthropogenic influences are weak and aboveground vegetation is scarce. The released organic compounds from thawing permafrost can be highly reactive and contribute to the formation of small particles that suspend in the air. These processes can significantly impact the complex causalities associated with climate change and, consequently, the Arctic climate as well as global warming as a whole.Compounds released from the soil and formed in the air can, for example, increase cloud formation, making increased cloudiness reflect solar radiation away from the Earth, which curbs global warming."For now, it's impossible to say with certainty whether the release of organic compounds accelerates or decelerates climate change. They introduce in any case additional uncertainties to climate change modelling." says Associate Professor Federico Bianchi from the University of Helsinki's Institute for Atmospheric and Earth System Research (INAR).According to Bianchi, much more research is needed to determine the significance of the findings now made. One of the biggest uncertainties in modelling climate change is precisely the effect aerosols have on global warming. Finnish researchers are at the global top in aerosol research.

Pollution

October 14, 2020

https://www.sciencedaily.com/releases/2020/10/201014095135.htm

Plastics threat to South Pacific seabirds confirmed

Plastic gathered from remote corners of the South Pacific Ocean, including nesting areas of New Zealand albatrosses, has confirmed the global threat of plastic pollution to seabirds.

Published on 12 October in the journal It uses data gathered by Canterbury Museum Senior Curator Natural History Dr Paul Scofield and Wellington ornithologist Christopher Robertson in the late 1990s and 2000s."Plastic pollution is a major threat to seabird species, not just here in New Zealand but around the world," says Dr Scofield. "Knowing more about how seabirds interact with plastic might help us solve this problem in the future. At the moment, it's only getting worse."Christopher Robertson, co-author of the study says, "One of the interesting takeaways from this study is that it shows you just how far plastic can travel in the ocean. Some of the areas where we collected the plastic are very remote. To me, that shows that this is a global issue; it's not something a single country can solve on its own.""The samples provided by our colleagues from New Zealand allowed us to assess the patterns of seabird-plastic interactions on a larger scale, across the entire South Pacific Ocean," says the study's lead author, Valeria Hidalgo-Ruz from the Chilean Millenium Nucleus Centre of Ecology and Sustainable Management of Oceanic Islands."The results confirm that even seabirds in one of the most remote areas of the world, the Rapa Nui (Easter Island) ecoregion, are strongly affected by this global problem, highlighting the need for urgent solutions."In the late 1990s and 2000s, fieldworkers gathered thousands of pieces of plastic from albatross nesting sites on the Chatham Islands, Campbell Island and Taiaroa Head in Otago. The birds swallowed most of the plastic while foraging at sea and then regurgitated it at the nesting sites as they tried to feed their chicks.Between 2003 and 2004, the team also examined plastic from the stomachs of Sooty Shearwaters killed by fishing operations around the Chatham Rise and the southeast coast of the South Island.The study compared these plastics with similar samples from other locations around the Pacific including coastal Chile and Rapa Nui. The researchers examined the types of plastic found along with their shape, colour and density.Albatrosses are more likely to eat brightly-coloured plastic, in particular red, green and blue. The birds probably mistake these objects for prey. The study suggests the brightly-coloured fishing gear of commercial fishing operations around the Chatham Islands and in Chile could be the source of some of the plastic found at those nesting sites.Plastics found in the stomachs of diving seabirds like the Sooty Shearwater were dominated by hard, white/grey and round plastic items. The researchers believe most of these objects are ingested accidentally when the birds eat fish or other prey that have consumed plastic.The ingestion of marine plastics is a major issue for seabird conservation and will affect most seabird species by 2050, according to estimates.This work was partially funded by the Department of Conservation's Conservation Science Levy and New Zealand Ministry of Primary Industries.

Pollution

October 13, 2020

https://www.sciencedaily.com/releases/2020/10/201013175028.htm

Trees and lawns beat the heat

In cities, humans replace the natural ground cover with roofs, pavement and other artificial materials that are impervious to water. These surfaces significantly change how the land absorbs and releases energy and cause the urban heat island effect, a phenomenon where developed areas get hotter than nearby rural areas. As climate change pushes many cities towards dangerous temperatures, planners are scrambling to mitigate excessive heat.

One strategy is to replace artificial surfaces with vegetation cover. In water-limited regions such as Utah, a state with one of the lowest annual rainfall rates in the United States, municipalities have to balance the benefit of cooler temperatures with using precious water for irrigation.A new University of Utah study will make those decisions easier for the semi-arid Salt Lake Valley, the largest metropolitan area in Utah located in the northern part of the state. The researchers used 60 sensors to analyze the microclimate in five locations throughout the valley. They found that neighborhoods dominated by impervious surfaces were warmer and drier than the urban parks -- up to 2 degrees warmer in both the daytime and nighttime."It's intuitive -- we've all stood in a parking lot on a hot summer day, and you feel the heat from the ground. And when you're standing on a lawn, it's cooler," said lead author Carolina Gomez-Navarro, postdoctoral researcher at the U. "But we need to back up intuition with data to determine the best strategy for our semi-arid cities."Gomez-Navarro and the team measured the temperature and humidity inside five parks and in their adjacent residential areas from June through August in 2016. They also analyzed how the surrounding landscape impacted air temperature. Surprisingly, they found that lawns reduced daytime and nighttime temperatures even more than trees did. While trees provide shade, lawns and turfgrass act like a swamp cooler -- water moves through the plant, evaporating from tiny holes in the leaves and cooling the air.Much of the heat that builds up during the day dissipates at night. The more open the land, the better heat can escape into the atmosphere. An area with many trees acts like a greenhouse, trapping heat close to the ground. The study concluded that a mixture of dispersed trees and grass is the most effective way to cool temperatures in the Salt Lake Valley."Understanding how ground cover impacts temperature is crucial for city planners to weigh the benefits and costs of its landscape design," said Gomez-Navarro. "This land used to be a valley of bushes and bare soil. Any vegetation we add is going to need lots of irrigation and modify the landscape in many ways."The paper was published on October 13, 2020 in the journal Gomez-Navarro focused on five parks and the adjacent neighborhoods throughout the Salt Lake Valley: Hunter (northwest), Lone Peak (southeast), Midvale City (south central), Southridge (northwest) and Sugar House (northeast). Each location had 12 sensors that measured temperature and humidity: six within the park and six in the residential areas. Gomez-Navarro analyzed ground cover in a 10-meter diameter around each sensor using satellite images to estimate the percentage of the roofs, pavement, trees or turfgrass. She found that the more turfgrass in a given area, the lower the temperature.She analyzed canopy cover by taking photos of the sky above each sensor with a fish eye lens. She used software that calculated the area that trees obstructed the sky. She found that the more open the landscape, the hotter the daytime temperature. The more canopy cover, the more shade reduced temperature.The authors expected there to be temperature and humidity differences between the parks and neighborhoods. They were surprised, however, that turfgrass had nearly the same impact on air temperature as trees. It seems counterintuitive because of the difference between air temperature and perceived temperature. Perceived temperature is how humans feel the environment. Wind, air temperature, humidity and solar radiation all factor into how comfortable we are."We didn't measure human comfort in this study, but we know that the amount of solar radiation on our skin has a big impact on the perceived temperature," said Gomez-Navarro. "Even if the air temperature is the same, we feel much cooler under the shade of a tree because it blocks some of the radiation."Next, Gomez-Navarro will study how different landscapes directly affect how humans feel comfortable in their environment, and how plant cover type affect soil water loss."It's going to keep getting hotter and parks can be a refuge from the heat. But exactly how many degrees can they cool the air? And what should we plant to maximize this cooling?" said co-author Diane Pataki, professor of biology at the U. "It's getting easier and cheaper to measure temperature all over parks and neighborhoods, and we're going to need this information to make good decisions about future park designs."

Pollution

October 13, 2020

https://www.sciencedaily.com/releases/2020/10/201013124157.htm

People can do more than use less plastic to help save the Great Barrier Reef

Many Australians do not know what they can individually do to make a difference to the health of the World Heritage-listed Great Barrier Reef (GBR), according to a survey led by QUT researchers.

The researchers found most Australians are not making a connection between climate change and reef health and say there is more individuals could do on this front, both in the home and to influence government policies.Senior Research Fellow Dr Angela Dean conducted the online survey of 4,285 Australians with Professor Kerrie Wilson, Director of QUT's Institute for Future Environments, and Dr Robyn Gulliver from the University of Queensland.The resulting paper, "Taking action for the Reef?" -- Australians do not connect Reef conservation with individual climate-related actions, has been published in "While there are many threats to reef health, including poor water quality stemming from land-based runoff, cyclones and crown-of-thorns starfish, climate change represents the greatest threat to our Great Barrier Reef," said Dr Dean."Record-breaking marine heatwaves over the past 10 years have seen an increasing frequency and severity of mass coral bleaching events."Yet while many Australians express appreciation and concern for the GBR, they don't necessarily know how to take the next steps to help the Reef."The research team asked survey participants the question "what types of actions could people like you do that would be helpful for the GBR?""Just 4 per cent mentioned a climate action and 12.3 per cent wanted to help but couldn't think of anything they could do on a personal level," said Professor Wilson"Only one in 25 respondents identified at least one specific action that related to climate change. Almost one third listed donating money and the most common group of responses related to pollution, especially plastics."Professor Wilson said the vast majority of those surveyed referenced reducing their plastic consumption over using less energy in the home."Only a handful of people considered that they could make a difference by doing things like driving less, reducing their use of air-conditioning and sourcing electricity from renewable retailers," she said."As for what we call public-sphere actions, many more respondents suggested policies such as banning sunscreens or stopping commercial fishing, rather than any climate-related civic action such as lobbying governments or donating to charities working on reducing emissions."Dr Dean added because everyone can support action on climate change, everyone in Australia can help the Reef, no matter where they live."Some people might choose to focus on actions at home, reducing electricity use or changing to renewable energy sources," Dr Dean said."But perhaps more important is sharing our support for protecting the Reef and encouraging Governments step up to show leadership and action on climate change."

Pollution

October 12, 2020

https://www.sciencedaily.com/releases/2020/10/201012115944.htm

Australian valley a 'natural laboratory' to test carbon sequestration theory

Geoscientists at the University of Sydney have discovered a natural laboratory to test claims that the carbon captured during the erosion and weathering of common rocks could be a viable mitigation strategy against global warming.

That laboratory is the Tweed River valley in north-eastern New South Wales."When common rocks, known as olivine, chemically break down, they absorb carbon dioxide to form carbonates that can then be washed into the oceans," said lead author of the study, Kyle Manley, a student at the University of Irvine in California, who started the research while studying at Sydney."In that way, river valleys like the Tweed can act as carbon sinks."The carbonates formed in this process later become the shells of marine animals and corals. Over millions of years, these remnants can form huge undersea carbonate structures. Occasionally they are pushed above sea level, such as the White Cliffs of Dover in England.In order to combat global warming, some have proposed olivine weathering and its carbon capture could be harnessed to absorb millions of tonnes of carbon dioxide from the atmosphere."But those ideas haven't really been tested at scale," said Mr Manley, who started the study while on undergraduate exchange at the School of Geosciences at the University of Sydney, completing it at the University of Colorado, Boulder.Research now published in the journal Co-author Dr Tristan Salles from the School of Geosciences at the University of Sydney said: "We ran seven scenarios up to 2100 and 2500 to see how much carbon might be absorbed in different climatic conditions."In all scenarios we estimate millions of tonnes of carbon dioxide could be absorbed -- but this is a drop in the ocean of the billions of tonnes a year of carbon pollution expected to be emitted over the coming decades and centuries."The seven scenarios also describe a complex and interconnected interplay between weathering and sea-level rise that will see oceans encroach along the Tweed coast. However, in some areas, extensive weathering will deposit huge amounts of new sediment onto the coastal plain.Dr Salles said: "Increased global temperatures are likely to see increased rainfall in this part of Australia, which will greatly accelerate the weathering process of olivine rocks."Our modelling shows that in some parts of the Tweed floodplain between 3.8 and 6.5 metres of sediment could be deposited. A counter-process will see coastal erosion from the encroaching ocean."From their initial modelling of the Tweed catchment, the scientists estimate between 57 and 73 million tonnes of carbon dioxide a year could be absorbed in olivine weathering by the end of this century. The United Nations mid-range estimate for carbon emissions at 2100 is about 70 billion tonnes a year, meaning a site like the Tweed catchment would absorb less than 0.1 percent of total carbon emissions.The scientists used modelling data from the Australian government and the UN's International Panel on Climate Change and from extensive data on the Tweed River valley from Geoscience Australia and the Three Dimensional Great Barrier Reef project (3DGBR)."Nobody is suggesting that carbon sequestration via olivine weathering will solve our problems," said co-author Professor Dietmar Müller. "But given that there are proposals to artificially enhance this weathering process to absorb carbon pollution, it is important we understand just how viable this could be."The scientists say that their modelling will assist in the identification of other regions where climate change could create environments in which enhanced natural carbon sequestration might occur."What we did find is that the rate and magnitude of sea-level rise is the dominant control of where, when and how much sediment is deposited in such a region," Mr Manley said."Climate change will throw these river systems out of equilibrium, so there is still much work to do to understand how they will operate as natural carbon sinks."

Pollution

October 9, 2020

https://www.sciencedaily.com/releases/2020/10/201009131424.htm

School absences correlate to impaired air quality

In Salt Lake City schools, absences rise when the air quality worsens, and it's not just in times of high pollution or "red" air quality days -- even days following lower levels of pollutions saw increased absences.

Research is still ongoing, and the evidence isn't yet conclusive enough to draw a cause-and-effect relationship between air quality and children's absences from school but the correlation, according to Daniel Mendoza, a research assistant professor in the Department of Atmospheric Sciences and visiting assistant professor in the Department of City & Metropolitan Planning, merits further exploration. Mendoza and his colleagues published their results in Air pollution is harmful for not only the health, but also the education and well-being of children in our community," says study co-author Cheryl Pirozzi, assistant professor in the Division of Respiratory, Critical Care, and Occupational Pulmonary Medicine. "Even at relatively low levels that many people would not think to be harmful air pollution is associated with increased school absences.""Any pollution is bad," Mendoza says. "And these lower levels of pollution, which are still harmful to our health, have been understudied."Mendoza, who also holds appointments as adjunct assistant professor in the Pulmonary Division at the School of Medicine and as senior scientist at the NEXUS Institute, and his interdisciplinary colleagues looked at absence data from 36 schools in the Salt Lake City School District and compared them with ozone and air particulate matter levels in those neighborhoods from 2015 to 2018.This kind of neighborhood-level air quality modeling requires a network of research-quality air sensors, and such a network has been building in the Salt Lake Valley over the last several years, operated by the U and by the state Division of Air Quality. That network includes mobile sensors on light rail trains as well as stationary research and regulatory grade sensors."These are critical because now we can see small nuances, small differences across neighborhoods," Mendoza says. "Now we can see how one school, for example, had slightly higher or slightly lower values of ozone and particulate matter. And now, instead of looking at the difference between green and yellow days, we can actually see small amounts of variability because of the density of our networks."To understand the findings, it's important to first review how air quality conditions are reported. Particulate matter is most often reported as PMAlthough the study looked at elementary, middle and high schools, the authors write that elementary students may be most vulnerable to health effects from air pollution."Children are particularly susceptible to the health effects of air pollution," Pirozzi says, "and it is possible that health effects, such as respiratory tract infections or asthma exacerbations, may lead to them missing more school, which can have long-term consequences for them."Across the school district, they found, school absences increased by 1.04 per ?g/m"So what that really leads us to think is that even low levels of poor air quality can, in a cumulative manner lead to negative health outcomes -- in this case increased school absences. Even on green air quality days, when the pollution was just slightly elevated, if we had several of those days, then kids would still be absent."Additionally, the researchers write that there may be a disparity between eastside and westside schools. Schools on the west side, with a higher proportion of residents from minority groups, already have a higher rate of absences than the comparatively more affluent east side and are slightly more affected by the same level of pollution. The disparity isn't yet statistically significant, and Mendoza hopes that an interdisciplinary team can further study these socioeconomic factors.Mendoza acknowledges that there may be more factors at play that could account for some of the absences. Poor air quality days in the winter tend to be colder days, for example, and some children might stay home to stay out of the cold."So we're not saying that this is all due to poor air quality," he says. "We do know that there are more social and demographic variables at play here, but we already know the best way to estimate the pollution is in your zip code is by quantifying the percent of minority residents."Absences come at a cost to schools, families and the larger economy. As part of the study, the researchers tried to estimate those costs.First, the cost to schools. Using average per-pupil spending, the authors found that the state spends $41.30 per student per day -- funding that doesn't benefit a student who's absent.Next, the cost to families. Often a child staying home from school means a parent staying home from work. At an average hourly wage of $23.74, an absence can cost an hourly worker close to $200 a day. For families who receive free or reduced lunch, the cost of food then reverts to the family on days home.And there are costs to the larger economy as well. Factoring in lost wages, lost taxes and lost productivity due to absences, reducing air pollution by 50 percent could save Utah's economy around $426,000 per year just from reducing absences in the Salt Lake School District. This result, the authors say, shows how reducing school absenteeism can and should be considered a benefit of improving air quality in the Salt Lake Valley."This is definitely not negligible," Mendoza says. "This is a real definite number, very close to half a million dollars in terms of income that does not need to be lost."

Pollution

October 7, 2020

https://www.sciencedaily.com/releases/2020/10/201007182336.htm

Urban air pollution may make COVID-19 more severe for some

As the pandemic persists, COVID-19 has claimed more than 200,000 lives in the United States and damaged the public health system and economy. In a study published on September 21 in the journal

"Both long-term and short-term exposure to air pollution has been associated with direct and indirect systemic impact on the human body by enhancing oxidative stress, acute inflammation, and respiratory infection risk," says Donghai Liang of Emory University, co-first author on the paper along with Liuhua Shi.The researchers analyzed key urban air pollutants, including fine particle matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3), across 3,122 counties in the United States from January to July. To examine the association between ambient air pollutants and the severity of COVID-19 outcomes, they investigated two major death outcomes, the case-fatality rate (i.e., number of deaths among the people who are diagnosed with COVID-19) and the mortality rate (i.e., number of COVID-19 deaths in the population). The two indicators can imply the biological susceptibility to deaths from COVID-19 and offer information of the severity of the COVID-19 deaths in the general population, respectively.Of the pollutants analyzed, NO2 had the strongest independent correlation with raising a person's susceptibility to death from COVID-19. A 4.6 parts per billion (ppb) increase of NO2 in the air was associated with 11.3% and 16.2% increases in COVID-19 case-fatality and mortality rate, respectively. Moreover, Liang and his colleagues discovered that just a 4.6 ppb reduction in long-term exposure to NO2 would have prevented 14,672 deaths among those who tested positive for the virus. The team also observed a margin-ally significant association between PM2.5 exposure and COVID case-fatality rate, whereas no notable associations were found with O3."Long-term exposure to urban air pollution, especially nitrogen dioxide, might enhance populations' susceptibility to severe COVID-19 death outcomes," says Liang. "It's es-sential to deliver this message to public health practitioners and policymakers in order for them to consider protecting vulnerable populations that lived in historically high NO2 pollution including the metropolitan areas in the state of New York, New Jersey, California, and Arizona."Liang also noted that air pollution is a health equity issue: the burden of NO2 pollution is not evenly shared. People with lower income and people of color often face higher exposure to ambient air pollution and may experience a more significant impact from the pollutants. Not having many choices in residency, many live by highways or industrial sites, which makes them especially vulnerable to air pollution."The continuations and expansions of current efforts to lower traffic emissions and ambient air pollution might be an important component of reducing the population-level risk of COVID-19 case-fatality and mortality in the United States," says Liang.This project was supported by the Emory HERCULES Exposome Research Center through the National Institute of Environmental Health Sciences. Further funding was provided by the National Science Foundation.

Pollution

October 6, 2020

https://www.sciencedaily.com/releases/2020/10/201006153526.htm

Evidence of Alzheimer's, Parkinson's and MND in brains of young people exposed to dirty air

Researchers looking at the brainstems of children and young adults exposed lifelong to air pollution in Mexico City have discovered disturbing evidence of harm.

Previous studies have linked fine particulate air pollution exposure with Alzheimer's disease, and researchers have also reported evidence of air pollution-derived nanoparticles in the frontal cortex of the brain.But after examining the brainstems of 186 young Mexico City residents aged between 11 months and 27 years of age, researchers, including Professor Barbara Maher from Lancaster University, found markers not only of Alzheimer's disease, but also of Parkinson's and of motor neurone disease (MND) too. These markers of disease were coupled with the presence of tiny, distinctive nanoparticles within the brainstem -- their appearance and composition indicating they were likely to come from vehicle pollution.This has led researchers to conclude that air pollution of this nature -- whether inhaled or swallowed -- puts people at risk of potential neurological harm. The brainstem is the posterior part of the brain which regulates the central nervous system, controls heart and breathing rates, and how we perceive the position and movement of our body, including, for example, our sense of balance.Professor Maher said: "Not only did the brainstems of the young people in the study show the 'neuropathological hallmarks' of Alzheimer's, Parkinson's and MND, they also had high concentrations of iron-, aluminium- and titanium-rich nanoparticles in the brainstem -- specifically in the substantia nigra, and cerebellum."The iron-and aluminium-rich nanoparticles found in the brainstem are strikingly similar to those which occur as combustion- and friction-derived particles in air pollution (from engines and braking systems)."The titanium-rich particles in the brain were different -- distinctively needle-like in shape; similar particles were observed in the nerve cells of the gut wall, suggesting these particles reach the brain after being swallowed and moving from the gut into the nerve cells which connect the brainstem with the digestive system."The 'neuropathological hallmarks' found even in the youngest infant (11 months old) included nerve cell growths, and plaques and tangles formed by misfolded proteins in the brain. Damage to the substantia nigra is directly linked with the development of Parkinson's disease in later life. Protein misfolding linked previously with MND was also evident, suggesting common causal mechanisms and pathways of formation, aggregation and propagation of these abnormal proteins.The one thing common to all of the young people examined in the study was their exposure to high levels of particulate air pollution. Professor Maher says that the associations between the presence of damage to cells and their individual components -- especially the mitochondria (key for generation of energy, and signalling between cells) -- and these metal-rich nanoparticles are a 'smoking gun'.Such metal-rich particles can cause inflammation and also act as catalysts for excess formation of reactive oxygen species, which are known to cause oxidative stress and eventual death of neurons. Critically, the brainstems of age- and gender- matched controls who lived in lower-pollution areas have not shown the neurodegenerative pathology seen in the young Mexico City residents.These new findings show that pollution-derived, metal-rich nanoparticles can reach the brainstem whether by inhalation or swallowing, and that they are associated with damage to key components of nerve cells in the brainstem, including the substantia nigra.Even in these young Mexico City residents, the type of neurological damage associated with Alzheimer's, Parkinson's and motor neurone diseases is already evident. These data indicate the potential for a pandemic of neurological disease in high-pollution cities around the world as people experience longer lifespans, and full symptoms of earlier, chronic neurological damage develop.Professor Barbara Maher said: "It's critical to understand the links between the nanoparticles you're breathing in or swallowing and the impacts those metal-rich particles are then having on the different areas of your brain."Different people will have different levels of vulnerability to such particulate exposure but our new findings indicate that what air pollutants you are exposed to, what you are inhaling and swallowing, are really significant in development of neurological damage."With this in mind, control of nanoparticulate sources of air pollution becomes critical and urgent."

Pollution

October 6, 2020

https://www.sciencedaily.com/releases/2020/10/201006114223.htm

Climate-friendly cooling to help ease global warming

A new IIASA-led study shows that coordinated international action on energy-efficient, climate-friendly cooling could avoid as much as 600 billion tonnes CO

Hydrofluorocarbons (HFCs) are mainly used for cooling and refrigeration. While they were originally developed to replace ozone-depleting substances that are being phased out under the Montreal Protocol, many HFCs are potent greenhouse gases with a global warming potential up to 12,400 times that of COThe Kigali Amendment to the Montreal Protocol, which entered into force in 2019, aims to phase down the consumption of HFCs by 2050. While previous agreements have resulted in improvements in the design and energy performance of, for instance, cooling equipment, the Kigali Amendment is the first to include maintaining and/or enhancing the energy efficiency of cooling technologies as an explicit goal. According to the authors of the study, which has been published in the journal The researchers developed a range of long-term scenarios for HFC emissions under varying degrees of stringency in climate policy and also assessed co-benefits in the form of electricity savings and associated reductions in emissions. The results indicate that, due to technical opportunities to improve energy efficiency in cooling technologies, there is potential for significant electricity savings under a well-managed phase-down of HFCs."Our results show that the global cumulative HFC emissions from refrigerant use in cooling technologies would have been over 360 billion tonnes CO"We found that if technical energy efficiency improvements are fully implemented, the resulting electricity savings could exceed 20% of future global electricity consumption, while the corresponding figure for economic energy efficiency improvements would be about 15%," adds study coauthor and senior IIASA researcher Lena Höglund-Isaksson.The researchers say that the combined effect of HFC phase-down, improvement of energy efficiency of stationary cooling technologies, and future changes in the electricity generation fuel mix would prevent between 411 and 631 billion tonnes COThe findings further show that reduced electricity consumption could mean lower air pollution emissions in the power sector, estimated at about 5 to 10% for sulfur dioxide, 8 to 16% for nitrogen oxides (NOx), and 4 to 9% for fine particulate matter (PM2.5) emissions compared with a pre-Kigali baseline."To be consistent with 1.5°C scenarios, by 2050 HFCs should be reduced by between 70 and 80% compared to 2010 levels. According to the Kigali Amendment and Maximum Technically Feasible Reduction (MTFR) scenarios we analyzed, we could achieve 92.5% and 99.5% reductions in 2050 compared to 2010 levels, respectively. This means that both scenarios surpass the 1.5 °C threshold. If carefully addressed during the transition to alternatives that have the potential to relieve global warming, improvement potentials for energy efficiency in cooling technologies are extensive and can bring significant electricity savings," Purohit concludes.

Pollution

October 5, 2020

https://www.sciencedaily.com/releases/2020/10/201005112133.htm

Dust dampens albedo effect, spurs snowmelt in the heights of the Himalayas

Dust blowing onto high mountains in the western Himalayas is a bigger factor than previously thought in hastening the melting of snow there, researchers show in a study published Oct. 5 in

That's because dust -- lots of it in the Himalayas -- absorbs sunlight, heating the snow that surrounds it."It turns out that dust blowing hundreds of miles from parts of Africa and Asia and landing at very high elevations has a broad impact on the snow cycle in a region that is home to one of the largest masses of snow and ice on Earth," said Yun Qian, atmospheric scientist at the U.S. Department of Energy's Pacific Northwest National Laboratory.Qian and Chandan Sarangi, formerly a postdoctoral associate at PNNL and now at the Indian Institute of Technology Madras in India, are corresponding authors of the study.More than 700 million people in southeast Asia, as well as parts of China and India, depend on melting snow in the Himalayas for much of their freshwater needs in summer and early fall, driving the urgency of scientists ferreting out the factors that influence earlier snowmelt in the region.In a study funded by NASA, scientists analyzed some of the most detailed satellite images ever taken of the Himalayas to measure aerosols, elevation, and surface characteristics such as the presence of dust or pollution on snow.Dark objects on or in snow absorb sunlight more effectively than pure white snow, whose reflectivity fends off sunlight so forcefully that snow can be blinding on a bright, sunny day. But snow near an object that absorbs sunlight -- like snow on a dark-colored car where some of the roof is exposed -- heats up and melts faster than pristine snow.Scientists use the word "albedo" to discuss how well a surface reflects sunlight. Dirty snow has a low albedo, while pure snow has a high albedo. Dust and soot lower snow's albedo, causing the snow to absorb more light, heating up and melting snow faster.The albedo effect at high elevations is crucial to life for millions of people who rely on snowmelt for their drinking water. Darker, dirtier snow melts faster than pure snow, changing the timing and amount of snowmelt and affecting agriculture and other aspects of life.The team found that dust plays a much larger role melting snow than soot and other forms of pollution, known as black carbon, at elevations above 4,500 meters. Below that, black carbon dominates.It's a surprise for scientists, who note that far more studies have explored the role of black carbon than dust in snowmelt.The dust blows into the western Himalayas from the west -- from the Thar Desert in northwestern India, from Saudi Arabia and even from the Sahara in Africa. The dust comes in winds thousands of feet high, at what scientists call elevated aerosol layers.While desert dust is natural, the scientists say that its prevalence in the Himalayas is not without human influence. Increasing temperatures have changed atmospheric circulation, affecting the winds that can carry dust hundreds or thousands of miles. Changing land-use patterns and increasing development have reduced vegetation, liberating dust that otherwise would have been tied to the land.Qian was one of the first scientists to develop sophisticated modeling tools to analyze how impurities like dust and soot affect the rate at which snow melts. He did that early work more than a decade ago in the mountains of the U.S. West."It's likely that these results translate to other high mountain chains, including the Rockies, Sierras and Cascades in North America and several mountain chains in Asia, such as the Caucuses and Urals," Qian said.Much of the data for the study comes from satellite images obtained by multiple NASA instruments, including NASA's Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), OMI (Ozone Monitoring Instrument), and MODIS (Moderate Resolution Imaging Spectroradiometer). These instruments can detect dust and other aerosols in the atmosphere, and measure snow coverage and albedo, from hundreds of miles above Earth. Equipped with data from these and other sources, the PNNL team did extensive computer modeling of the processes at work.Dust particles usually stay in snow longer than black carbon, the scientists noted. Dust is usually a little bit bigger; it's not as easily blown off the snow and it doesn't fall through snow as easily. There's also a lot more of it."The snow in the western Himalayas is receding rapidly. We need to understand why this is happening, and we need to understand the implications," said Sarangi. "We've shown that dust can be a big contributor to the accelerated snowmelt. Hundreds of millions of people in the region rely on snow for their drinking water -- we need to consider factors like dust seriously to understand what's happening."Qian notes that as the climate warms and snow lines move higher, scientists expect the role of dust to become even more pronounced in the Himalayas -- a region that, aside from the Arctic and Antarctic regions, contains the biggest mass of snow and ice on the planet.

Pollution

October 1, 2020

https://www.sciencedaily.com/releases/2020/10/201001113555.htm

800 million children still exposed to lead

As many as 800 million children have dangerously high lead values in their blood. The neurotoxin can cause permanent brain damage.

The huge international numbers come from a new report from Pure Earth and UNICEF. Pure Earth works to solve pollution problems that can be harmful to humans."A child's earliest years of life are characterized by rapid growth and brain development. This makes children particularly vulnerable to harmful substances in the environment," says Kam Sripada, a postdoc at the Norwegian University of Science and Technology (NTNU) who has contributed to the report.Sripada collaborates with international organizations to research social health inequalities, especially among children."Exposure to lead during pregnancy and early in life can lead to a child never reaching his or her potential," she says.Sripada works at NTNU's Center for Global Health Inequalities Research (CHAIN) in collaboration with the Norwegian Institute of Public Health and UNICEF.Lead is an element, but also a powerful neurotoxin that can cause damage at a level as low as five micrograms of lead per decilitre of blood. Lead poisoning can be acute, and can cause everything from stomach pain to brain damage, coma and death.But lead poisoning can also come on slowly, because it accumulates in the body over a long period of time. The most common symptom is lethargy due to anaemia. High lead levels can attack blood and bone marrow, the nervous system and the kidneys.Lead poisoning can also contribute to a lower IQ and behavioural problems that can last a lifetime."Lead is a health threat to children in every single country in the world. However, children in low- or middle-income countries are the most vulnerable, especially in South Asia and among marginalized groups in general. There are major social differences when it comes to lead exposure and other environmental toxins that we need to address," says Sripada.A lot of the lead comes from lead-acid batteries that are not responsibly recycled. The number of motor vehicles has tripled in low- and middle-income countries in the last 20 years, which in turn has led to a sharp increase in lead-containing batteries. About half of the batteries are not properly recycled or recovered.Water pipes, industry, paint and a number of household products such as canned foods, contaminated spices, make-up and toys also contribute. Lead that was previously used in gasoline is still found in the soil to this day.Indirectly, countries can suffer enormous income losses as the children grow up with these sources of lead exposure. As adults, they often are not able to contribute optimally to the societal economy."This is a report with global significance," says NTNU Professor Terje Andreas Eikemo, who heads CHAIN.Both the World Health Organization (WHO) and the Centers for Disease Control and Prevention in the United States believe that the situation requires international measures, such as more information and strengthening of the health care system in several countries."This report shines the spotlight on lead as an important global environmental and health problem that is especially tied to children's health and development," says Heidi Aase, who heads the NeuroTox study at the Norwegian Institute of Public Health.The NeuroTox study examines relationships between environmental toxins in the mother's womb, including lead, and various measures of brain development. ADHD, autism and cognitive functions are considered in a large sample of Norwegian children. Environmental toxins found in the mother's body during pregnancy can affect the baby's development.CHAIN will use the NeuroTox study to study relationships between socio-economic factors, such as income, education and living conditions, and levels of lead and other environmental toxins in pregnant women and their children."The UNICEF report and other studies show that poverty is associated with higher lead levels and an increased risk of harmful effects on health. We'll investigate whether this picture applies to pregnant women and children in Norway as well," says Aase.The research results from NeuroTox and CHAIN can also be used in different ways internationally, such as to prevent social inequality in health including the harmful effects of environmental toxins.The average blood levels of lead in children from low- and middle-income countries in the UNICEF report are far higher than in Norwegian children. Nevertheless, the report has calculated that many Norwegian children may have lead levels above the limit that we know has harmful effects on brain development."This is concerning," says NeuroTox researcher Gro Dehli Villanger.Studies show that damage to the brain and nervous system can occur at far lower lead levels than the limit used in the report."As of today, no value limit has been established that is considered safe and therefore the number of children affected could be much higher both in Norway and in other countries," says Villanger.

Pollution

September 30, 2020

https://www.sciencedaily.com/releases/2020/09/200930194848.htm

Marine heatwaves can strengthen hurricanes

Oceanographers have found that a hurricane can be considerably strengthened in the Gulf of Mexico through the compounding effects of two extreme weather events. This process could continue in the future as ocean temperatures continue to rise around the world, according to a study co-authored by a Texas A&M University at Galveston professor.

Kyeong Park, professor and head of the Department of Marine and Coastal Environmental Science at Texas A&M-Galveston, and colleagues have had their work published in The team examined Hurricane Michael, the first Category 5 hurricane on record to impact the Florida Panhandle, in October 2018. Prior to Hurricane Michael, Tropical Storm Gordon in early September mixed cold bottom water with warm surface water, lowering the surface water temperature and increasing the capacity of absorbing more heat.During the subsequent atmospheric heatwave, the water column could absorb more heat energy resulting in a marine heatwave, which later was used to strengthen Hurricane Michael to a Category 5 storm. Hurricane Michael became much stronger than was forecasted because it did not take into account this compound effect."During summer in the ocean, solar energy increases air temperature and surface water temperature so much that the entire water column -- from surface to bottom -- cannot absorb heat from the atmosphere," Park said.Water in the Gulf of Mexico in the summer months is especially prone to these conditions, the study concluded. The compound effect of Tropical Storm Gordon followed by an atmospheric heatwave provided an optimal condition for Hurricane Michael to become stronger than expected."It does appear that a storm or hurricane can get stronger if the marine conditions are right," Park said. "Hurricanes Sally and Laura in the past few weeks are good examples of stronger hurricanes because of the compound effect we described in our paper. This pattern could also exacerbate other environmental problems in sensitive ecosystems such as bleaching of coral reefs, hypoxia (low oxygen in the water) and other problem that are predicted as global warming continues."

Pollution

September 30, 2020

https://www.sciencedaily.com/releases/2020/09/200930144428.htm

How urban grime affects chemical reactions in cities

Many city surfaces are coated with a layer of soot, pollutants, metals, organic compounds and other molecules known as "urban grime." Chemical reactions that occur in this complex milieu can affect air and water quality. Now, researchers reporting in

Scientists have previously analyzed lab-prepared urban grime, as well as samples collected from cities, but they still don't have a complete understanding of what's in the material, or how it varies by location. Some components can react with other molecules in the grime or air, which could affect what gets released into the atmosphere or into the water when it rains. To better understand these processes, Tara Kahan and colleagues wanted to investigate the physical properties, light absorption and composition of urban grime samples collected from Syracuse, New York, and Scranton, Pennsylvania.The researchers collected samples of urban grime from Syracuse by placing vertical quartz plates outdoors for 30 days and then analyzed the surfaces. Although urban grime was long thought to be predominantly a film, the samples showed collections of particles, rather than a uniform film, consistent with evidence from other recent studies. In different experiments, the team scraped grime from wet exterior surfaces of windows in both cities and analyzed their compositions. The results were similar to those reported from other cities in Canada and Europe, but there were differences in specific ions. For example, higher chloride levels were found in North American cities, which could be from the use of road salt in the winter, whereas higher sulfate levels were reported in some European cities, likely because of coal combustion. The team also observed that urban grime absorbed light at wavelengths found in sunlight, which suggests that the sun could speed up or slow down chemical reactions that affect air and water quality in cities.

Pollution

September 29, 2020

https://www.sciencedaily.com/releases/2020/09/200929130301.htm

Many ventilation systems may increase risk of COVID-19 exposure, study suggests

Ventilation systems in many modern office buildings, which are designed to keep temperatures comfortable and increase energy efficiency, may increase the risk of exposure to the coronavirus, particularly during the coming winter, according to research published in the

A team from the University of Cambridge found that widely-used 'mixing ventilation' systems, which are designed to keep conditions uniform in all parts of the room, disperse airborne contaminants evenly throughout the space. These contaminants may include droplets and aerosols, potentially containing viruses.The research has highlighted the importance of good ventilation and mask-wearing in keeping the contaminant concentration to a minimum level and hence mitigating the risk of transmission of SARS-CoV-2, the virus that causes COVID-19.The evidence increasingly indicates that the virus is spread primarily through larger droplets and smaller aerosols, which are expelled when we cough, sneeze, laugh, talk or breathe. In addition, the data available so far indicate that indoor transmission is far more common than outdoor transmission, which is likely due to increased exposure times and decreased dispersion rates for droplets and aerosols."As winter approaches in the northern hemisphere and people start spending more time inside, understanding the role of ventilation is critical to estimating the risk of contracting the virus and helping slow its spread," said Professor Paul Linden from Cambridge's Department of Applied Mathematics and Theoretical Physics (DAMTP), who led the research."While direct monitoring of droplets and aerosols in indoor spaces is difficult, we exhale carbon dioxide that can easily be measured and used as an indicator of the risk of infection. Small respiratory aerosols containing the virus are transported along with the carbon dioxide produced by breathing, and are carried around a room by ventilation flows. Insufficient ventilation can lead to high carbon dioxide concentration, which in turn could increase the risk of exposure to the virus."The team showed that airflow in rooms is complex and depends on the placement of vents, windows and doors, and on convective flows generated by heat emitted by people and equipment in a building. Other variables, such as people moving or talking, doors opening or closing, or changes in outdoor conditions for naturally ventilated buildings, affect these flows and consequently influence the risk of exposure to the virus.Ventilation, whether driven by wind or heat generated within the building or by mechanical systems, works in one of two main modes. Mixing ventilation is the most common, where vents are placed to keep the air in a space well mixed so that temperature and contaminant concentrations are kept uniform throughout the space.The second mode, displacement ventilation, has vents placed at the bottom and the top of a room, creating a cooler lower zone and a warmer upper zone, and warm air is extracted through the top part of the room. As our exhaled breath is also warm, most of it accumulates in the upper zone. Provided the interface between the zones is high enough, contaminated air can be extracted by the ventilation system rather than breathed in by someone else. The study suggests that when designed properly, displacement ventilation could reduce the risk of mixing and cross-contamination of breath, thereby mitigating the risk of exposure.As climate change has accelerated since the middle of the last century, buildings have been built with energy efficiency in mind. Along with improved construction standards, this has led to buildings that are more airtight and more comfortable for the occupants. In the past few years however, reducing indoor air pollution levels has become the primary concern for designers of ventilation systems."These two concerns are related, but different, and there is tension between them, which has been highlighted during the pandemic," said Dr Rajesh Bhagat, also from DAMTP. "Maximising ventilation, while at the same time keeping temperatures at a comfortable level without excessive energy consumption is a difficult balance to strike."In light of this, the Cambridge researchers took some of their earlier work on ventilation for efficiency and reinterpreted it for air quality, in order to determine the effects of ventilation on the distribution of airborne contaminants in a space."In order to model how the coronavirus or similar viruses spread indoors, you need to know where people's breath goes when they exhale, and how that changes depending on ventilation," said Linden. "Using these data, we can estimate the risk of catching the virus while indoors."The researchers explored a range of different modes of exhalation: nasal breathing, speaking and laughing, each both with and without a mask. By imaging the heat associated with the exhaled breath, they could see how it moves through the space in each case. If the person was moving around the room, the distribution of exhaled breath was markedly different as it became captured in their wake."You can see the change in temperature and density when someone breathes out warm air -- it refracts the light and you can measure it," said Bhagat. "When sitting still, humans give off heat, and since hot air rises, when you exhale, the breath rises and accumulates near the ceiling."Their results show that room flows are turbulent and can change dramatically depending on the movement of the occupants, the type of ventilation, the opening and closing of doors and, for naturally ventilated spaces, changes in outdoor conditions.The researchers found that masks are effective at reducing the spread of exhaled breath, and therefore droplets."One thing we could clearly see is that one of the ways that masks work is by stopping the breath's momentum," said Linden. "While pretty much all masks will have a certain amount of leakage through the top and sides, it doesn't matter that much, because slowing the momentum of any exhaled contaminants reduces the chance of any direct exchange of aerosols and droplets as the breath remains in the body's thermal plume and is carried upwards towards the ceiling. Additionally, masks stop larger droplets, and a three-layered mask decreases the amount of those contaminants that are recirculated through the room by ventilation."The researchers found that laughing, in particular, creates a large disturbance, suggesting that if an infected person without a mask was laughing indoors, it would greatly increase the risk of transmission."Keep windows open and wear a mask appears to be the best advice," said Linden. "Clearly that's less of a problem in the summer months, but it's a cause for concern in the winter months."The team are now working with the Department for Transport looking at the impacts of ventilation on aerosol transport in trains and with the Department for Education to assess risks in schools this coming winter.

Pollution

September 29, 2020

https://www.sciencedaily.com/releases/2020/09/200929123715.htm

Are China's pollution remediation efforts making the planet warmer?

A 10-year effort by China to improve air quality and reduce pollution-related health risks has caused warming in areas across the northern hemisphere, according to new work published in

Aerosols are tiny particles that are spewed into the atmosphere by human activities, such as burning coal and wood, or by geological phenomena, like volcanos. Their negative effects on air quality can damage human health and agricultural productivity.Similar to how the aerosols emitted in a volcanic eruption can cause global temperatures to drop, some aerosols from human activity also have a cooling effect on the climate. Unlike greenhouse gases, which induce global warming by trapping heat in the atmosphere, aerosol particles can cause sunlight to be reflected away from the planet either directly or by interacting with clouds."This means that some of the effects of global warming are being masked by aerosol pollution," explained lead author, Carnegie's Yixuan Zheng.Between 2006 and 2017, the Chinese government implemented clean-air policies to reduce the public health risks of aerosol pollutants like sulfate, a cooling agent. These efforts have possibly saved as many as half a million lives a year.Zheng, along with Carnegie colleague Ken Caldeira, UC Irvine's Dan Tong and Steven Davis, and Qiang Zhang of Tsinghua University, set out to investigate how these aerosol reductions have affected the global climate.They applied a sophisticated model based on atmospheric and oceanic systems over a 100-year period, which revealed that China's pollution-reduction policies might have unmasked about 0.1 degrees Celsius (0.2 degrees Fahrenheit) of greenhouse-gas-induced warming throughout the northern hemisphere -- not just in China itself."The health risks associated with particulate pollution are very serious and mitigation efforts are unquestionably a good thing," Caldeira said. "But it's also important to understand how ongoing and future efforts to improve air quality will create additional challenges in the international fight against climate change."

Pollution

September 29, 2020

https://www.sciencedaily.com/releases/2020/09/200929123347.htm

Achieving clean air for all is possible, experts say

Air pollution is currently the largest environmental risk factor for human health globally and can be linked to several million cases of premature deaths every year. A new study however shows that it is possible to achieve clean air worldwide with fundamental transformations of today's practices in many sectors, supported by strong political will.

There is strong scientific evidence that air pollution causes negative health impacts even below the present World Health Organization (WHO) guideline values, especially for fine particles (PM2.5). In fact, the current WHO guideline value for PM2.5 -- which is exceeded by more than a factor of 10 in many parts of the world, especially in developing countries -- is often considered unattainable.The new study, published in The authors identified key factors that contributed to historic air pollution trends in different world regions, outlined conceivable ranges of their future development, and examined their interplay on global air quality in the next decades. Their efforts resulted in a first integrated perspective on achieving clean air around the world by combining different policy areas beyond air pollution."Policy interventions were instrumental in decoupling energy-related air pollution from economic growth in the past, and further interventions will determine future air quality," explains lead author and IIASA Air Quality and Greenhouse Gases Program Director, Markus Amann. "Theoretically, a portfolio of ambitious policy interventions could bring ambient PM2.5 concentrations below the WHO air quality guideline in most parts of the world, except in areas where natural sources such as soil dust, contribute major shares to, or even exceed the current guideline value."Achieving clean air, which would save millions of premature deaths annually, needs integration over multiple policy domains, including environmental policies focusing on pollution controls, energy and climate policies, policies to transform the agricultural production system, and policies to modify human food consumption patterns. However, the authors emphasize that none of these policy areas alone can deliver clean air, and interventions need to be coordinated across sectors. In addition, such policy interventions would simultaneously deliver a wide range of benefits on other policy priorities, while also making substantial contributions to human development in terms of the Sustainable Development Goals."Even if WHO air quality standards are currently exceeded by more than a factor of 10 in many parts of the world, clean air is achievable globally with enhanced political will. The required measures, in addition to their local health benefits, would also contribute to the long-term transformational changes that are required for global sustainable development," Amann concludes.

Pollution

September 28, 2020

https://www.sciencedaily.com/releases/2020/09/200928152913.htm

Plastic-eating enzyme 'cocktail' heralds new hope for plastic waste

The scientists who re-engineered the plastic-eating enzyme PETase have now created an enzyme 'cocktail' which can digest plastic up to six times faster.

A second enzyme, found in the same rubbish dwelling bacterium that lives on a diet of plastic bottles, has been combined with PETase to speed up the breakdown of plastic.PETase breaks down polyethylene terephthalate (PET) back into its building blocks, creating an opportunity to recycle plastic infinitely and reduce plastic pollution and the greenhouse gases driving climate change.PET is the most common thermoplastic, used to make single-use drinks bottles, clothing and carpets and it takes hundreds of years to break down in the environment, but PETase can shorten this time to days.The initial discovery set up the prospect of a revolution in plastic recycling, creating a potential low-energy solution to tackle plastic waste. The team engineered the natural PETase enzyme in the laboratory to be around 20 percent faster at breaking down PET.Now, the same trans-Atlantic team have combined PETase and its 'partner', a second enzyme called MHETase, to generate much bigger improvements: simply mixing PETase with MHETase doubled the speed of PET breakdown, and engineering a connection between the two enzymes to create a 'super-enzyme', increased this activity by a further three times.The study is published in the journal The team was co-led by the scientists who engineered PETase, Professor John McGeehan, Director of the Centre for Enzyme Innovation (CEI) at the University of Portsmouth, and Dr Gregg Beckham, Senior Research Fellow at the National Renewable Energy Laboratory (NREL) in the US.Professor McGeehan said: "Gregg and I were chatting about how PETase attacks the surface of the plastics and MHETase chops things up further, so it seemed natural to see if we could use them together, mimicking what happens in nature."Our first experiments showed that they did indeed work better together, so we decided to try to physically link them, like two Pac-men joined by a piece of string."It took a great deal of work on both sides of the Atlantic, but it was worth the effort -- we were delighted to see that our new chimeric enzyme is up to three times faster than the naturally evolved separate enzymes, opening new avenues for further improvements."The original PETase enzyme discovery heralded the first hope that a solution to the global plastic pollution problem might be within grasp, though PETase alone is not yet fast enough to make the process commercially viable to handle the tons of discarded PET bottles littering the planet.Combining it with a second enzyme, and finding together they work even faster, means another leap forward has been taken towards finding a solution to plastic waste.PETase and the new combined MHETase-PETase both work by digesting PET plastic, returning it to its original building blocks. This allows for plastics to be made and reused endlessly, reducing our reliance on fossil resources such as oil and gas.Professor McGeehan used the Diamond Light Source, in Oxfordshire, a synchrotron that uses intense beams of X-rays 10 billion times brighter than the Sun to act as a microscope powerful enough to see individual atoms. This allowed the team to solve the 3D structure of the MHETase enzyme, giving them the molecular blueprints to begin engineering a faster enzyme system.The new research combined structural, computational, biochemical and bioinformatics approaches to reveal molecular insights into its structure and how it functions. The study was a huge team effort involving scientists at all levels of their careers.One of the most junior authors, Rosie Graham, a joint Portsmouth CEI-NREL PhD student said: "My favourite part of research is how the ideas start, whether it's over coffee, on a train commute or when passing in the university corridors it can really be at any moment."It's a really great opportunity to learn and grow as part of this UK-USA collaboration and even more so to contribute another piece of the story on using enzymes to tackle some of our most polluting plastics."The Centre for Enzyme Innovation takes enzymes from the natural environment and, using synthetic biology, adapts them to create new enzymes for industry.

Pollution

September 25, 2020

https://www.sciencedaily.com/releases/2020/09/200925113445.htm

Tree rings show scale of Arctic pollution is worse than previously thought

The largest-ever study of tree rings from Norilsk in the Russian Arctic has shown that the direct and indirect effects of industrial pollution in the region and beyond are far worse than previously thought.

An international team of researchers, led by the University of Cambridge, has combined ring width and wood chemistry measurements from living and dead trees with soil characteristics and computer modelling to show that the damage done by decades of nickel and copper mining has not only devastated local environments, but also affected the global carbon cycle.The extent of damage done to the boreal forest, the largest land biome on Earth, can be seen in the annual growth rings of trees near Norilsk where die off has spread up to 100 kilometres. The results are reported in the journal Norilsk, in northern Siberia, is the world's northernmost city with more than 100,000 people, and one of the most polluted places on Earth. Since the 1930s, intensive mining of the area's massive nickel, copper and palladium deposits, combined with few environmental regulations, has led to severe pollution levels. A massive oil spill in May 2020 has added to the extreme level of environmental damage in the area.Not only are the high level of airborne emissions from the Norilsk industrial complex responsible for the direct destruction of around 24,000 square kilometres of boreal forest since the 1960s, surviving trees across much of the high-northern latitudes are suffering as well. The high pollution levels cause declining tree growth, which in turn have an effect of the amount of carbon that can be sequestered in the boreal forest.However, while the link between pollution and forest health is well-known, it has not been able to explain the 'divergence problem' in dendrochronology, or the study of tree rings: a decoupling of tree ring width from rising air temperatures seen since the 1970s.Using the largest-ever dataset of tree rings from both living and dead trees to reconstruct the history and intensity of Norilsk's forest dieback, the researchers have shown how the amount of pollution spewed into the atmosphere by mines and smelters is at least partially responsible for the phenomenon of 'Arctic dimming', providing new evidence to explain the divergence problem."Using the information stored in thousands of tree rings, we can see the effects of Norilsk's uncontrolled environmental disaster over the past nine decades," said Professor Ulf Büntgen from Cambridge's Department of Geography, who led the research. "While the problem of sulphur emissions and forest dieback has been successfully addressed in much of Europe, for Siberia, we haven't been able to see what the impact has been, largely due to a lack of long-term monitoring data."The expansion of annually-resolved and absolutely dated tree ring width measurements compiled by the paper's first author Alexander Kirdyanov, along with new high-resolution measurements of wood and soil chemistry, allowed the researchers to quantify the extent of Norilsk's devastating ecosystem damage, which peaked in the 1960s."We can see that the trees near Norilsk started to die off massively in the 1960s due to rising pollution levels," said Büntgen. "Since atmospheric pollution in the Arctic accumulates due to large-scale circulation patterns, we expanded our study far beyond the direct effects of Norilsk's industrial sector and found that trees across the high-northern latitudes are suffering as well."The researchers used a process-based forward model of boreal tree growth, with and without surface irradiance forcing as a proxy for pollutants, to show that Arctic dimming since the 1970s has substantially reduced tree growth.Arctic dimming is a phenomenon caused by increased particulates in the Earth's atmosphere, whether from pollution, dust or volcanic eruptions. The phenomenon partially blocks out sunlight, slowing the process of evaporation and interfering with the hydrological cycle.Global warming should be expected to increase the rate of boreal tree growth, but the researchers found that as the pollution levels peaked, the rate of tree growth in northern Siberia slowed. They found that the pollution levels in the atmosphere diminished the trees' ability to turn sunlight into energy through photosynthesis, and so they were not able to grow as quickly or as strong as they would in areas with lower pollution levels."What surprised us is just how widespread the effects of industrial pollution are -- the scale of the damage shows just how vulnerable and sensitive the boreal forest is," said Büntgen. "Given the ecological importance of this biome, the pollution levels across the high-northern latitudes could have an enormous impact on the entire global carbon cycle."

Pollution

September 25, 2020

https://www.sciencedaily.com/releases/2020/09/200925113436.htm

New way of analyzing soil organic matter will help predict climate change

A new way of analyzing the chemical composition of soil organic matter will help scientists predict how soils store carbon -- and how soil carbon may affect climate in the future, says a Baylor University researcher.

A study by scientists from Iowa State University and Baylor University, published in the academic journal Researchers analyzed samples of 42 soils from archives of the National Ecological Observatory Network and samples taken from additional sites, representing all of the major soil types on the continent.The soils were analyzed by William C. Hockaday, Ph.D., associate professor of geosciences at Baylor University, and visiting scientist Chenglong Ye, a postdoctoral scientist at Nanjing Agricultural University, in the Molecular Biogeochemistry Lab at Baylor. They used a technique called nuclear magnetic resonance spectroscopy, which allowed them to analyze the chemical structure and composition of natural organic molecules in the soil."Soils are a foundation of society by providing food, clean water and clean air," Hockaday said. "Soils also have a major role in climate change as one of the largest reservoirs of carbon on the planet. Even so, the chemical makeup of this carbon has been debated by scientists for over 100 years.""With this study, we wanted to address the questions of whether organic matter is chemically similar across environments or if it varies predictably across environments," said Steven Hall, Ph.D., the study's lead author and assistant professor of ecology, evolution and organismal biology at Iowa State.The study revealed patterns in soil organic matter chemistry that held true across climates. Understanding these patterns, or rules for how and why organic matter forms and persists in soil, will help scientists predict how soils in various ecosystems store carbon. Carbon can contribute to climate change when released from soil into the atmosphere as a greenhouse gas. An improved understanding of what kinds of soil carbon exist in different environments can paint a clearer picture of how soil carbon may affect climate and how future climate changes may affect the reservoir of soil carbon, researchers said."This study brought together a strong team of scientists, and for me, it was the first time to consider chemical patterns at a continental scale," Hockaday said. "It is exciting and gratifying when you inform a long-standing debate and offer an explanation of a major pattern that exists in nature."

Pollution

September 25, 2020

https://www.sciencedaily.com/releases/2020/09/200925113358.htm

New knowledge about what causes thunderstorms and cloud bursts

Thunderstorms are weather disturbances characterized by concentrations of thunder, lightning and fierce winds.

When they accumulate in clusters, these storms are often accompanied by violent cloud bursts and flooding, which can devastate the areas affected.Denmark is no stranger to this phenomenon. In 2011, large parts of Copenhagen were submerged by deluges that lead to roughly 6 billion kroner in damages reported to insurance companies.In a new study, researchers from the University of Copenhagen shed light on one particular mechanism that has the potential to spawn powerful thunderstorms and cloud bursts:"We conclude that the atmosphere's ability to generate large thunderstorms is influenced, among other things, by the difference between the temperature of the earth's surface during the night versus during the day. If the difference is great, we see more thunderstorms, and subsequently, more cloud bursts," explains Jan Olaf Härter, an associate professor at the University of Copenhagen's Niels Bohr Institute.Along with his department colleagues, Härter used computer simulations to study the occurrence of so-called mesoscale convection systems -- particularly powerful thunderstorms that spread out over areas of 100 kilometers or more.While these types of thunderstorms occur mainly in the tropics, they are also relevant in the Danish context."If summertime temperatures in Denmark continue to increase, I would not be surprised if we experience more thunderstorms and cloud bursts. And this is exactly what some climate models predict will occur within the next 20-30 years," says Jan Olaf Härter.Thunder occurs when warm, moist surface level air rises into weather and meets cooler air higher up in the atmosphere.This destabilizes the air above it even more and creates convection, which transports the warm air even higher.It's like a pot of boiling water -- heated water at the bottom of a pot rises upwards and bubbles to the surface. The same occurs with thunderstorms."As warm air is shot up into the atmosphere, it meets with colder air and condenses, i.e., it forms clouds and raindrops. Consequently, thunderstorms are usually followed by dense rain and cloudbursts," explains Silas Boye Nissen, a PhD student at the Niels Bohr Institute, and one of the researchers behind the study.The researchers conclude that the risk of major thunderstorms and cloud bursts is influenced by differences between the earth's surface temperature at night and day.When the temperature difference is large, the risk of severe thunderstorms increases. And while scientists can't yet say for sure what affects the temperature differences, they propose a cautious hypothesis.The difference between day- and nighttime surface temperatures is dependent upon the moisture content of soil.If soil is moist, temperature differences are reduced; "Like a swimming pool or a sea that moderates day- and nighttime temperatures," explains Härter.If, on the other hand, soil is dry, high daytime temperatures will decrease significantly overnight, as there is not enough moisture in the soil to absorb the heat.Danish thunderstorms typically cover areas of about 10 kilometers, while tropical thunderstorms can spread over areas of 100 kilometers or more.The reason why thunderstorms can be so powerful, in addition to large day and nighttime temperature variations at the earth's surface, also relates to a self-reinforcing mechanism."When differences in air temperature create clouds and intense rain, the rain uses up lots of energy on its way down as it slowly evaporates. As this occurs, each raindrop creates a pocket of cold air around it. As these pockets of cold air collide with other cold air pockets, of other weather systems, more clouds, rain and thunder are formed. This results in a self-reinforcing effect," explains Silas Boye Nissen, who concludes:Torrential rain from cloud bursts often causes damage to homes and jeopardizes people's lives. As such, it is important to keep researching the causes of extreme weather phenomena."

Pollution

September 24, 2020

https://www.sciencedaily.com/releases/2020/09/200924135323.htm

Unusual climate conditions influenced WWI mortality and subsequent influenza pandemic

Scientists have spotted a once-in-a-century climate anomaly during World War I that likely increased mortality during the war and the influenza pandemic in the years that followed.

Well-documented torrential rains and unusually cold temperatures affected the outcomes of many major battles on the Western Front during the war years of 1914 to 1918. Most notably, the poor conditions played a role in the battles of Verdun and the Somme, during which more than one million soldiers were killed or wounded.The bad weather may also have exacerbated the influenza pandemic that claimed 50 to 100 million lives between 1917 and 1919, according to the new study. Scientists have long studied the spread of the H1N1 influenza strain that caused the pandemic, but little research has focused on whether environmental conditions played a role.In a new study in AGU's journal Mallard ducks likely stayed put in western Europe in the autumns of 1917 and 1918 because of the bad weather, rather than migrating northeast to Russia as they normally do, according to the new study. This kept them close to military and civilian populations and may have allowed the birds to transfer a particularly virulent strain of H1N1 influenza to humans through bodies of water. Listen to the latest episode of AGU's podcast Third Pod from the Sun to learn more about climate and pandemics.The findings help scientists better understand the factors that contributed to making the war and pandemic so deadly, according to Alexander More, a climate scientist and historian at the Harvard University/Climate Change Institute, associate professor of environmental health at Long Island University and lead author of the new study."I'm not saying that this was 'the' cause of the pandemic, but it was certainly a potentiator, an added exacerbating factor to an already explosive situation," More said."It's interesting to think that very heavy rainfall may have accelerated the spread of the virus," said Philip Landrigan, director of the Global Public Health Program at Boston College who was not connected to the new study. "One of the things we've learned in the COVID pandemic is that some viruses seem to stay viable for longer time periods in humid air than in dry air. So it makes sense that if the air in Europe were unusually wet and humid during the years of World War I, transmission of the virus might have been accelerated."The rainy, cold, muddy landscapes of the Western Front are well documented by historians. Poet Mary Borden described it as "the liquid grave of our armies" in her poem "The Song of the Mud" about 1916's Battle of the Somme.Historical accounts of early battles in France describe how the intense rain affected British, French and German troops. Newly dug trenches and tunnels filled with rainwater; muddy fields slowed the movement of troops during the day; and cold nighttime temperatures caused thousands to endure frostbite. However, little research has been done on the environmental conditions that may have caused the torrential rains and unusual cold.In the new study, More and his colleagues reconstructed the environmental conditions over Europe during the war using data from an ice core taken from the Alps. They then compared the environmental conditions to historical records of deaths during the war years.They found mortality in Europe peaked three times during the war, and these peaks occurred during or soon after periods of cold temperatures and heavy rain caused by extremely unusual influxes of ocean air in the winters of 1915, 1916 and 1918."Atmospheric circulation changed and there was much more rain, much colder weather all over Europe for six years," More said. "In this particular case, it was a once in a 100-year anomaly."The new ice core record corroborates historical accounts of torrential rain on battlefields of the Western Front, which caused many soldiers to die from drowning, exposure, pneumonia and other infections.Interestingly, the results suggest the bad weather may have kept mallard ducks and other migratory birds in Europe during the war years, where they could easily transmit influenza to humans by water contaminated with their fecal droppings. Mallard ducks are the main animal reservoir of H1N1 flu viruses and as many as 60 percent of mallard ducks can be infected with H1N1 every year. Previous research has shown that migratory patterns of mallards and other birds are disrupted during bouts of unusual weather."Mallards have been shown to be very sensitive to climate anomalies in their migration patterns," More said. "So it is likely is that they stayed put for much of that period."The first wave of H1N1 influenza infection in Europe occurred in the spring of 1918, most likely originating among allied troops arriving in France from Asia in the fall and winter of 1917, according to previous research. The new study found the deadliest wave of the pandemic in Europe began in the autumn of 1918, closely following a period of heavy precipitation and cold temperatures."These atmospheric reorganizations happen and they affect people," More said. "They affect how we move, how much water is available, what animals are around. Animals bring their own diseases with them in their movements, and their migrations are due to the environment and how it changes, or how we change it.""I think it's a very credible, provocative study that makes us think in new ways about the interplay between infectious diseases and the environment," Landrigan said.

Pollution

September 24, 2020

https://www.sciencedaily.com/releases/2020/09/200924114124.htm

Air pollution leads to increase in electricity usage

High levels of air pollution are forcing people inside to consume more electricity, subsequently causing even greater environmental problems by increasing greenhouse gas emissions.

This is according to a new study from researchers at Cardiff University who have shown that the effects are seen more in lower-income families and those from ethnic minority backgrounds.The team say the results should encourage decision makers to think about how policy can prevent inequality from widening in terms of both health risks and financial hardships.The study, which has been published in the journal The Phoenix metropolitan area has the highest air pollution levels in the United States, with pollution being generated from both natural sources, such as dust storms, and human activities such as energy generation and transport.The energy consumption data from the buildings in Phoenix was compared to levels of pollution in the area, allowing the researchers to tell whether households with distinct income levels or from various ethnic groups responded to air pollution differently.The results showed that higher levels of pollution were associated with higher electricity consumption in residential buildings, with increases mainly happening in the daytime.Higher pollution levels also resulted in higher electricity consumption in commercial buildings in the retail and recreation industries."Our results indicate that when air pollution levels are high, people tend to reduce travelling and shift to indoor activities, which lead to more electricity consumption in general, whether it be from heating, cooling and lighting or the increase use of appliances" said lead author of the study Dr Pan He from Cardiff University's School of Earth and Ocean Sciences."Lower-income or Hispanic consumers experienced a larger increase, possibly because they have low energy efficiency in their homes and are more exposed to air pollution."The researchers also examined the impact of high levels of air pollution on energy supplies, specifically solar panels.It is believed that solar panels can lose their efficiency as air pollution not only absorbs and scatters the sunlight in the air, but also gets deposited on the surface of the panels which hampers their power generation.Indeed, the results showed that air pollution reduced the power generated by solar panels in both the residential and commercial buildings, with the latter less affected potentially because the panels are better maintained and cleaned."Our findings show the importance of considering the interactions and feedbacks of consumer behavior and solar energy systems to air pollution issues," Dr He continued."A cost-benefit analysis when accounting for the damages presented in this paper could produce larger welfare gains from pollution control policies. Meanwhile, it is critical to reduce the socio-economic vulnerability in adapting to air pollution, which can be achieved by improving the energy efficiency in the homes of specific income and ethnic groups."

Pollution

September 23, 2020

https://www.sciencedaily.com/releases/2020/09/200923124758.htm

UK lockdown and air pollution: Nitrogen dioxide halved but sulfur dioxide doubled

A University of Liverpool study of air pollution in the UK during the first 100 days of lockdown has revealed that whilst nitrogen oxide levels were cut by half, levels of sulphur dioxide increased by over 100%.

Researchers from the University's School of Environmental Sciences analysed data from the Department for Environment, Food & Rural Affairs (DEFRA) air-quality sensors and UK Met Office stations to see how lockdown measures had affected levels of nitrogen dioxide, sulphur dioxide, particle matter (PM2.5) and ozone, and compare it to data from the past seven years.The study revealed that during this period (from 23rd March to 13 June 2020) nitrogen dioxide (NO2) levels were cut by half which would relate to the reduction in vehicle emissions. More surprisingly, though, the analysis found that levels of sulphur dioxide (SO2), typically created by UK industry but in sharp decline, were more than double that of previous years.Researchers also explored the localised effects of lockdown on air-quality, on seven large UK cities: London, Glasgow, Belfast, Birmingham, Manchester, Newcastle and Liverpool.This revealed that NO2 levels in all of the cities reduced on average between 37 -- 41% although it was these reductions were slightly greater in Glasgow declining by 44%. However, northern cities were found to experience greater increases in sulphur dioxide.Lockdown in the UK came into effect on 23 March 2020 when the Prime minister, Boris Johnson, told the country that people 'must' stay at home and certain businesses must close.This resulted in the significant reduction in motor vehicle usage with the first day of lockdown seeing a reduction to 69% of normal. This reached a low of 23% on 13 April before steadily increasing back to 77% 100 days after the lockdown. The first 100 days of lockdown also coincided with higher temperature and less humidity.Lecturer in contemporary and dynamic processes, Dr Jonny Higham, who led the study said: "The results of our analysis are surprising. It is evident that the reduction in motor vehicles and human activity had a substantial impact on air quality as demonstrated by the reduction in nitrogen oxide. However, although it reduced one pollutant there has been a big increase in another pollutant."We think these changes could be driven by an in-balance in the complex air chemistry near to the surface exacerbated by the meteorological conditions in particularly low humidity levels and changes in pollutions concentrations."It is important to note that the complex and relatively stable air composition in the near surface layer can be disrupted in a short period of time by the significant reduction of primary emissions from human activities. For the case of UK, getting cleaner air from a large NO2 reduction may not be as straightforward as it seems."

Pollution

September 23, 2020

https://www.sciencedaily.com/releases/2020/09/200923124615.htm

First evidence that air pollution particles and metals are reaching the placenta

Pollution particles, including metals, have been found in the placentas of fifteen women in London, according to research led by Queen Mary University of London.

The study, funded by Barts Charity and published in the journal The researchers say that further research is needed to fully define the direct effect that pollution particles may have on the developing fetus.Lead author Professor Jonathan Grigg from Queen Mary University of London said: "Our study for the first time shows that inhaled carbon particulate matter in air pollution, travels in the blood stream, and is taken up by important cells in the placenta. We hope that this information will encourage policy makers to reduce road traffic emissions in this post lock down period."Dr Norrice Liu from Queen Mary University of London added: "Pollution levels in London often exceed annual limits and we know that there is a link between maternal exposure to high pollution levels and problems with the fetus, including risk of low birthweight. However, until now we had limited insight into how that might occur in the body."Placentas from 15 consenting healthy women were donated to the study following the birth of their children at The Royal London Hospital. Pollution exposure was determined in 13 of the women, all of whom had exposure above the annual mean WHO limit for particulate matter. The cells in the placentas were analysed using a range of techniques including light and electron microscopy, x-rays and magnetic analyses.Black particles that closely resembled particulate matter from pollution were found in placental cells from all fifteen women and these appeared in an average of 1 per cent of the cells which were analysed.The majority of particles found in the placental cells were carbon-based, but researchers also found trace amounts of metals including silica, phosphorus, calcium, iron and chromium, and more rarely, titanium, cobalt, zinc and cerium.Analysis of these nanoparticles strongly suggests that they predominantly originated from traffic-related sources. Many of these metals are associated with fossil fuel combustion, arising from fuel and oil additives, and vehicle brake-wear.Dr Lisa Miyashita from Queen Mary University of London said: "We have thought for a while that maternal inhalation could potentially result in pollution particles travelling to the placenta once inhaled. However, there are many defence mechanisms in the lung that prevent foreign particles from travelling elsewhere, so it was surprising to identify these particles in the placental cells from all 15 of our participants."Fiona Miller Smith, Chief Executive of Barts Charity said: "This is an incredibly important study and immensely relevant to mums-to-be in our local community, indeed in any urban community anywhere in the world."In the current climate it can be hard to see beyond COVID and so we are particularly proud to have funded this vital work and truly hope that it will lead to greater awareness of the risks of pollution to the unborn child."The study involved researchers from University of Lancaster, Barts Health NHS Trust, University of Manchester, Central Manchester University Hospital NHS Foundation Trust, King's College London, University of Birmingham, University of Oxford and University of Leeds.

Pollution

September 21, 2020

https://www.sciencedaily.com/releases/2020/09/200921111644.htm

Mirror-like photovoltaics get more electricity out of heat

New heat-harnessing "solar" cells that reflect 99% of the energy they can't convert to electricity could help bring down the price of storing renewable energy as heat, as well as harvesting waste heat from exhaust pipes and chimneys.

The energy storage application, known informally as a "sun in a box," stores extra wind and solar power generation in a heat bank."This approach to grid-scale energy storage is receiving widespread interest because it is estimated to be ten-fold cheaper than using batteries," said Andrej Lenert, an assistant professor of chemical engineering.The "sun" itself in this approach is already low cost: a tank of molten silicon, for instance. The relatively expensive parts are the photovoltaic panels that turn the stored heat back into electricity.Compared to ordinary solar panels that turn light, rather than heat, into electricity, thermal photovoltaics need to be able to accept lower energy photons -- packets of light or heat -- because the heat source is at lower temperature than the sun. To maximize efficiency, engineers have been looking to reflect the photons that are too low-energy back into the heat bank. That way, the energy gets reabsorbed and has another chance to get packaged into an electricity-producing, higher-energy photon."It's a recycling job," said Steve Forrest, the Peter A. Franken Distinguished University Professor of Engineering and the Paul G. Goebel Professor of Engineering. "The energy emitted by the heat bank has over 100 chances to be absorbed by the solar cell before it gets lost."The conventional gold-backed thermophotovoltaic reflects 95% of light that it can't absorb -- not bad, but if 5% of the light is lost with each bounce, that light has on average 20 chances to be re-emitted in a photon with enough energy to be turned into electricity.Increasing the number of opportunities means one could potentially use cheaper solar cell materials that are choosier about what photon energies they'll accept. This has additional benefits: higher energy photons make higher energy electrons, which means higher voltages and less energy lost while getting the electricity out.In order to improve the reflectivity, the team added a layer of air between the semiconductor -- the material that converts the photons into electricity -- and the gold backing. The gold is a better reflector if the light hits it after traveling in air, rather than coming straight from the semiconductor. To minimize the degree to which the light waves cancel each other out, the thickness of the air layer must be similar to the wavelengths of the photonsInitially, electrical engineering and computer science doctoral student Dejiu Fan balked at the job of making such a cell. Fan explained that the thickness of the air layer had to be very precise -- within a few nanometers -- to reflect the lower energy photons. What's more, the fragile semiconductor film is only 1.5 micrometers (.0015 millimeters) thick, yet it needed to span over 70 micrometers of air between the 8-micrometer-wide gold beams."It was not clear at the beginning if this 'air bridge' structure, with such a long span and without any mechanical support in the middle, could be built with high precision and survive multiple harsh fabrication processes," Fan said.But he did it -- and remarkably quickly, Forrest said. Fan, working with Tobias Burger, a doctoral student in chemical engineering, and other collaborators, laid the gold beams onto the semiconductor. Then, they coated a silicon back plate with gold to make the mirror and cold-welded the gold beams to the gold backing. This way, the thickness of the gold beams could accurately control the height of the air-bridge, enabling the near-perfect mirroring.Lenert is already looking ahead to raising the efficiency further, adding extra "nines" to the percentage of photons reflected. For instance, raising the reflectivity to 99.9% would give heat 1,000 chances to turn into electricity.The study published in The research was funded by the Army Research Office and the National Science Foundation. Forrest is also a professor of electrical engineering and computer science, material science and engineering, and physics. The device was built in the Lurie Nanofabrication Facility.

Pollution

September 17, 2020

https://www.sciencedaily.com/releases/2020/09/200917181303.htm

Ecologists sound alarm on plastic pollution

Ecologists studying the prevalence of plastic pollution in aquatic ecosystems around the world are concerned after measuring the scale of human response needed to reduce future emissions and manage what's already floating around out there.

"Unless growth in plastic production and use is halted, a fundamental transformation of the plastic economy to a framework based on recycling is essential, where end-of-life plastic products are valued rather than becoming waste," says Chelsea Rochman, assistant professor in the Department of Ecology & Evolutionary Biology at the University of Toronto (U of T), and senior author of a study published in "Even if governments around the world meet their ambitious global commitments, and other countries join those efforts to curb plastic pollution, worldwide annual emissions to rivers, lakes and oceans could be as much as 53 million metric tonnes by the year 2030," says Stephanie Borrelle, Smith Postdoctoral Fellow at U of T and lead author on the study. "That's far beyond the 8 million metric tonnes amount that was declared unacceptable in 2015."The research by an international group of experts led by Rochman and Borrelle, consisted of an evaluation of the level of effort needed to achieve a global reduction target for plastic pollution of less than 8 million metric tonnes (MT).The group first estimated that 24-34 million MT of plastic emissions currently enter aquatic ecosystems every year. They then modelled future scenarios using existing mitigation strategies: reducing production of plastic waste (which includes bans), improving management of plastic waste that is produced, and continuous recovery (i.e., cleanup) from the environment.The researchers found that even with parallel efforts in all three solutions, the level of effort required within each is enormous:(1) a 25 -- 40% reduction in the production of plastic across all economies;(2) increasing the level of waste collection and management to at least 60% across all economies -- with a change from 6 -- 60% in low-income economies; (3) recovery of 40% of annual plastic emissions through cleanup efforts."To put that last number into people power, the cleanup alone would require at least 1 billion people participating in Ocean Conservancy's annual International Coastal Cleanup," says Borrelle. "This would be a Herculean task given this is 660 times the effort of the 2019 cleanup."The researchers note, however, that even if the prescribed effort is realized, the world remains locked into an unacceptable plastic future."The global community must coordinate a fundamental transformation of the plastics economy, one that reduces the amount of virgin plastic production, and reimagines how we make use and dispose of plastic materials," says Rochman.The research was supported by the National Science Foundation through the National Socio-Environmental Synthesis Center (SESYNC).

Pollution

September 17, 2020

https://www.sciencedaily.com/releases/2020/09/200917105324.htm

Climate change impacts astronomical observations

Climate changes associated with global warming can affect astronomical observations. That is the result of a study involving scientists from the University of Cologne. The international research team investigated a range of climate parameters at the Very Large Telescope (VLT) at the Paranal in the Atacama Desert in Chile, where the European Southern Observatory (ESO) operates its telescopes. Among other things, the team evaluated the data for temperature, wind speed and wind direction, and the water vapour content in the atmosphere over a period of several decades. This revealed an increase in temperatures above the world average and also increasing image blur due to air turbulence -- so-called seeing.

The study 'The impact of climate change on astronomical observations' was published in the current issue of The Cologne-based scientists Professor Dr Susanne Crewell and Christoph Böhm from the Institute of Geophysics and Meteorology were involved in the study. In the past, they had already explored various aspects of the past, present and future climate at the telescope's site in the framework of Collaborative Research Centre 1211 'Earth -- Evolution at the Dry Limit'. The first author of the article is Faustine Cantalloube from the Max Planck Institute for Astronomy in Heidelberg.The researchers investigated the extent to which climate change affects astronomy and in particular the quality of observations. The team focused on the Paranal Observatory in northern Chile because it has a whole range of environmental sensors that document local meteorological conditions. These measurements yielded one of the most comprehensive data sets over the last three decades at a largely untouched location.Based on this data set, astronomers, climate researchers, atmosphere scientists, and meteorologists joined forces to identify important meteorological parameters that play a role in the quality of astronomical observations. The data allowed them to analyse long-term trends over a period of more than thirty years to determine the impact of climate change on future observations. Using four examples, they showed how climate change is already affecting, or might affect the operation of an astronomical observatory in future. The VLT, operated by ESO, was served as an example.'The data showed a 1.5 ° C increase in near-ground temperature over the last four decades at the Paranal Observatory. This is slightly higher than the worldwide average of 1°C since the pre-industrial age,' said Susanne Crewell. Since the original telescope cooling system was not designed for such warm conditions, the quality of observations is increasingly endangered by more frequent turbulences -- a consequence of the rise in temperature. The expected rise of 4° C (the most pessimistic scenario of the ICCP climate simulations) within the next century thus has to be taken into account in the construction of the 39-metre Extremely Large Telescope (ELT) at a nearby site.In particular, astronomers face the challenge of a reduction in the so-called 'dome seeing', a reduction in resolution due to turbulence within the telescope dome. The researchers furthermore noticed an increase in turbulence in the air layer near the ground, making images blurred since cold and warm air layers with different refractive indices alternate more quickly. However, attributing this to climate change is difficult, since there were also constructional changes. The increase in wind shear in the upper troposphere in connection with the jet stream also leads to a so-called 'wind-driven halo'. This phenomenon appears when atmospheric turbulence conditions vary faster than the telescope's control system can correct them. This limits the contrast capabilities of the instrument and could potentially limit exoplanet studies. An increase in water vapour in the atmosphere moreover could lead to a reduction of the astronomical signal.Through their unique perspective on the universe, astronomers know that the origin of life on Earth was a complex process made possible only by the coincidence of extremely rare circumstances. There is no second Earth in our neighbourhood. For this reason, the current issue of

Pollution

September 16, 2020

https://www.sciencedaily.com/releases/2020/09/200916154851.htm

The persistence of plastic

The amount of synthetic microfiber we shed into our waterways has been of great concern over the last few years, and for good reason: Every laundry cycle releases in its wastewater tens of thousands of tiny, near-invisible plastic fibers whose persistence and accumulation can affect aquatic habitats and food systems, and ultimately our own bodies in ways we have yet to discover.

And according to researchers from UC Santa Barbara's Bren School of Environmental Science & Management, that's not the whole picture. In a new study published in the journal "The emissions of microfibers onto terrestrial environments -- that was a known process. But the magnitude of the issue was not well known," said Jenna Gavigan, who led the study, the first ever to examine the problem on a global scale.Using global datasets on apparel production, use and washing with emission and retention rates during washing, wastewater treatment and sludge management, Gavigan and colleagues estimate that 5.6 million metric tonnes (Mt) of synthetic microfibers have been emitted from apparel washing between 1950 and 2016, with 2.9 Mt finding their way into waterbodies and a combined 2.5 Mt emitted onto terrestrial environments (1.9 Mt) and landfilled (0.6 Mt)."If you look at the figures you can see the enormous growth in synthetic clothes production, and as a result, increased synthetic microfiber pollution," said industrial ecology professor and paper co-author Roland Geyer.Indeed, according to the paper, about half of the total synthetic microfiber emissions since 1950 (the dawn of synthetic fiber mass production) were generated in the last decade alone. Thanks in large part to the global appetite for fast fashion and its tendency toward cheaper, mass-producible synthetic fibers, as well as increased access to washing machines, our laundry is polluting not just the ocean, but the land, too.Where is it coming from, this enormous -- and until now, largely unnoticed -- mass of synthetic microfibers? It turns out that in the effort to keep them from getting in our waterways, these fibers are accumulating in the sludge of wastewater treatment plants."Wastewater treatment is not the end of the pollution," said industrial ecology professor Sangwon Suh, who also is a co-author on the study. With a roughly 95-99% removal efficiency, all but the tiniest microplastics are caught in the sludge, which is treated and turned into biosolids, and "predominantly used in land applications," as fertilizer and soil amendments."A smaller percentage goes to the landfill," Gavigan said. "The smallest percentage gets dumped into the ocean in some countries, and some of it is incinerated.""So then it becomes a terrestrial pollution issue," Geyer pointed out. "We just turned it into a different environmental pollution issue rather than having actually solved it."According to the researchers, preventing emissions at the source -- whether by using a microfiber capture device, selecting a gentler wash method, washing clothes less often or foregoing synthetic fabrics -- would be more effective at mitigating microfiber pollution than trying to capture the fibers after the wastewater is sent to the treatment plant.This sobering study has its roots in a 2016 Bren group project in which several graduate students, in research conducted for the outdoor apparel company Patagonia, sought to study the conditions that affect garment shedding. That undertaking focused primarily on the microfiber-laden effluent leaving the washing machine, and produced influential research that raised awareness of the synthetic microfiber problem.The collaboration also inspired a 2017 microfiber leadership summit co-hosted by the Bren School and the environmental organization Ocean Conservancy, in which more than 50 stakeholders, including representatives from industry, government, the research community, the apparel sector and environmental nonprofits convened to try to get their arms around the issue. The result? A road map based on a shared vision, and action items for each stakeholder to steer toward solutions."When it comes to microfiber pollution, these new findings show that the ocean has been the canary in the coal mine, and that plastic pollution is far more pervasive in our environment than originally thought," said Nick Mallos, senior director of Trash Free Seas® at the Ocean Conservancy. "Fortunately, simple and effective solutions -- like adding filters to washing machines -- exist. We urge manufacturers to make these modifications standard."This global assessment of synthetic microfiber emissions is part of a larger picture of microplastics in the environment that the researchers hope to fill in as they uncover the pathways these tiny fibers take. For instance, what other sources contribute these fibers to the environment? How do they move around and what systems may be affected? How do these microfibers interact with the biota of a region? Gaining answers to these and other questions could lead to practices that mitigate or prevent the effects of global synthetic microfiber pollution, even as consumption increases."There are huge unknowns," Suh said. "The amount of microplastics and microfibers that are generated is quite massive and continuing to rise, and if it continues there will be big changes, the consequences of which we are not yet sure. That's what makes it concerning."

Pollution

September 14, 2020

https://www.sciencedaily.com/releases/2020/09/200914212926.htm

NASA monitors carbon monoxide from California wildfires

NASA's Atmospheric Infrared Sounder (AIRS), aboard the Aqua satellite, captured carbon monoxide plumes coming from California wildfires last week. There were 28 major wildfires burning across the state as of Sept. 14. This includes the August Complex Fire, which started on Aug. 17 and has since burned over 471,000 acres, making it the largest fire on record in California.

The animation shows three-day averages of carbon monoxide concentrations around 3 miles (5 kilometers) up in the atmosphere between Sept. 6 and Sept. 14. The red and orange areas indicate regions with extremely high carbon monoxide concentrations of greater than 350 parts per billion by volume (ppbv). The more normal, background concentrations of carbon monoxide show up as yellow and green, with amounts between 30 and 50 ppbv.Released by the fires along with smoke and ash, carbon monoxide is a pollutant that can persist in the atmosphere for about a month and can be transported great distances. At the high altitude mapped in these images, the gas has little effect on the air we breathe; however, strong winds can carry it downwards to where it can significantly impact air quality. Carbon monoxide plays a role in both air pollution and climate change.The intense heat from the wildfires lofted the carbon monoxide high into the atmosphere, enabling detection by the AIRS instrument. The jet stream then blew the carbon monoxide plume eastward across the U.S. and over the Atlantic Ocean.AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU), senses emitted infrared and microwave radiation from Earth to provide a three-dimensional look at Earth's weather and climate. Working in tandem, the two instruments make simultaneous observations down to Earth's surface. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, three-dimensional map of atmospheric temperature and humidity, cloud amounts and heights, greenhouse gas concentrations and many other atmospheric phenomena. Launched into Earth orbit in 2002, the AIRS and AMSU instruments fly onboard NASA's Aqua spacecraft and are managed by NASA's Jet Propulsion Laboratory in Pasadena, California, under contract to NASA. JPL is a division of Caltech.The latest carbon monoxide data, as well as other information from NASA Earth-observing missions can be viewed at the fully interactive Eyes on the Earth (More information about AIRS can be found at:

Pollution

September 14, 2020

https://www.sciencedaily.com/releases/2020/09/200914112232.htm

Arctic transitioning to a new climate state

The fast-warming Arctic has started to transition from a predominantly frozen state into an entirely different climate, according to a comprehensive new study of Arctic conditions.

Weather patterns in the upper latitudes have always varied from year to year, with more or less sea ice, colder or warmer winters, and longer or shorter seasons of rain instead of snow. But the new research by scientists at the National Center for Atmospheric Research (NCAR) finds that the Arctic has now warmed so significantly that its year-to-year variability is moving outside the bounds of any past fluctuations, signaling the transition to a "new Arctic" climate regime."The rate of change is remarkable," said NCAR scientist Laura Landrum, the lead author of the study. "It's a period of such rapid change that observations of past weather patterns no longer show what you can expect next year. The Arctic is already entering a completely different climate than just a few decades ago."In the new study, Landrum and her co-author, NCAR scientist Marika Holland, find that Arctic sea ice has melted so significantly in recent decades that even an unusually cold year will no longer have the amount of summer sea ice that existed as recently as the mid-20th century. Autumn and winter air temperatures will also warm enough to enter a statistically distinct climate by the middle of this century, followed by a seasonal change in precipitation that will result in additional months in which rain will fall instead of snow.For the study, Landrum and Holland used hundreds of detailed computer simulations as well as observations of Arctic climate conditions. The vast amount of data enabled them to statistically define the climate boundaries of the "old Arctic" -- or how much variability can naturally occur from year to year -- and then to identify when human-caused warming will push the Arctic beyond those natural bounds and into a new climate.The future projections used for the study are based on a high-end scenario for future emissions of greenhouse gases, a trajectory known as RCP 8.5. The paper notes, however, that reduced emissions would lessen the extent of climate change in the Arctic.The shifting climate has wide-ranging enormous consequences for ecosystems, water resource management, flood planning, and infrastructure.The research was funded by the National Science Foundation, which is NCAR's sponsor, and the National Oceanic and Atmospheric Administration.  The far north is warming more rapidly than lower-latitude regions, which is due to a process known as Arctic amplification. This occurs because light-colored sea ice, which reflects heat back into space, is replaced by darker ocean water, which traps heat. In addition, relatively warm ocean waters are no longer shielded in the winter as effectively by the insulating properties of thick sea ice.The changes in Arctic climate are so profound that the average extent of sea ice in September, when it reaches its annual minimum, has dropped by 31% since the first decade of the satellite era (1979-88).Landrum and Holland wanted to determine if this decline shows that the Arctic climate has fundamentally changed. They also wanted to study changes to two other key aspects that are indicative of the frozen state of Arctic climate: air temperatures in the fall and winter, and the seasonal transition in precipitation from mostly snow to mostly rain.To answer these questions, they turned to multiple simulations from five of the world's leading climate models that have been used for an international research project known as the Coupled Model Intercomparison Project 5, or CMIP5. The large number of simulations enabled them to assemble a statistically significant picture of Arctic climate, allowing them to differentiate year-to-year natural climate variability from a transition to a new Arctic climate.The scientists compared the model output to observations, confirming that the models were accurately capturing past climate and therefore could reliably simulate future climate.Landrum and Holland then applied statistical techniques to determine when climatic changes exceeded the bounds of natural variability. For this last question, they identified a different climate as emerging when the 10-year average was at least two standard deviations away from the average of the climate in the decade 1950-59.In other words, if the sea ice extent changed so much that the average in, say, the 1990s was lower in 97.7% of all cases than the sea ice extent for any year in the 1950s, then the 1990s were defined as a new climate.When they applied these techniques to sea ice extent, they found that the Arctic has already entered a new climate. Each of the five models showed sea ice retreating so dramatically that a new climate for sea ice had emerged in the late 20th and early 21st centuries.Looking forward, they also found that the Arctic may start to experience largely ice-free conditions in the next several decades. Several of the models indicated that the Arctic could become mostly ice free for 3-10 months annually by the end of the century, based on a scenario of high greenhouse gas emissions.In terms of air temperatures, Landrum and Holland focused on autumn and winter, which are strongly influenced by the summertime reduction of sea ice and the subsequent timing of the ice regrowth. They found that the air temperatures over the ocean will enter a new climate during the first half or middle of this century, with air temperatures over land warming substantially later in the century.The seasonal cycle of precipitation will change dramatically by the middle of the century. If emissions persist at a high level, most continental regions will experience an increase in the rainy season of 20-60 days by mid-century and 60-90 days by the end of the century. In some Arctic regions, rain may occur any month of the year by century's end."The Arctic is likely to experience extremes in sea ice, temperature, and precipitation that are far outside anything that we've experienced before," Landrum said. "We need to change our definition of what Arctic climate is."

Pollution

September 14, 2020

https://www.sciencedaily.com/releases/2020/09/200914083844.htm

Hitchhiking seeds pose substantial risk of nonnative plant invasions

Seeds that float in the air can hitchhike in unusual places -- like the air-intake grille of a refrigerated shipping container. A team of researchers from the USDA Forest Service, Arkansas State University, and other organizations recently conducted a study that involved vacuuming seeds from air-intake grilles over two seasons at the Port of Savannah, Georgia.

The viability of such seeds is of significant interest to federal regulatory and enforcement agencies, and the project required a shared stewardship approach. Imported refrigerated shipping containers are inspected by the U.S. Customs & Border Protection, Agriculture Program (Department of Homeland Security). The research team worked closely with this agency, as well as the USDA Animal and Plant Health Inspection Service, and the Georgia Ports Authority.Their findings were recently published in the journal Federal noxious weeds pose immediate, significant threats to agriculture, nursery, and forestry industries. Although a lovely grass and useful in its native range, wild sugarcane has the potential to join cogongrass, stiltgrass, and other nonnative species that have become extremely widespread in the U.S."During the two shipping seasons, we estimate that over 40,000 seeds from this species entered the Garden City Terminal at the Port of Savannah," says Rima Lucardi, a Forest Service researcher and lead author of the project. "This quantity of incoming seeds is more than sufficient to cause introduction and establishment of this nonnative invader, even If the escape rate from the shipping containers is limited."To estimate the chance that seeds would survive and establish in the U.S., Lucardi and her colleagues analyzed and modeled viable seeds from four plant taxa. All are prolific seed producers, wind-pollinated and wind-dispersed, and able to persist in a wide range of environmental conditions and climates.The researchers propose several possible strategies for reducing risk to native ecosystems and agricultural commodities. For example, in lieu of labor-intensive vacuuming of air-intake grilles, a liquid pre-emergent herbicide could potentially be applied to containers while in port. Prevention and best management practices, from the farm to the store, reduce the probability of nonnative seeds establishing in the U.S. Inspection for exterior seeds hitching a ride on shipping containers at their points-of-origin or stops along the way would also reduce risk of invasion.Preventing nonnative plant invasions is much more cost-effective in the long run than trying to manage them once they have spread and become widely established. "Investment in the prevention and early detection of nonnative plant species with known negative impacts results in nearly a 100-fold increase in economic return when compared to managing widespread nonnatives that can no longer be contained," says Lucardi.

Pollution

September 11, 2020

https://www.sciencedaily.com/releases/2020/09/200911110809.htm

Volcanic ash may have a bigger impact on the climate than we thought

When volcanoes erupt, these geologic monsters produce tremendous clouds of ash and dust -- plumes that can blacken the sky, shut down air traffic and reach heights of roughly 25 miles above Earth's surface.

A new study led by the University of Colorado Boulder suggests that such volcanic ash may also have a larger influence on the planet's climate than scientists previously suspected.The new research, published in the journal "What we found for this eruption is that the volcanic ash can persist for a long time," said Yunqian Zhu, lead author of the new study and a research scientist at the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder.The discovery began with a chance observation: Members of the research team had been flying an unmanned aircraft near the site of the Mount Kelut eruption -- an event that covered large portions of Java in ash and drove people from their homes. In the process, the aircraft spotted something that shouldn't have been there."They saw some large particles floating around in the atmosphere a month after the eruption," Zhu said. "It looked like ash."She explained that scientists have long known that volcanic eruptions can take a toll on the planet's climate. These events blast huge amounts of sulfur-rich particles high into Earth's atmosphere where they can block sunlight from reaching the ground.Researchers haven't thought, however, that ash could play much of a role in that cooling effect. These chunks of rocky debris, scientists reasoned, are so heavy that most of them likely fall out of volcanic clouds not long after an eruption.Zhu's team wanted to find out why that wasn't the case with Kelut. Drawing on aircraft and satellite observations of the unfolding disaster, the group discovered that the volcano's plume seemed to be rife with small and lightweight particles of ash -- tiny particles that were likely capable of floating in the air for long periods of time, much like dandelion fluff."Researchers have assumed that ash is similar to volcanic glass," Zhu said. "But what we've found is that these floating ones have a density that's more like pumice."Study coauthor Brian Toon added that these pumice-like particles also seem to shift the chemistry of the entire volcanic plume.Toon, a professor in LASP and the Department of Atmospheric and Oceanic Sciences at CU Boulder, explained that erupting volcanos spew out a large amount of sulfur dioxide. Many researchers previously assumed that those molecules interact with others in the air and convert into sulfuric acid -- a series of chemical reactions that, theoretically, could take weeks to complete. Observations of real-life eruptions, however, suggest that it happens a lot faster than that."There has been a puzzle of why these reactions occur so fast," Toon said.He and his colleagues think they've discovered the answer: Those molecules of sulfur dioxide seem to stick to the particles of ash floating in the air. In the process, they may undergo chemical reactions on the surface of the ash itself -- potentially pulling around 43% more sulfur dioxide out of the air.Ash, in other words, may hasten the transformation of volcanic gases in the atmosphere.Just what the impact of those clouds of ash are on the climate isn't clear. Long-lasting particles in the atmosphere could, potentially, darken and even help to cool the planet after an eruption. Floating ash might also blow all the way from sites like Kelut to the planet's poles. There, it could kickstart chemical reactions that would damage Earth's all-important ozone layer.But the researchers say that one thing is clear: When a volcano blows, it may be time to pay a lot more attention to all that ash and its true impact on Earth's climate."I think we've discovered something important here," Toon said. "It's subtle, but it could make a big difference."

Pollution

September 10, 2020

https://www.sciencedaily.com/releases/2020/09/200910150350.htm

Multiphase buffering by ammonia explains wide range of atmospheric aerosol acidity

Aerosols are tiny solid or liquid particles suspended in the air. They influence the climate by absorbing or scattering sunlight and serving as cloud condensation nuclei. Moreover, they can impact human well-being through adverse health effects of fine particulate matter.

A large fraction of particulate matter consists of nitrate, sulfate, and ammonium ions. The formation of these major aerosol components is strongly influenced by aerosol acidity, which varies widely between different regions with aerosol pH values ranging from ~1 to ~6. The drivers of these large variations, however, are not clear.Researchers have now discovered how important the water content and total mass concentration of aerosol particles are for their acidity. A team led by Yafang Cheng and Hang Su from the Max Planck Institute for Chemistry discovered that these factors can be even more important than the dry particle composition. For populated continental areas with high anthropogenic emissions of ammonia from agriculture, traffic, and industry, they found that aerosol pH can be efficiently buffered and stabilized at different levels by the conjugate acid-base pair of ammonium ions and ammonia (NHThe investigations now published in the interdisciplinary research journal `"It turned out that the acid-base pair NH4+/NH3 is buffering the aerosol pH over most populated continental areas, even though the acidity may vary by multiple pH units," says Yafang Cheng, Minerva Research Group leader at the Max Planck Institute for Chemistry. "Variations in water content are responsible for 70-80 percent of global variability in aerosol pH in ammonia-buffered regions, which was not previously known and can be explained by our new multiphase buffer theory," she adds.In particular, the Max Planck researchers used their model to compare aerosol composition and acidity for two very different geographic regions and conditions. In the southeastern United States during summer, the air is clean, and the few atmospheric aerosol particles contain little water at pH values around ~1, whereas there are typically high aerosol concentrations with high water content at pH values around ~5 over the North China Plain in winter. "We find that these large differences in aerosol pH are primarily due to differences in aerosol loading and water content rather than differences in the nitrate content as assumed in earlier studies," explains Guangjie Zheng, a postdoc in Yafang Cheng's group."Globally, ~70% of urban areas are in the ammonia-buffered regime," summarizes Hang Su, scientific group leader in the Multiphase Chemistry Department of the institute. "Thus, the newly discovered multiphase buffer mechanism is important to understand haze formation and aerosol effects on human health and climate in the Anthropocene."The results of the team around Cheng and Su not only imply that aerosol pH and atmospheric multiphase chemistry are strongly affected by the pervasive human influence on ammonia emissions and the nitrogen cycle in the Anthropocene. They also improve the understanding how air pollution develops and thus provide an important approach for possible control measures.

Pollution

September 9, 2020

https://www.sciencedaily.com/releases/2020/09/200909114835.htm

New insight on the impacts of Earth's biosphere on air quality

A new study led by a team of University of Minnesota researchers provides the first global satellite measurements of one of the most important chemicals affecting Earth's atmosphere.

Isoprene is a natural hydrocarbon emitted to the atmosphere in vast quantities -- approximately 500 billion kg per year -- by plants and trees. Isoprene is chemically reactive, and once in the atmosphere it combines with human-caused pollutants to adversely affect air quality. Isoprene also reacts with the main atmospheric oxidizing agent -- called OH radicals -- and therefore reduces the capacity of the atmosphere to scrub itself of pollutants and greenhouse gases.Scientists look to atmospheric models to predict current and future atmospheric composition and air quality, as well as to diagnose the atmosphere's ability to remove greenhouse gases and air pollutants. But isoprene emission rates are highly uncertain due to sparse ground-based measurements, and scientists are also unsure of the extent to which isoprene acts to suppress or sustain the abundance of OH radicals in the atmosphere.Now, researchers have developed the first-ever global measurements of isoprene from space. Using observations from the Cross-track Infrared Sounder (CrIS) satellite sensor, researchers developed a retrieval method that uses machine learning to determine the atmospheric concentration of isoprene over different parts of the world. They combined these measurements with atmospheric modeling to test current scientific understanding of global isoprene emissions and how isoprene affects atmospheric oxidation. The research will be published on Wednesday, September 9 in the journal "Isoprene is one of the most important drivers of global atmospheric chemistry," said Dylan Millet, a professor in the U of M's Department of Soil, Water, and Climate. "These satellite measurements provide new understanding of how Earth's biosphere and atmosphere interact."By combining the CrIS isoprene measurements with other satellite data, for the first time researchers were able to estimate the abundance of OH from space over isoprene source regions. These observations support recent laboratory and theory-based findings: isoprene emissions do lower atmospheric OH, but not nearly as strongly as was originally believed. As a result, the atmosphere maintains a significant ability to scrub itself of pollution even in the presence of natural isoprene emissions. Combining these measurements with other space-based data will open new doors to investigate changes in OH over time.This research lays a foundation for multi-year studies examining seasonal-to-interannual isoprene changes and their impacts on the global atmosphere. Information from these new satellite measurements can also be used to improve current atmospheric models, with the goal of more accurately predicting air quality in a changing climate.Researchers revealed that:-Over southern Africa, the CrIS measurements reveal a major isoprene hotspot that is missing from bottom-up predictions. This points to a need for further investigation of isoprene sources in this understudied region."These new satellite measurements reveal that, while our understanding of isoprene chemistry is getting pretty good, we still have a lot to learn about how isoprene emissions vary across Earth's different ecosystems," said Kelley Wells, a researcher in the Department of Soil, Water, and Climate in the U of M's College of Food, Agricultural and Natural Resource Sciences.

Pollution

September 8, 2020

https://www.sciencedaily.com/releases/2020/09/200908122522.htm

Lockdown did not reduce 'most harmful' type of air pollution in Scotland

The significant reduction in vehicle journeys during the COVID-19 lockdown did not reduce the level of toxic fine particles in Scotland's air, according to experts at the University of Stirling.

Analysis of fine particulate air pollution (PM2.5) in the first month of restrictions found little change -- despite a 65 per cent reduction in the number of vehicles on the country's roads.The team that led the research, from Stirling's Institute for Social Marketing and Health, say their findings suggest that traffic is not a key contributor to outdoor air pollution in Scotland -- and, in fact, that people may be at greater risk from air pollution in their own homes.Dr Ruaraidh Dobson, who led the study, said: "It has been assumed that fewer cars on the road might have led to a decline in the level of air pollution outdoors and, in turn, reduce the number of cases of ill health linked to this pollution. However, our study -- contrary to research from places such as Wuhan in China, and Milan -- found no evidence of fine particulate air pollution declining in Scotland because of lockdown."This suggests that vehicles aren't an important cause of this very harmful type of air pollution in Scotland -- and people may be at greater risk from poor air quality in their own homes, especially where cooking and smoking is taking place in enclosed and poorly ventilated spaces."Road traffic significantly reduced across the world following the introduction of COVID-19 restrictions and research has linked the change to improvements in outdoor air quality in some areas. It has been suggested that this may result in positive health effects.Dr Dobson and colleague Dr Sean Semple analysed data from 70 roadside monitoring stations around Scotland from March 24 -- the day after lockdown was introduced in the UK -- to April 23. They then compared the data to comparative 31-day periods in 2017, 2018 and 2019.They found that, across Scotland, the geometric mean concentration of PM2.5 was 6.6 micrograms per cubic metre of air (?g/m3) in the observed period in 2020 -- similar to the levels in 2017 (6.7 ?g/m3) and 2018 (7.4 ?g/m3).The 2020 figure was substantially lower than the markedly high concentrations observed in 2019 (12.8 ?g/m3), however, the authors pointed out this was an "outlier" likely caused by a meteorological event that caused fine particulate dust from the Saharan desert to impact on UK air quality in April of that year. Significantly, removing the affected period from the 2019 analysis, reduces the mean value to (7.8 ?g/m3).The team did, however, note a reduction in nitrogen dioxide -- specifically associated with vehicle exhaust emissions -- in 2020, compared to the other three years.Explaining that personal exposure to potentially harmful air could have actually increased during the lockdown, due to people spending more time at home, the paper says: "Lockdowns are intended to result in people spending more time in their homes. This could increase population exposure to indoor air pollution, such as cooking fumes and second-hand tobacco smoke."It continues: "In countries, like Scotland, where it appears that the lockdown has not led to reductions in outdoor fine particulate matter pollution, it is possible that personal exposure to PM2.5 may actually have increased rather than declined, due to higher concentrations from indoor sources of particulate within the home setting."This could increase adverse health effects overall and also health inequalities -- lower income people are more likely to smoke and to smoke indoors, and are likely to have smaller homes leading to higher PM2.5 concentrations from individual sources, due to smaller room volumes."If the severity of COVID-19 is related to air pollution exposure -- as has been suggested -- increased exposure to PM2.5 could potentially increase the death toll of that disease. Careful and balanced consideration of both outdoor and indoor sources of PM2.5 is essential to tackling the health harm of air pollution effectively and equitably."

Pollution

September 2, 2020

https://www.sciencedaily.com/releases/2020/09/200902152154.htm

Asphalt adds to air pollution, especially on hot, sunny days

Asphalt is a near-ubiquitous substance -- it's found in roads, on roofs and in driveways -- but its chemical emissions rarely figure into urban air quality management plans.

A new study finds that asphalt is a significant source of air pollutants in urban areas, especially on hot and sunny days.Yale researchers observed that common road and roofing asphalts produced complex mixtures of organic compounds, including hazardous pollutants, in a range of typical temperature and solar conditions. The results of their work, from the lab of Drew Gentner, associate professor of chemical & environmental engineering, appear Sept. 2 in the journal Decades of research about and regulations of emissions from motor vehicles and other combustion-related sources have resulted in improved urban air quality. But recent studies show that as those efforts succeeded, numerous non-combustion-related sources have become important contributors of organic compounds. These can lead to secondary organic aerosol (SOA), a major contributor of PM2.5 -- an important regulated air pollutant comprising particles smaller than 2.5 micrometers in diameter -- that have significant effects on public health.The researchers collected fresh asphalt and heated it to different temperatures. "A main finding is that asphalt-related products emit substantial and diverse mixtures of organic compounds into the air, with a strong dependence on temperature and other environmental conditions," said Peeyush Khare, a graduate student in Gentner's lab and lead author of the study.After some time, the emissions at summer temperatures leveled out, but they persisted at a steady rate -- suggesting there are long-term, continued emissions from asphalt in real-world conditions. "To explain these observations, we calculated the expected rate of steady emissions and it showed that the rate of continued emissions was determined by the time it takes for compounds to diffuse through the highly viscous asphalt mixture," Gentner said.They also examined what happens when asphalt is exposed to moderate solar radiation and saw a significant jump in emissions -- up to 300% for road asphalt -- demonstrating that solar radiation, and not only temperature, can increase emissions."That's important from the perspective of air quality, especially in hot, sunny summertime conditions," Khare said.Paved surfaces and roofs make up approximately 45% and 20% of surfaces in U.S. cities, respectively. The researchers estimated the potential total emissions and formation of SOA in Los Angeles, a key city for urban air quality case studies.Because of the types of compounds asphalt emits, its potential SOA formation is comparable to motor vehicle emissions in Los Angeles, the researchers said -- implying that finding ways to make roads more environmentally friendly is as important as doing the same for cars and trucks. Gentner noted, though, that the effect of asphalt emissions on ozone formation was minimal compared to that of motor vehicles and volatile chemicals in personal care and cleaning products -- another key emerging source of reactive organic emissions that produces large quantities of SOA in urban areas.Gentner emphasized that asphalt is just one piece in the puzzle of urban SOA."It's another important non-combustion source of emissions that contributes to SOA production, among a class of sources that scientists in the field are actively working to constrain better," he said.

Pollution

September 2, 2020

https://www.sciencedaily.com/releases/2020/09/200902091112.htm

Common sunscreen ingredients prove dangerous for freshwater ecosystems

The active ingredients found in sunscreen have detrimental effects on freshwater ecosystems, according to new research by University of Alberta biologists.

The results show that long-term exposure to ultraviolet (UV) filters -- including avobenzone, oxybenzone, and octocrylene -- is lethal for some organisms living in freshwater environments. One of the largest sources of UV-filter contamination in both marine and freshwater environments is from sunscreen leaching off of the skin while swimming."We do know that UV-filters are particularly devastating to coral reefs and cause bleaching, but there has been almost no research on what the effects are to freshwater animals," explained Aaron Boyd, graduate student in the Department of Biological Sciences and lead author on the paper. "To address this, we examined the effects of UV-filters in the water flea, The results show that exposure to UV-filters over a 48-hour period prevented the fleas from navigating through their environment. Exposure over a 14-day period -- similar to what might occur near popular beach areas -- proved lethal for the tiny crustaceans."This is particularly bad for a freshwater ecosystem as a whole, as Daphnia are an important part of the food chain for many smaller species of fish," added Boyd, who completed this research in collaboration with graduate student Connor Stewart, under the supervision of Assistant Professor Tamzin Blewett and Professor Keith Tierney. "Losing a Daphnia population would put all of the species that rely on them at risk of starvation, and in certain conditions could cause the local ecosystem to collapse."The good news, Boyd explained, is that the fleas were able to recover their ability to navigate through the water once the contamination was removed -- a good sign for environmental recovery. "These chemicals are short-lived in the environment, so if we remove the sources of pollution, then there is a reasonable chance for the organisms in those environments to recover," he said.Further research is required to better understand the long-term impact of UV-filters -- and research continues in the search for non-toxic UV filters.

Pollution

September 2, 2020

https://www.sciencedaily.com/releases/2020/09/200902082343.htm

The widespread footprint of blue jean microfibers

With many people working from home during the COVID-19 pandemic, blue jeans are a more popular wardrobe choice than ever. But most people don't think about microscopic remnants of their comfy jeans and other clothing that are shed during laundering. Now, researchers reporting in ACS'

Over the past 100 years, the popularity of denim blue jeans has grown immensely, with many people wearing this type of clothing almost every day. Studies have shown that washing denim and other fabrics releases microfibers -- tiny, elongated particles -- to wastewater. Although most microfibers are removed by wastewater treatment plants, some could still enter the environment through wastewater discharge, also known as effluent. Blue jean denim is composed of natural cotton cellulose fibers, processed with synthetic indigo dye and other chemical additives to improve performance and durability. Miriam Diamond, Samantha Athey and colleagues wondered whether blue jeans were a major source of anthropogenic cellulose microfibers to the aquatic environment.The researchers used a combination of microscopy and Raman spectroscopy to identify and count indigo denim microfibers in various water samples collected in Canada. Indigo denim made up 23, 12 and 20% of all microfibers in sediments from the Great Lakes, shallow suburban lakes near Toronto, Canada, and the Canadian Arctic Archipelago, respectively. Despite a high abundance of denim microfibers in Great Lake sediments, the team detected only a single denim microfiber in the digestive tract of a type of fish called rainbow smelt. Based on the levels of microfibers found in wastewater effluent, the researchers estimated that the wastewater treatment plants in the study discharged about 1 billion indigo denim microfibers per day. In laundering experiments, the researchers found that a single pair of used jeans could release about 50,000 microfibers per wash cycle. Although the team doesn't know the effects, if any, that the microfibers have on aquatic life, a practical way to reduce denim microfiber pollution would be for consumers to wash their jeans less frequently, they say. Moreover, finding microfibers from blue jeans in the Arctic is a potent indicator of humans' impact on the environment, the researchers add.

Pollution

September 1, 2020

https://www.sciencedaily.com/releases/2020/09/200901112208.htm

How dangerous are burning electric cars?

There' s a loud bang, and then it starts: A battery module of an electric car is on fire in the Hagerbach test tunnel. A video of the test impressively shows the energy stored in such batteries: Meter-long flames hiss through the room and produce enormous amounts of thick, black soot. The visibility in the previously brightly lit tunnel section quickly approaches zero. After a few minutes, the battery module is completely burnt out. Ash and soot have spread throughout the room.

The trial, which was funded by the Swiss Federal Roads Office (FEDRO) and in which several Empa researchers participated, took place in December 2019. The results have just been published. "In our experiment we were considering in particular private and public operators of small and large underground or multi-story car parks," says project leader Lars Derek Mellert of Amstein + Walthert Progress AG. "All these existing underground structures are being used to an increasing extent by electric cars. And the operators ask themselves: What to do if such a car catches fire? What are the health risks for my employees? What effects does such a fire have on the operation of my plant?" But until now there has been hardly any meaningful technical literature, let alone practical experience for such a case.With the support of battery researcher Marcel Held and corrosion specialist Martin Tuchschmid from Empa, Mellert developed three test scenarios. Experts from the Hagerbach AG test tunnel and the French Centre d'études des tunnels (CETU) in Bron were also involved. "We installed test surfaces in the fire tunnel on which the soot settled," explains Martin Tuchschmid, corrosion and fire damage specialist at Empa. "After the test, the surfaces were chemically analyzed and also stored in special rooms for several months to detect possible corrosion damage."The first scenario involves a fire in a closed car park without mechanical ventilation. A parking space of 28 x 28 meters area and 2.5 meters floor height was assumed. Such a floor would have an air volume of 2000 cubic meters. The fire of a small car with a fully charged battery of 32 kWh is assumed. For reasons of test economy everything was scaled down to 1/8. Thus, a fully charged battery module with 4 kWh capacity was set on fire in a room with 250 cubic meters of air volume. The tests investigated how the soot settles on tunnel walls, surfaces and on protective suits worn by firefighters on site, how toxic the residues are and by what means the fire site can be cleaned after the event.Scenario 2 deals with chemical residues in the extinguishing water. The test set-up was the same as in scenario 1. But this time, the smoke from the battery was channeled with the aid of a metal plate beneath a water shower that resembled a sprinkler system. The sooty water that rained down was collected in a basin. The battery was not extinguished, but burned out completely.In this scenario, the focus of the study lay on the effect of such a fire on a ventilation system. How far is the soot distributed in the exhaust ducts? Do substances that would cause corrosion settle there? In the experiment, a 4 kWh battery module was again set on fire, but this time a fan blew the smoke at a constant speed into a 160-meter-long ventilation tunnel. At a distance of 50, 100 and 150 meters from the site of the fire, the researchers had installed metal sheets in the tunnel where the soot would settle. The chemical composition of the soot and possible corrosion effects were analyzed in the Empa laboratories.The results of the test were published in a final report in August 2020. Project leader Mellert reassures: In terms of heat development a burning electric car is not more hazardous than a burning car with a conventional drive. "The pollutants emitted by a burning vehicle have always been dangerous and possibly fatal," says the final report. Regardless of the type of drive or energy storage system, the primary objective has to be to get everyone out of the danger zone as quickly as possible. The highly corrosive, toxic hydrofluoric acid has often been discussed as a particular danger in burning batteries. In the three tests in the Hagerbach tunnel, however, the concentrations remained below critical levels.Conclusion: A tunnel ventilation system that is state-of-the-art can cope not only with burning gasoline/diesel cars, but also with electric cars. Increased corrosion damage to the ventilation system or the tunnel equipment is also unlikely based on the results now available.Even the fire brigades do not have to learn anything new on the basis of the tests. Firefighters know that the battery of an electric car is impossible to extinguish and that it can only be cooled with large amounts of water. So the fire can possibly be limited to a few battery cells, and part of the battery will not burn out. Of course, such a partially burnt wreck must be stored in a water basin or a special container so that it cannot reignite. But this is already known to the specialists and is being practiced.A problem, however, is the extinguishing and cooling water that is produced when fighting such a fire and storing a burnt-out battery in a water basin. The analyses showed that the chemical contamination of the extinguishing water exceeds the Swiss threshold values for industrial wastewater by a factor of 70; the cooling water is even up to 100-times above threshold values. It is important that this highly contaminated water does not enter the sewage system without proper treatment.After the trials, the tunnel was decontaminated by a professional fire clean-up team. Samples taken subsequently confirmed that the methods and time required were sufficient for the clean-up after an electric car fire. But Mellert warns especially private owners of underground garages: "Do not try to clean up the soot and dirt yourself. The soot contains large amounts of cobalt oxide, nickel oxide and manganese oxide. These heavy metals cause severe allergic reactions on unprotected skin." So clean-up after an electric car fire is definitely a job for professionals in protective suits.

Pollution

August 31, 2020

https://www.sciencedaily.com/releases/2020/08/200831165710.htm

How weather news impacts public transit ridership

If the words in a weather forecast, such as "cool," "sunny" or "windy," can influence the way you dress for the day -- can they also influence whether or not you take public transit?

In new research published in "This is encouraging," Benney says. "There's a lot of potential in terms of reaching a lot of different actors that could have a big influence or encourage ridership."Mendoza, a research assistant professor in the Department of Atmospheric Sciences and visiting assistant professor in the Department of City & Metropolitan Planning, previously studied how transit ridership along the Wasatch Front, on the buses and trains of the Utah Transit Authority (UTA), impacted air quality. The impact is greater when more people are riding since low-ridership trips, particularly on older buses, can actually have a net contribution to air pollution.Around the same time Tabitha Benney, an associate professor in the Department of Political Science, was looking at surveys of Utahns that included their reasons for using transit or not. "We were surprised at some of the responses," she says, "and that led me to pursue asking questions about what matters in terms of what could be in the media or how it could be influencing people."So Mendoza and Benney, along with co-authors Martin Buchert and John Lin, looked at how media coverage of the weather and air quality correlated with transit ridership. For the years 2014-2016, they scanned 40 local Utah media outlets for words related to weather (such as "cloudy," "freezing," or "summer"), air quality (red, yellow or green air day, according to the state's color-coded air quality system) and air pollution (such as "ozone," "PM2.5" or "particulate matter"). Then they looked at the transit ridership the day after the media coverage and noted the actual air quality of that day."We wanted to ask if there are any additional factors that would encourage or discourage ridership," Mendoza says.UTA has three main modes of transportation: buses, light rail (TRAX) and commuter rail (FrontRunner). FrontRunner riders tend to ride for farther distances, and their rider behavior, the authors found, didn't vary much with media terms. The most variation, they found, was in bus ridership.Within that variation, a few media terms related to weather stood out. On average, more usage of the term "good weather" was correlated with more ridership the following day. Similarly, more usage of "winter" was associated with increased ridership, but that may be related to the seasonal nature of U students, the authors say, as the U is the single largest paid pass purchaser from UTA.Few UTA bus stops have a weather shelter, Mendoza says (although UTA has added more shelters in recent years). Media reports of bad weather, he suggests, could discourage bus ridership.When looking at color-coded air quality terms, the researchers found less ridership on the bus system on days following use of "orange air day" and "red air day." That could be due to non-commuter bus users who ride the bus for discretionary transportation choosing to stay home to avoid poor air quality and the cold temperatures that typically accompany poor air quality days."Ridership is associated with favorable weather conditions and air quality," the authors wrote, "suggesting that ridership volume may be influenced by an overall sense of comfort and safety."They also found that less technical terms, such as "particulate matter" instead of "PM2.5," were correlated with greater changes in ridership. Same with the color-coded "red air day" term."That kind of surprised us," Benney says. Another surprise was the finding that reports of bad air quality reduced ridership, and that reports of good air quality didn't boost it."You would expect a strong relationship to clean air with people wanting to move in that direction," she says. "And that's obviously significant."Benney says that the study focused on web-accessible media outlets and did not take into account social media, which could have a significant influence on younger audiences, who tend to ride buses more. Upcoming work, she says, will look closer at the sources of Utahns' information about weather and air quality, including from religious services.The study is encouraging, she adds, because it suggests that messages may be able to influence day-to-day rider behavior. "This opens up a lot of opportunities for large institutional actors to help promote better air quality through ridership," she says.And the impact has already begun. The Utah Legislature passed a bill in 2019 that launched a three-year pilot program to provide free fares on UTA transit on poor air quality days. Preliminary findings from this research, Mendoza says, provided part of the bill's supporting scientific basis.Additionally, he says, some of the largest employers in the Salt Lake Valley, including the University of Utah, may be able to use these findings to effectively encourage employees to make air-friendly choices through riding transit or choosing to telework. "And now we're all getting really used to telework!" he says. "Because of that we can actually start to potentially move the needle by reducing the vehicular traffic."

Pollution

August 31, 2020

https://www.sciencedaily.com/releases/2020/08/200831112343.htm

Humans' construction 'footprint' on ocean quantified for first time

In a world-first, the extent of human development in oceans has been mapped. An area totalling approximately 30,000 square kilometres -- the equivalent of 0.008 percent of the ocean -- has been modified by human construction, a study led by Dr Ana Bugnot from the University of Sydney School of Life and Environmental Sciences and the Sydney Institute of Marine Science has found.

The extent of ocean modified by human construction is, proportion-wise, comparable to the extent of urbanised land, and greater than the global area of some natural marine habitats, such as mangrove forests and seagrass beds.When calculated as the area modified inclusive of flow-on effects to surrounding areas, for example, due to changes in water flow and pollution, the footprint is actually two million square kilometres, or over 0.5 percent of the ocean.The oceanic modification includes areas affected by tunnels and bridges; infrastructure for energy extraction (for example, oil and gas rigs, wind farms); shipping (ports and marinas); aquaculture infrastructure; and artificial reefs.Dr Bugnot said that ocean development is nothing new, yet, in recent times, it has rapidly changed. "It has been ongoing since before 2000 BC," she said. "Then, it supported maritime traffic through the construction of commercial ports and protected low-lying coasts with the creation of structures similar to breakwaters."Since the mid-20th century, however, ocean development has ramped up, and produced both positive and negative results."For example, while artificial reefs have been used as 'sacrificial habitat' to drive tourism and deter fishing, this infrastructure can also impact sensitive natural habitats like seagrasses, mudflats and saltmarshes, consequently affecting water quality."Marine development mostly occurs in coastal areas -- the most biodiverse and biologically productive ocean environments."Future expansion 'alarming'Dr Bugnot, joined by co-researchers from multiple local and international universities, also projected the rate of future ocean footprint expansion."The numbers are alarming," Dr Bugnot said. "For example, infrastructure for power and aquaculture, including cables and tunnels, is projected to increase by 50 to 70 percent by 2028."Yet this is an underestimate: there is a dearth of information on ocean development, due to poor regulation of this in many parts of the world."There is an urgent need for improved management of marine environments. We hope our study spurs national and international initiatives, such as the EU Marine Strategy Framework Directive, to greater action."The researchers attributed the projected expansion on people's increasing need for defences against coastal erosion and inundation due to sea level rise and climate change, as well as their transportation, energy extraction, and recreation needs.

Pollution

August 25, 2020

https://www.sciencedaily.com/releases/2020/08/200825124624.htm

Researchers introduce new theory to calculate emissions liability

A comparison of the results for conventional point source pollution and bottleneck carbon emissions sources shows that oil and natural gas pipelines are far more important than simple point-source emissions calculations would indicate. It also shifts the emissions liability towards the East Coast from the Midwest. Most surprisingly, the study found that seven out of eight oil pipelines in the U.S. responsible for facilitating the largest amount of carbon emissions are not American.

Fossil fuels (coal, oil and natural gas) emit carbon dioxide when burned, which scientists say is the greenhouse gas primarily responsible for global warming and climate change. Climate change causes numerous problems that economists call "externalities," because they are external to the market. In a new study published in Pearce explained their past work found that "as climate science moves closer to being able to identify which emitters are responsible for climate costs and disasters, emissions liability is becoming a profound business risk for some companies."Most work in carbon emissions liability focuses on who did the wrong and what the costs are. Pascaris and Pearce's "bottleneck" theory places the focus on who enables emissions.The U.S. Environmental Protection Agency defines point source pollution as "any single identifiable source of pollution from which pollutants are discharged." For example, pipelines themselves create very little point source pollution, yet an enormous amount of effort has been focused on stopping the Keystone XL Pipeline because of the presumed emissions it enables.The Michigan Tech study asked: Would the magnitude of the emissions enabled by a pipeline warrant the effort, or should lawsuits be focused elsewhere if minimizing climate change is the goal?In order to answer this question quantitatively, the study presented an open and transparent methodology for prioritizing climate lawsuits based on an individual facility's ability to act as a bottleneck for carbon emissions."Just like a bottleneck that limits the flow of water, what our emissions bottleneck theory does is identify what carbon emissions would be cut off if a facility was eliminated rather than only provide what emissions come directly from it as a point source," Pearce said. "This study found that point source pollution in the context of carbon emissions can be quite misleading."The results showed that the prominent carbon emission bottlenecks in the U.S. are for transportation of oil and natural gas. While the extraction of oil is geographically concentrated in both North Dakota and Texas, the pipeline network is extensive and transcends both interstate and national boundaries, further complicating legal issues.Overall, seven of eight oil pipelines in the U.S. are foreign owned and accountable for contributing 74% of the entire oil industry's carbon emissions. They are a likely prioritization for climate-related lawsuits and thus warrant higher climate liability insurance premiums.As a whole, fossil-fuel related companies identified in the study have increased risks due to legal liability, future regulations meant to curb climate destabilization and as targets for eco-terrorism."All of these business risks would tend to increase insurance costs, but significant future work is needed to quantify what climate liability insurance costs should be for companies that enable major carbon emissions," concluded Pearce.

Pollution

August 25, 2020

https://www.sciencedaily.com/releases/2020/08/200824105905.htm

Affordable and scalable nitrogen dioxide sensor

Scientists at the University of Sussex have collaborated with an Oxford company, M-SOLV, and a team of scientists from across Europe to develop a highly sensitive and accurate Nitrogen Dioxide (NO

The gas sensor could, for the first time, provide accurate readings of the NOEuropean Union regulations allow a threshold of 20 parts-per-billion (ppb) of NOThe challenge the scientists faced, therefore, was to create a device that was sensitive and accurate enough to detect below 20 parts-per-billion of NOTheir breakthrough came when they developed an NOUsing a scalable and cheap one-step-laser process, the thin, porous and well-adhered film of LDCA is then deposited on to electrodes, which can then be housed in a range of device structures for continuous air monitoring. The sensor is so sensitive that it can detect close to 10 parts-per-billion of NOProfessor Alan Dalton, who heads up the Materials Physics group at the University of Sussex says: "Like condensation on a windowpane, nanomaterials such as the carbon that we have used in this development, nearly always have surface water. Normally this is a really bad thing as it interferes with the technology, but in this case, we've been able to use this layer of water to our advantage to selectively dissolve NO"As a physicist this is really exciting as this is what gives our sensor such a high rate of sensitivity to NOPotential applications for the sensor could include: as a safety device to monitor the air quality in a baby's bedroom; to help inform the best walking or cycling routes and times of day to avoid high pollution levels; and even by estate agents to provide prospective house buyers with information on the Nitrogen Dioxide levels in a home and area. The scientists hope that the technology will be utilised by councils to track pollution levels in urban environments and industry.Peter Lynch, a postdoctoral researcher at the University of Sussex who played a key role on the sensor development, says: "As a team of scientists from across Europe, one of our shared goals was to develop a sensor that would not only perform fantastically outside of the lab, but that would also be affordable enough to be available to your average household, ensuring that more of us have access to information on air quality in our local area and on an hour-by-hour basis."As well as helping individuals make informed choices, our hope is that this data could also feed into a national -- even world-wide -- pollution monitoring database, in order to effect positive action on air quality."Adam Brunton, Director of Business Development at M-SOLV, who are manufacturing the NO

Pollution

August 24, 2020

https://www.sciencedaily.com/releases/2020/08/200824165632.htm

Advanced biofuels show real promise for replacing some fossil fuels

Biofuel and bioenergy systems are integral to scenarios for displacing fossil fuel use and producing negative emissions through carbon capture and storage. But the net greenhouse gas mitigation benefit of these systems has been controversial, due to concerns around carbon losses from changes in land use and foregone sequestration benefits from alternative land uses.

A new study led by Colorado State University -- including an interdisciplinary team of plant scientists, ecologists and engineers -- predicted significant climate benefits stemming from the use of advanced biofuel technologies. Accounting for all of the carbon flows in biofuel systems and comparing them to those in grasslands and forests, the team found that there are clear strategies for biofuels to have a net carbon benefit.This is one of the first studies to look at both current and future carbon-negative biofuels."Robust paths to net greenhouse gas mitigation and negative emissions via advanced biofuels," was published August 24 in John Field, research scientist at the Natural Resource Ecology Lab at CSU, said that it has been a challenge for the biofuel industry to demonstrate commercial viability for cellulosic biofuels, created using nonedible parts of plants. Switchgrass, a native grass that grows in many parts of North America, is a leading candidate for the sustainable production of plant material.The research team used modeling to simulate switchgrass cultivation, cellulosic biofuel production and carbon capture and storage, tracking ecosystem and carbon flows. Scientists then compared this modeling to alternative ways to store carbon on the land, including growing forest or grassland.Carbon capture and storage technology is being used by at least one facility in Illinois that is processing corn as a conventional biofuel to create ethanol, but these systems are not yet widespread. As part of the study, researchers created models to simulate what this would look like at a cellulosic biofuel refinery."What we found is that around half of the carbon in the switchgrass that comes into the refinery becomes a byproduct that would be available for carbon capture and storage," said Field. The resulting byproduct streams of high-purity carbon dioxide would not require much separation or clean-up before being stored underground.The research team analyzed three contrasting U.S. case studies and found that on land where farmers or land managers were transitioning out of growing crops or maintaining pastures for grazing, cultivating switchgrass for cellulosic ethanol production had a per-hectare mitigation potential comparable to reforestation and several-fold greater than grassland restoration. (A hectare is about two-and-a-half times the size of an average football field.)Using switchgrass can be particularly helpful in parts of the country where planting more trees is not an option."In the Great Plains, prairie is the more natural cover," said Field. "Those systems don't suck up as much carbon as a forest system does. If you start putting biofuels in the mix, they have two-and-a-half times the carbon benefits over grasslands. If you're in an area where grassland would be the native cover, there's a clear advantage to using biofuels."Field said that the team's motivation for the study comes on the heels of several prominent critiques of biofuels. "We wanted to see if we came to the same conclusion or not as the researchers who have been critical of biofuels," he said."Our analysis shows that large climate benefits can, in fact, be achieved through biofuels if there is an intent to do so," said Lee Lynd, a co-author and Paul E. and Joan H. Queneau Distinguished Professor in Environmental Engineering Design at Dartmouth College.Scientists said because of the current delays in tackling climate change, it's imperative to take a more proactive stance on biofuels and other negative emissions technologies if countries like the U.S. want to limit the impacts of global warming to 1.5 degrees Celsius above pre-industrial levels."If we want to hit that goal, we really have to deploy alternatives to fossil fuel use as quickly as we can," said Field. There is also a need to clean up carbon pollution from the atmosphere and walk back historic emissions, he added.Cleaning up carbon pollution is an idea that has been widely discussed since the Paris Agreement was established within the United Nations Framework Convention on Climate Change in 2016."We're going to have to start cleaning up some of the carbon pollution that has been emitted in the past, because we are too slow at reducing our emissions," said Field.There are different ways to accomplish this clean-up, with the simplest idea to grow trees to store more carbon on the land.Other alternatives are outlined and analyzed in the study, including the use of carbon-negative biofuels. Plants pull carbon out of the atmosphere to grow and the carbon is used to build plant tissues.If that plant material is harvested and converted to energy, some of the resulting carbon dioxide byproduct can be captured and pumped underground into storage in depleted oil wells or other geological formations, instead of sending it back into the atmosphere.Likewise, cellulosic biofuels are attractive because they could help reduce fossil fuel use in aviation, shipping and trucking, all fields that are challenging to move to electricity.Moving forward, the research team hopes to expand on its modeling, scaling it up nationally rather than looking at a few specific sites across the country."A lot of the pieces for future use of advanced biofuels exists at some small scale," said Field. "The trick is putting all of these pieces together and making sure we continue to have support so it can thrive and take off, even when gas prices are relatively low, like now."This research was funded in part by the National Institute of Food and Agriculture -- U.S. Department of Agriculture, the U.S. Department of Energy via the Center for Bioenergy Innovation, and the São Paulo Research Foundation in Brazil.

Pollution

August 24, 2020

https://www.sciencedaily.com/releases/2020/08/200824120035.htm

Negative emissions technologies may not solve climate crisis

A team led by researchers at the University of Virginia cautions that when it comes to climate change, the world is making a bet it might not be able to cover.

The team's new paper in The handful of models the United Nations Intergovernmental Panel on Climate Change and decisions makers around the world trust to develop strategies to meet carbon neutrality commitments all assume negative emissions technologies will be available as part of the solution.Negative emissions technologies, often called NETs, remove carbon dioxide from the atmosphere. The three most widely studied approaches are bioenergy with carbon capture and storage, which entails growing crops for fuel, then collecting and burying the CO"The trouble is, nobody has tried these technologies at the demonstration scale, much less at the massive levels necessary to offset current CO"Our paper quantifies their costs so we can have an honest conversation about it before we start doing this on a large scale," Clarens said.Since the Paris Agreement to limit global warming to 1.5 degrees Celsius, hammered out by world leaders in 2015, a growing number of corporations such as BP and many institutions and governments -- including UVA and Virginia -- have committed to reaching zero carbon emissions in the next few decades. Microsoft has pledged to erase its carbon emissions since its founding in 1975.To Clarens, an engineer who studies carbon management, and his fellow researchers, these are encouraging developments. Led by Clarens' Ph.D. student Jay Fuhrman, the group also includes economist Haewon McJeon and computational scientist Pralit Patel of the Joint Global Change Research Institute at the University of Maryland; UVA Joe D. and Helen J. Kington Professor of Environmental Sciences Scott C. Doney; and William M. Shobe, research director at the Weldon Cooper Center for Public Service and professor at UVA's Batten School of Leadership and Public Policy.For the research, the team used an integrated model -- one of those the United Nations relies on -- called the Global Change Assessment Model. The model was developed at the University of Maryland, which partners with the Pacific Northwest National Laboratory to run the Joint Global Change Research Institute. They compared the effects of the three negative emissions technologies on global food supply, water use and energy demand. The work looked at the role having direct air capture available would have on future climate scenarios.Biofuels and reforestation take up vast land and water resources needed for agriculture and natural areas; biofuels also contribute to pollution from fertilization. Direct air capture uses less water than planting biofuels and trees, but it still demands a lot of water and even more energy -- largely supplied by fossil fuels, offsetting some of the benefits of carbon dioxide removal. Until recently, direct air technologies also were considered too expensive to include in emissions reduction plans.The team's analysis shows that direct air capture could begin removing up to three billion tons of carbon dioxide from the atmosphere per year by 2035 -- more than 50% of U.S. emissions in 2017, the most recent year for which reliable data was available. But even if government subsidies make rapid and widespread adoption of direct air capture feasible, we'll need biofuels and reforestation to meet CO"Direct air capture can soften -- but not eliminate -- the sharpest tradeoffs resulting from land competition between farmland and land needed for new forests and bioenergy," Fuhrman and Clarens wrote in a blog accompanying the release of the paper.The costs that remain increase with time, making determined, multipronged actions toward reducing carbon dioxide emissions and removing it from the atmosphere all the more urgent, the researchers argue."We need to move away from fossil fuels even more aggressively than many institutions are considering," Clarens said. "Negative emissions technologies are the backstop the UN and many countries expect will one day save us, but they will have side effects we have to be prepared for. It's a huge gamble to sit on our hands for the next decade and say, we've got this because we're going to deploy this technology in 2030, but then it turns out there are water shortages, and we can't do it.""Before we bet the house, let's understand what the consequences are going to be," Fuhrman added. "This research can help us sidestep some of the pitfalls that could arise from these initiatives."

Pollution

August 20, 2020

https://www.sciencedaily.com/releases/2020/08/200820122040.htm

Research shows air pollution could play role in development of cardiometabolic diseases

Air pollution is the world's leading environmental risk factor, and causes more than nine million deaths per year. New research published in the Journal of Clinical Investigation shows air pollution may play a role in the development of cardiometabolic diseases, such as diabetes. Importantly, the effects were reversible with cessation of exposure.

Researchers found that air pollution was a "risk factor for a risk factor" that contributed to the common soil of other fatal problems like heart attack and stroke. Similar to how an unhealthy diet and lack of exercise can lead to disease, exposure to air pollution could be added to this risk factor list as well."In this study, we created an environment that mimicked a polluted day in New Delhi or Beijing," said Sanjay Rajagopalan, MD, first author on the study, Chief of Cardiovascular Medicine at University Hospitals Harrington Heart and Vascular Institute, and Director of the Case Western Reserve University Cardiovascular Research Institute. "We concentrated fine particles of air pollution, called PMThese particles have been strongly connected to risk factors for disease. For example, cardiovascular effects of air pollution can lead to heart attack and stroke. The research team has shown exposure to air pollution can increase the likelihood of the same risk factors that lead to heart disease, such as insulin resistance and type 2 diabetes.In the mouse model study, three groups were observed: a control group receiving clean filtered air, a group exposed to polluted air for 24 weeks, and a group fed a high-fat diet. Interestingly, the researchers found that being exposed to air pollution was comparable to eating a high-fat diet. Both the air pollution and high-fat diet groups showed insulin resistance and abnormal metabolism -- just like one would see in a pre-diabetic state.These changes were associated with changes in the epigenome, a layer of control that can masterfully turn on and turn off thousands of genes, representing a critical buffer in response to environmental factors. This study is the first-of-its-kind to compare genome-wide epigenetic changes in response to air pollution, compare and contrast these changes with that of eating an unhealthy diet, and examine the impact of air pollution cessation on these changes."The good news is that these effects were reversible, at least in our experiments" added Dr. Rajagopalan. "Once the air pollution was removed from the environment, the mice appeared healthier and the pre-diabetic state seemed to reverse."Dr. Rajagopalan explains that if you live in a densely polluted environment, taking actions such as wearing an N95 mask, using portable indoor air cleaners, utilizing air conditioning, closing car windows while commuting, and changing car air filters frequently could all be helpful in staying healthy and limiting air pollution exposure.Next steps in this research involve meeting with a panel of experts, as well as the National Institutes of Health, to discuss conducting clinical trials that compare heart health and the level of air pollution in the environment. For example, if someone has a heart attack, should they be wearing an N95 mask or using a portable air filter at home during recovery?Dr. Rajagopalan and his team believe that it is important to address the environment as a population health risk factor and continue to diligently research these issues. The authors also note that these findings should encourage policymakers to enact measures aimed at reducing air pollution.

Pollution

August 20, 2020

https://www.sciencedaily.com/releases/2020/08/200820110914.htm

February lockdown in China caused a drop in some types of air pollution, but not others

Atmospheric scientists have analyzed how the February near-total shutdown of mobility affected the air over China. Results show a striking drop in nitrogen oxides, a gas that comes mainly from tailpipes and is one component of smog.

Learning how behavior shifts due to the COVID-19 pandemic affect air quality is of immediate importance, since the virus attacks human lungs. The event is also a way for Earth scientists to study how the atmosphere responds to sudden changes in emissions."During the February 2020 shutdowns in China there was a large and rapid decline in nitrogen dioxide -- an air pollutant largely associated with transportation -- that is unprecedented in the satellite record," said Michael Diamond, a University of Washington doctoral student in atmospheric sciences."On the other hand, our analysis shows no dramatic changes in the total amount of aerosol particles in the atmosphere, or in cloud properties. This suggests the immediate climate-related impacts from the shutdown are negligible," Diamond said.He is lead author of the study published Aug. 19 in While other studies have already looked at air quality during the pandemic, this is the first to take a more rigorous view, using all 15 years of satellite data. It uses a statistical method that compares what was seen in February 2020 to what would have been expected without the pandemic."Early in the quarantine period, there was some discussion that the Earth was healing itself, but some of those claims, like the dolphins in Venice, have turned out to be false," Diamond said. "The scientific community was interested in documenting what changes actually occurred."The authors used data from NASA's Ozone Monitoring Instrument, or OMI, and Moderate Resolution Imaging Spectroradiometer, or MODIS, which have been monitoring the skies since 2005. These instruments use different wavelengths to monitor quantities like nitrogen oxides, airborne particulates and clouds.In addition to using a longer record, the model accounted for the expected effects of China's environmental policies."China passed a clean air law in 2013, and ever since you can see that pollution is going down. So just for that reason, we might expect that the pollution in 2020 would be lower than in 2019," Diamond said.The analysis also accounted for this past February's relatively hot and humid weather in China, which made gases more likely to react and form airborne particles."You still had some pretty bad smog events happening in the Beijing region, even during the lockdown," Diamond said.The authors also considered the atmospheric effects of the Chinese New Year, which is celebrated in either late January or early February and generates both higher particulates from fireworks and lower traffic emissions from people being on holiday.After accounting for all of these factors, the pandemic's effect on nitrogen oxides was a drop of 50% compared to what would be expected for February 2020, a drop unlike any other seen in the satellite observations."The difference we see is more than twice as large a drop as anything we saw in the record from 2005 to 2019, including from the 2008 Great Recession. In the statistics of atmospheric science, that's a giant signal. It is rare to see anything that striking," Diamond said.While the change in nitrogen dioxide was dramatic, other quantities showed no significant change. Fine particulate matter, which has a bigger impact on human health and the climate, hardly changed over China during the shutdown. Passenger transportation virtually disappeared during the lockdown, but economic data show that heavy industry and energy production stayed fairly constant, Diamond said.The fact that some quantities did not change is, for atmospheric scientists, a significant result in itself. Clouds, which are affected by pollution and have the biggest effect on climate, also showed no significant changes.Co-author Rob Wood, a UW professor of atmospheric sciences, and Diamond collaborated on a recent publication that detected cloud changes due to pollution from ships. That study showed that many years of data were required to detect the effect on clouds."Our study suggests that since we found little change in particulate pollution due to COVID-19, we are unlikely to see any change in the clouds unless pollution changes over a longer time period due to a prolonged economic downturn," Wood said.Overall, the findings agree with a recent study led by the UW showing that nitrogen dioxide dropped in several American cities during the peak quarantine period, but levels of other pollutants stayed fairly constant.The response suggests that future clean air policies can't focus only on transportation emissions."When you're crafting these clean air strategies, you're probably not going to be able to attack just one sector; you'll have to address several sectors at once," Diamond said.This research was funded by NASA.

Pollution

August 20, 2020

https://www.sciencedaily.com/releases/2020/08/200820102503.htm

Coronavirus SARS-CoV-2 spreads more indoors at low humidity

The airborne transmission of the coronavirus SARS-CoV-2 via aerosol particles in indoor environment seems to be strongly influenced by relative humidity. This is the conclusion drawn by researchers from the Leibniz Institute for Tropospheric Research (TROPOS) in Leipzig and the CSIR National Physical Laboratory in New Delhi from the analysis of 10 most relevant international studies on the subject. Therefore, they recommend controlling the indoor air in addition to the usual measures such as social distancing and masks. A relative humidity of 40 to 60 percent could reduce the spread of the viruses and their absorption through the nasal mucous membrane. To contain the COVID-19 pandemic, it is therefore extremely important to implement standards for indoor air humidity in rooms with many people, such as hospitals, open-plan offices or public transport, writes the research team in the scientific journal Aerosol and Air Quality Research.

According to the WHO, the coronavirus SARS-CoV-2 has led to at least 21 million infected persons and over 750,000 deaths worldwide in over half a year. The health and economic effects of the pandemic pose major social challenges for practically all countries. Worldwide, therefore, ways are being sought to stem the spread of the virus in order to avoid drastic measures such as lockdowns and contact restrictions. For a long time, the main transmission route of viral droplets was considered to be direct human-to-human contact, because of infected people sneezing or coughing and secreting the virus. Because these drops are relatively large and heavy, they fall very quickly to the ground and can only cover very short distances in the air. The recommendation to keep a minimum distance of 1.5m to 2m (social distancing) is based on this assumption. Recently, however, COVID-19 outbreaks have also been recorded, which seem to be due to the simultaneous presence of many people in one room (choir rehearsals, slaughterhouses, etc.). A safety distance of 1.5m is apparently not sufficient when infected and healthy people are together in one room for a long time. For example, Dutch researchers have now been able to prove that tiny drops of 5 micrometres in diameter, such as those produced when speaking, can float in the air for up to 9 minutes. In July, 239 scientists from 32 countries -- including the chemist Prof. Hartmut Herrmann from TROPOS -- therefore appealed to the World Health Organization (WHO) to focus more closely on the long-lived infectious particles suspended in the air. In order to contain the spread via the aerosol particles floating in the air, the researchers recommend not only continuing to wear masks but also, and above all, good indoor ventilation.An Indo-German research team is now pointing out another aspect that has received little attention so far and could become particularly important in the next flu season: Indoor humidity. Physicists at the Leibniz Institute for Tropospheric Research (TROPOS) in Leipzig and the CSIR National Physical Laboratory in New Delhi have been studying the physical properties of aerosol particles for years in order to better estimate their effects on air quality or cloud formation. "In aerosol research, it has long been known that air humidity plays a major role: The more humid the air is, the more water adheres to the particles and so they can grow faster. So, we were curious: what studies have already been conducted on this," explains Dr. Ajit Ahlawat from TROPOS.Therefore, they evaluated a total of 10 most relevant international studies between 2007 and 2020 by other researchers who investigated the influence of humidity on survival, spread and infection with the pathogens of influenza and the corona viruses SARS-CoV-1, MERS and SARS-CoV-2. Result: Air humidity influences the spread of corona viruses indoors in three different ways: (a) the behaviour of microorganisms within the virus droplets, (b) the survival or inactivation of the virus on the surfaces, and (c) the role of dry indoor air in the airborne transmission of viruses. Although, low humidity causes the droplets containing viruses to dry out more quickly, the survivability of the viruses still seems to remain high. The team concludes that other processes are more important for infection: "If the relative humidity of indoor air is below 40 percent, the particles emitted by infected people absorb less water, remain lighter, fly further through the room and are more likely to be inhaled by healthy people. In addition, dry air also makes the mucous membranes in our noses dry and more permeable to viruses," summarizes Dr. Ajit Ahlawat.The new findings are particularly important for the upcoming winter season in the northern hemisphere, when millions of people will be staying in heated rooms. "Heating the fresh air also ensures that it dries. In cold and temperate climate zones, therefore, the indoor climate is usually very dry during the heating season. This could encourage the spread of corona viruses," warns Prof. Alfred Wiedensohler of TROPOS. The air humidity determines how much water a particle can bind. At higher air humidity, the surface of the particles changes considerably: a kind of water bubble forms -- a miniature ecosystem with chemical reactions. The liquid water content of aerosols plays an important role in many processes in the atmosphere, as it influences the optical properties, leading for example to haze or altered effects of aerosols on the climate.At a higher humidity, the droplets grow faster, fall to the ground earlier and can be inhaled less by healthy people. "A humidity level of at least 40 percent in public buildings and local transport would therefore not only reduce the effects of COVID-19, but also of other viral diseases such as seasonal flu. Authorities should include the humidity factor in future indoor guidelines," demands Dr. Sumit Kumar Mishra of CSIR -- National Physical Laboratory in New Delhi. For countries in cool climates, the researchers recommend a minimum indoor humidity. Countries in tropical and hot climates, on the other hand, should take care that indoor rooms are not extremely undercooled by air conditioning systems. When air is extremely cooled, it dries out the air and the particles in it, making people inside the room feel comfortable. But the dry particles will remain in the air for longer duration.From a researchers' point of view, more attention should be paid to indoor air to prevent future outbreaks of viral disease. The moisture content of indoor air is an important aspect but not the only one. Fresh air from outside can also reduce the risk of transmission. And of course, the measures already known and practised: Keep social distancing, having as few people per room volume as possible, and wearing masks. The lowest risk of infection still where there are no viruses in the air.

Pollution

August 19, 2020

https://www.sciencedaily.com/releases/2020/08/200819194252.htm

Air pollution linked to higher risk of young children developing asthma

Children exposed to higher levels of fine particles in the air (known as PM2.5) are more likely to develop asthma and persistent wheezing than children who are not exposed, finds a study published by

Other risk factors associated with a higher risk of developing asthma and persistent wheezing were having parents with asthma, having a mother who smoked during pregnancy, or having parents with low education and low income.These findings support emerging evidence that exposure to air pollution might influence the development of asthma, say the researchers.PM2.5 can come from various sources, including power plants, motor vehicles and domestic heating. The particles (about 3% or less of the diameter of a human hair) can penetrate deep into the lungs and some may even enter the circulatory system.Short term peak exposure to air pollution has been associated with worsening of asthma, whereas the risks of long term exposure and the timing of exposure for the onset of asthma is less clear. In addition, the role of air pollution combined with other risk factors, such as socioeconomic status, on asthma is unclearSo researchers in Denmark set out to identify risk factors (air pollution and family related) for the onset of asthma and persistent wheezing in children.Their findings are based on more than three million Danish children born from 1997 to 2014 and followed for asthma onset and persistent wheezing from age 1 year to 15 years.Of these, 122,842 children were identified as having asthma and persistent wheezing (at an average age of 1.9 years).This information was then linked to detailed air pollutant measurements at the children's home addresses, parental asthma, maternal smoking, parental education and income.After taking account of other potentially influential factors, the researchers found higher levels of asthma and persistent wheezing in children of parents with asthma and in children of mothers who smoked during pregnancy.In contrast, lower levels of asthma and persistent wheezing were found in children of parents with high educational attainment and high incomes.Exposure to PM2.5 as well as larger particulate matter (PM10) NO2, and nitrate was associated with an increased risk of asthma and persistent wheezing. However, only the positive association of PM2.5 with asthma and persistent wheezing remained robust across the different models and after further (sensitivity) analyses.This is an observational study, so can't establish cause, and the researchers point to some limitations, such as a lack of information on nutrition and physical activity, and factors related to the children's indoor environment.However, strengths over previous studies include the large unselected number of children across all social classes and in a broad age group, and the use of high quality comprehensive data to minimise bias.As such, the researchers say their findings "support emerging evidence that exposure to air pollution might influence the development of asthma."While this finding needs to be substantiated in future studies, these results suggest that further reductions in PM2.5 "might help to reduce the number of children who develop asthma and persistent wheezing in highly exposed populations," they conclude.

Pollution

August 18, 2020

https://www.sciencedaily.com/releases/2020/08/200818142116.htm

This 'Cold Tube' can beat the summer heat without relying on air conditioning

Many people beat the summer heat by cranking the air conditioning. However, air conditioners guzzle power and spew out millions of tons of carbon dioxide daily. They're also not always good for your health -- constant exposure to central A/C can increase risks of recirculating germs and causing breathing problems.

There's a better alternative, say a team of researchers from the University of British Columbia, Princeton University, the University of California, Berkeley and the Singapore-ETH Centre.They call it the Cold Tube, and they have shown it works."Air conditioners work by cooling down and dehumidifying the air around us -- an expensive and not particularly environmentally friendly proposition," explains project co-lead Adam Rysanek, assistant professor of environmental systems at UBC's school of architecture and landscape architecture, whose work focuses on future energy systems and green buildings. "The Cold Tube works by absorbing the heat directly emitted by radiation from a person without having to cool the air passing over their skin. This achieves a significant amount of energy savings."The Cold Tube is a system of rectangular wall or ceiling panels that are kept cold by chilled water circulating within them. Since heat naturally moves by radiation from a hotter surface to a colder surface, when a person stands beside or under the panel, their body heat radiates towards the colder panel. This creates a sensation of cooling like cold air flowing over the body even if the air temperature is quite high.Although these types of cooling panels have been used in the building industry for several decades, what makes the Cold Tube unique is that it does not need to be combined with a dehumidification system. Just as a cold glass of lemonade would condense water on a hot summer day, cooling down walls and ceilings in buildings would also condense water without first drying out the air around the panels. The researchers behind the Cold Tube conceived of an airtight, humidity-repelling membrane to encase the chilled panels to prevent condensation from forming while still allowing radiation to travel through.The team built an outdoor demonstration unit last year in Singapore, inviting 55 members of the public to visit and provide feedback. When the system was running, most participants reported feeling "cool" or "comfortable," despite an average air temperature of 30 degrees Celsius (86 degrees Fahrenheit). The panels also stayed dry, thanks to the special membrane."Because the Cold Tube can make people feel cool without dehumidifying the air around them, we can look towards shaving off up to 50 per cent of typical air conditioning energy consumption in applicable spaces," said Eric Teitelbaum, a senior engineer at AIL Research who oversaw the demonstration project while working at the Singapore-ETH Centre."This design is ready. It can obviously be used in many outdoor spaces -- think open-air summer fairs, concerts, bus stops and public markets. But the mission is to adapt the design for indoor spaces that would typically use central air conditioning," he added.Beyond the energy savings, technologies like the Cold Tube have a great future, says project co-lead Forrest Meggers, an assistant professor at Princeton's school of architecture and the Andlinger Center for Energy and the Environment."Because the Cold Tube works independently of indoor air temperature and humidity, keeping windows open in our increasingly hot summers while still feeling comfortable becomes possible," said Meggers. "The Cold Tube can offer relief in different regions, from North American homes and offices that currently rely on standard HVAC systems to developing economies that foresee significant need for cooling in the coming half-century."There's another aspect of the Cold Tube that is particularly relevant in 2020, says Adam Rysanek."The COVID-19 pandemic has brought to the public's awareness how sensitive our health is to the quality of the air we breathe indoors. Specifically, we know that some of the safest spaces in this 'new normal' are outdoor spaces," said Rysanek. "As the climate changes and air conditioning becomes more of a global necessity than a luxury, we need to be prepared with alternatives that are not only better for the environment, but also our health. The idea of staying cool with the windows open feels a lot more valuable today than it did six months ago."The team is currently using the data collected in Singapore to update their projections of the Cold Tube's effectiveness in indoor spaces globally. They plan to demonstrate a commercially viable version of the technology by 2022.

Pollution