Saturday, February 08, 2020

A blanket ban on toxic 'forever chemicals' is good for people and animals

by Jonathan Van Hamme, The Conversation

Lowe's recently joined the Home Depot and other major retail chains in phasing out the sale of products treated with poly- and perfluoroalkyl substances, toxic chemicals more commonly known as PFAS. Specifically, Lowe's said it would stop selling indoor residential carpets and rugs treated with the PFAS by the end of 2019.

PFAS are a family of chemicals known for their non-stick, water-repellent and stain-resistant properties. They are used in cookware, clothing, carpets, cosmetics, and military and industrial applications.

But PFAS are persistent and have been detected in drinking water, in soil, rain, fog and ice, and in humans, plants and animals. Even polar bears and ringed seals in the Arctic have PFAS in their blood. A recent report found that almost all U.S. drinking water sources may be contaminated with PFAS, and the chemicals have been found to be widespread in Canadian rivers and creeks. Despite the evidence that PFAS cause a range of health problems, chemical companies often contradict those claims.

Although some countries have banned some types of PFAS, many remain on the market and new ones are regularly introduced. Perhaps it is time to ask whether wider bans on PFAS production and use are needed.

Non-stick for 80 years

PFAS are slow to break down in the environment. This stability can be traced to the strong bonds between fluorine atoms and chains of carbon atoms in the backbone of the molecules.

The first fluoropolymer was synthesized in Germany in 1934. It was soon followed by the accidental synthesis of polytetrafluoroethylene (PTFE) in 1938 by a chemist working for the chemical company DuPont. Within a few years PTFE was commercialized as the non-stick coating Teflon, and applied to everything from pans to paints.

Despite the history of PFAS, and the introduction of new products every decade since 1940, it was not until the turn of the century that PFAS manufacturers, academics and regulators had the analytical tools to begin to understand the pervasive nature of PFAS in the environment and the risks to human health.

Health problems

People are exposed to PFAS through food and water, and by inhaling dust. The chemical has been found in the blood of infants, young children and their mothers. Those working in the PFAS manufacturing industry or living near chemical plants have higher rates of exposure.

These compounds can build up, or bioaccumulate, in the tissues of people and other animals, with a preference for the liver, kidneys and blood. They are water soluble, meaning that they are excreted in urine, feces and in breast milk.

Research has linked PFAS to a variety of toxic effects, including liver damage, decreased fertility, thyroid disease, testicular and kidney cancer and a decreased immune response to vaccines. Growing concern about the potential health risks of PFAS has led some companies to discontinue their use.

On the manufacturing side, the 3M Company was the first to announce in 2000 that it would stop making perfluorooctane sulfonate (PFOS), the active compound in Scotchguard and other products, and one of the older types of PFAS. At the time, the U.S. Environmental Protection Agency said it was on the verge of taking steps to remove the product from market because of the risk it posed to the environment and human health.

Despite evidence to the contrary, including company records that have been made public in lawsuits, some in the chemical industry continue to argue that the chemicals do not pose human health risks.

Only a small fraction of PFAS have been tested for human health and safety before they were released to the market. With an estimated 3,000-5,000 untested PFAS being used in products today and only 75 PFAS identified by the EPA for future toxicity testing, it is not difficult to muddy the waters of evidence.

Regulations for public good

Hundreds of industrial, aviation and military sites across North America are contaminated with PFAS, and are at risk of polluting drinking water and food sources. By one estimate more than 110 million people in the U.S. may be drinking PFAS-contaminated water.

From a regulatory perspective, most of the attention has been placed on the two most common types, PFOS and perfluorooctanoic acid (PFOA).

Canada declared PFOS a toxic substance in 2008, and it was added to the Stockholm Convention on Persistent Organic Pollutants in 2009. The U.S. Environmental Protection Agency has been working with companies for more than a decade to stop the production and import of long-chain PFAS, including PFOS and PFOA.

The U.S. House of Representatives approved a bill in January that would regulate PFAS in drinking water, and the EPA has established a database to map the known health effects of PFAS. Although Canada lists drinking water screening values for 11 types of PFAS, it also warns that only "PFOS and PFOA have been studied sufficiently" to develop guidelines to protect Canadians' health.

Companies continue to introduce new types of PFAS they say are safer, although studies show that they may not be. In addition to the health risks these chemicals pose, they persist in the environment because they cannot be broken down by natural biochemical processes. As part of my research, I study bacteria and fungi that might be used to clean up environments contaminated with PFAS chemicals.

It is time for government to ban all long-chain PFAS, and forever eliminate these forever chemicals from our ecosystems.

Fecal excretion of PFAS by pets

Provided by The Conversation

SEE NC State researchers find high levels of firefighting foam chemical in Cape Fear bass

Framing the climate crisis as a terrorism issue could galvanize action

by Jennifer Zhang, Earth Institute, Columbia University

In many vulnerable regions of the world, the climate crisis has exacerbated loss of farmable land and increased water scarcity, fueling rural-urban migration, civil unrest, and violence. As a result, worsening geopolitical instability has aided the rise of terrorism and violence in the Middle East, Guatemala, and the Lake Chad Basin of Africa. Yet when people hear the words, "global warming," they typically don't think of terrorism. If they did, politicians would be far more likely to undertake drastic action to address the climate crisis.

Syria after 2011 is one example of how the climate crisis multiplied existing threats. Water scarcity, which had been worsening over the years, contributed significantly to the outbreak of conflict. The increased death of livestock, reduced arable land, and rise in food insecurity made it significantly easier for the terror organization calling itself the Islamic State of Iraq and Syria (ISIS) to locally recruit over two thirds of its fighters. Extreme weather phenomena offered ripe opportunities for ISIS to increase support among locals. When a vicious drought swept through Iraq in 2010, ISIS distributed food baskets to local inhabitants. When high winds destroyed vegetation in 2012, ISIS handed out cash to affected farmers. By offering a source of income and opportunity for people when their livelihoods were destroyed by droughts and other extreme weather, ISIS was able to cultivate support and draw members from local populations. In other words, the climate crisis increased geopolitical instability and aided the growth of terrorism.

The US is vehemently opposed to terrorism as a matter of national security. According to the Pew Research Center, in early 2018, over three-quarters of American adults believed terrorism should be a top policy priority for the government, the highest of any given option. Over 46 percent of American adults favored increasing spending on anti-terrorism defenses, though the US military budget is already larger than the next seven highest-spending countries combined. The same survey showed that less than half of American adults believed climate change should be a top policy priority, ranking the second lowest of given issues.

Most Americans see "global warming" as an environmental, scientific, and political issue. Over half of Americans do not see it as a national security issue. While it is informative to present the climate crisis primarily through scientific data on global temperatures, atmospheric carbon concentration, and emissions levels, it does not galvanize people to action nearly as much as characterizing it as a matter of immediate national security. Doing the latter would make it a much higher priority for people in power.

The U.S. military already quietly recognizes climate change as a matter of national security, in part because it sparks conflict and unrest in other countries. In order to conceptually link the climate crisis to national security for the broader public, climate activists should expand and increase rhetorical focus on how the climate crisis worsens migration, foments geopolitical instability, and thereby aids terrorist organizations. Presenting the climate crisis in security-centric concerns and consequences ensures that all Americans—including right-leaning voters and people who would not be swayed by conventional appeals to ecological conservation or species preservation—become aware of how consequential it is. Security-centric framing would also help to shift the tone of climate activism toward addressing immediate threats, rather than simply encouraging global cooperation for the sake of future generations.

Reorienting climate rhetoric around national security also brings the action to a level that feels more achievable—at the national rather than global level. Whereas preserving the planet for future generations sounds aspirational and spiritually uplifting, it is an intrinsically international goal that calls upon many countries to work together for success. Framing plans to deal with the climate crisis in a way that requires concerted goodwill tends to encourage cynicism and blame-shifting when countries fail to meet carbon emission reduction targets. The vast majority of countries are failing to lower emissions to levels that would keep global warming below 2 degrees Celsius, as the 2015 Paris Agreement aspires to do. This collective failure dissipates blame and often disincentivizes countries from shouldering the burdens of emission reduction. Furthermore, focusing overtly on country-level climate reduction targets conceals the fact that emissions are largely generated by a handful of international corporations—over a third of all carbon and methane emissions since 1965 have been produced by 20 companies, including Saudi Aramco, Chevron, Exxon Mobil, and Royal Dutch Shell.

Holding corporations accountable for emissions requires immense political momentum, which is more easily galvanized by framing climate action as a necessary defense against immediate danger than as a voluntary restriction of certain economic activities for global well-being. While global cooperation to reduce emissions is what the international community should strive for, using nation-centered rhetoric that focuses on security threats can be an effective conduit to achieving this broader goal. Furthermore, linking the climate crisis to terrorism could increase the motivation and capital for countries to press hard in climate negotiations; in the face of immediate danger, the inertia of other countries or companies seems a paltry excuse for inaction.

Saving nature vital to beating climate crisis, says WWF report

Just being around your cellphone affects your thinking, study finds

by Tim Christie, University of Oregon

As smart phones have become a pervasive part of daily life over the last decade or so, they've changed the way people socialize and communicate. They're always around and always within reach, or nearly always.

So what happens to people's brains and bodies when their phones are out of reach, or within reach but not usable?

That's what Dave Markowitz, assistant professor in the School of Journalism and Communication, and colleagues sought to find out in a recent study published in PLOS One, a peer-reviewed, open-access scientific journal.

Markowitz is interested in understanding the psychology of communication behavior, including language patterns and how media affects social and physical processes. As part of his doctoral thesis at Stanford University, he devised a study examining how subjects responded when exercising self-control with their phones.

He recruited 125 participants for the study, who were assigned to one of three groups and then directed to sit alone in an empty room for six minutes, though they weren't told the duration. Here's how the groups were divided up:

Members of one group were told to entertain themselves with their mobile phone, except no phone calls and no texting.
Members of the second group were told to leave their phones outside the room, sit alone without their device and entertain themselves with their thoughts.
Members of the third group were allowed to keep their phones but told to turn them face down on the table in front of them and not use them. They were also told to entertain themselves with their thoughts.

A fingertip device was used to measure skin conductance, an indicator of arousal. Participants' level of enjoyment, concentration difficulty, mind wandering and general mood were measured using post-study questionnaires.

Markowitz and colleagues found that participants without their phones had more difficulty concentrating and more mind wandering compared to those who used their phone. And those who had to resist using their phone had greater perceived concentration abilities than those who sat without their phone.

"The surprising finding for me was the reduction in concentration difficulty when people had to resist" using the phone, Markowitz said.

One possible reason that resisting the phone led to perceived improvement concentration? Most people think phones are valuable and seeing it front of them, even though they could not use it, offered something to think about compared to sitting without their phone, he said

"At least having it front of you was psychologically better than not having it all," he said. "Having some form of external stimulation, even if it wasn't used, I think that can focus the mind a bit.

It suggests having the phone present is better than not, but what's not clear is whether the phone is special, or if the participants would have reacted the same way with a book in front of them that they weren't allowed to read or pick up, he said.

Markowitz's findings fit with research by Tim Wilson at the University of Virginia, who found that when people were given time for "just thinking," they experience psychological consequences—less enjoyment, more difficulty concentrating, more mind wandering—compared to if they had some form of external stimulation.

"The mind can wander and lose focus when you're not given a thinking aid," which can be less psychologically positive for people, he said.

Markowitz said his study also fits in a framework of trying to understand if technology, or media in general, are mirrors or modifiers of human behavior.

If technology is a mirror, then mediated experiences reflect how people also act offline. If technology is a modifier, then in some cases it's changing the way we behave, think and feel in the world, he said.

"That's still really an open question," he said. "There are some cases where mediated and nonmediated experiences show consistencies in behavior, but other cases where mediation plays a crucial, modifying role. I'm interested in exploring these boundaries.

Put down the phone and live in the moment, says psychiatrist

More information: David M. Markowitz et al. Psychological and physiological effects of applying self-control to the mobile phone, PLOS ONE (2019). DOI: 10.1371/journal.pone.0224464

Biodiversity yields financial returns

IT WAS CALLED TRUCK FARMING IN THE THIRTIES

by Ori Schipper, ETH Zurich

A meadow with more than ten species yields more than a meadow with only one species. Credit: Valentin Klaus

Farmers could increase their revenues by increasing biodiversity on their land. This is the conclusion reached by an interdisciplinary research team including the fields of agricultural sciences, ecology and economics at ETH Zurich and other universities.

Many farmers associate grassland biodiversity with lower yields and financial losses. "Biodiversity is often considered unprofitable, but we show that it can, in fact, pay off," says Nina Buchmann, Professor of Grassland Sciences at ETH Zurich. In an interdisciplinary study at the interface of agricultural sciences, ecology and economics, Buchmann and her colleagues were able to quantify the economic added value of biodiversity based on a grassland experiment that examined different intensities of cultivation. Their paper has just been published in the journal Nature Communications.

Creating higher revenues

"Our work shows that biodiversity is an economically relevant factor of production," says Robert Finger, Professor of Agricultural Economics and Policy at ETH Zurich. If 16 different plant species grow in a field instead of just one, the quality of the forage remains more or less the same, but the yield is higher—which directly correlates to the income that can be made from milk sales. "The resultant increase in revenues in our study is comparable to the difference in yield between extensively and intensively farmed land," says Sergei Schaub, lead author of the study and a doctoral student in Finger's and Buchmann's groups.

Switzerland has so-called ecological compensation areas, i.e., grasslands for which farmers pay particular attention to promoting biodiversity. However, these areas often have poor soils and the yields they produce cannot be compared with those of high-quality grassland. Fortunately, the researchers were able to use data from the long-term Jena Experiment, which—among other questions—compared different farming practices at the same site.

"Our results show that biodiversity has an economically positive effect on all areas, regardless of whether farmers mow and fertilize them four times a year or just once," Schaub says. The more intensely the land is farmed, however, the more difficult it becomes to maintain a high level of biodiversity, because only a few plant species can withstand fertilization and frequent mowing, he notes. Finger adds that Swiss farmers already take more advantage of this economic effect than their counterparts in other countries. Generally speaking, biodiversity on the areas used for forage production in Switzerland is already relatively rich in biodiversity because the seed mixtures are adapted to local conditions, he explains.

Biodiversity as risk insurance

The researchers didn't expect their results to be so conclusive. And there's another economic aspect that they didn't even factor in: "Biodiversity is also a kind of risk insurance," Buchmann says. Diverse grasslands are better off to cope with extreme events such as droughts or floods, he explains, because different plant species react differently to such environmental influences, which partially compensates for any losses arising. "This means yields become more stable over time," Buchmann says, as the research team demonstrated in other recent studies.

The researchers believe their results are a clear indication that it's worthwhile for farmers to increase the diversity of plants growing on their land. "Preserving or restoring diverse grasslands can be a win-win situation," the researchers note at the end of their paper. Not only because this increases farmers' yields and operating revenues, but also because it improves and promotes important ecosystem services such as pollination or water quality.

Biological diversity as a factor of production

More information: Sergei Schaub et al. Plant diversity effects on forage quality, yield and revenues of semi-natural grasslands, Nature Communications (2020). DOI: 10.1038/s41467-020-14541-4

New material created to clean up fossil fuel industry

by University of Sydney

Researchers at the University of Sydney have created a new material that has the potential to reduce CO2 emissions released during the refinement process of crude oil by up to 28 percent.

Silica-alumina materials are among the most common solid acids that have been widely commercialised as efﬁcient and environmentally-friendly catalysts in the petrochemical and bio-reﬁnery industries.

In a world first, a team of researchers at the University of Sydney led by Associate Professor Jun Huang, have produced a new amorphous silica-alumina catalyst with stronger acidity than any other silica-alumina material created before.

"This new catalyst can significantly reduce the amount of CO2 emitted by oil refineries, which has the potential to make the fossil fuel industry much greener and cleaner," Associate Professor Huang from the Faculty of Engineering and Sydney Nano Institute said.

A significant amount of carbon is emitted during the refinement of crude oil to produce products like petroleum, gasoline and diesel. Estimates suggest 20 to 30 percent of crude oil is transferred to waste and further burnt in the chemical process, making oil refineries the second largest source of greenhouse gases behind power plants.

Credit: University of Sydney

Silica-aluminas with strong Brønsted acidity—a substance that gives up or donates hydrogen ions (protons) in a chemical reaction—are becoming increasingly important to various sustainability processes, including the fields of biomass conversion, CO2 capture and conversion, air-pollution remediation, and water purification.

"Renewable energy is important to achieving a more sustainable energy supply, but the reality is that we will still be reliant on fossil fuels in the foreseeable future. Therefore, we should do all we can to make this industry more efficient and reduce its carbon footprint while we transition to renewable energy sources

"This new catalyst offers some exciting prospects, if it were to be adopted by the entire oil refinery industry, we could potentially see a reduction of over 20 percent in CO2 emissions during the oil refinement process. That's the equivalent of double Australia's crude oil consumption, over 2 million barrels of oil per day."

"The new catalyst also has the potential to develop the biomass industry. We can now look to biomass material like algae to be part of sustainable energy solutions."

The next steps for the researchers are to work on manufacturing the new catalyst at a large, industrial scale.

A greener, simpler way to create syngas

More information: Zichun Wang et al. Acidity enhancement through synergy of penta- and tetra-coordinated aluminum species in amorphous silica networks, Nature Communications (2020). DOI: 10.1038/s41467-019-13907-7

A possible explanation for the mysterious ice circles in Lake Baikal

by Bob Yirka , Phys.org

A team of researchers affiliated with several institutions in Russia and one in France has found a possible explanation for the creation of ice circles in Lake Baikal—the deepest lake in the world. In their paper published in the journal Limnology and Oceanography, the group describes their two-year study of the ice circles and what they learned about them.

Approximately twenty years ago, scientists became aware of ice circles forming in different locations in Lake Baikal in the spring and summer months. The mysterious circles were so large that they could only be seen from airplanes or satellites. The initial suspicion was that they formed due to methane bubbling up from below. But testing showed no methane deposits below the lake.

The lake is located in Siberia, where it gets so cold that its surface freezes over completely during the winter months. The ice circles that have been observed have appeared in different sizes and different locations—but they are all characterized by a bright center surrounded by a dark circle. Prior research had shown them to be on average 5 to 7 kilometers in diameter. They also last from just a few days to a few months. Additional research showed that the ice rings were not exclusive to Lake Baikal—some were seen in Mongolia, in Lake Hovsgol and another in Russia's Lake Teletskoye. Such sightings suggested they likely appear in most deep lakes that freeze over during the winter. But there was still no explanation for how they formed.

Determined to find the answer, the researchers with this new effort traveled to the lake several times over the winters of 2016 and 2017. On each expedition, the drilled holes in the ice and dropped sensors into the lake where the circles were forming. They also studied infrared satellite images that revealed temperature variations in the lake. In February of 2016, the team found a possible clue—an eddy had formed in the water beneath the ice circle. And the water in the eddy was a couple of degrees warmer than the water around it. The researchers suggest the ice circles are formed due to water movement and temperature differences from surrounding water due to eddy formation. The following year the team found another eddy, this one without a circle above it. They suggested that they had spotted the eddy before a circle formed above it. They were not able to explain why the eddies were forming, however.

Image: Lake Baikal, Siberia

More information: Alexei V. Kouraev et al. Giant ice rings on lakes and field observations of lens‐like eddies in the Middle Baikal (2016–2017), Limnology and Oceanography (2019). DOI: 10.1002/lno.11338

Arctic ice melt is changing ocean currents

by Rexana Vizza / Matthew Segal, NASA

A major ocean current in the Arctic is faster and more turbulent as a result of rapid sea ice melt, a new study from NASA shows. The current is part of a delicate Arctic environment that is now flooded with fresh water, an effect of human-caused climate change.

Using 12 years of satellite data, scientists have measured how this circular current, called the Beaufort Gyre, has precariously balanced an influx of unprecedented amounts of cold, fresh water—a change that could alter the currents in the Atlantic Ocean and cool the climate of Western Europe.

The Beaufort Gyre keeps the polar environment in equilibrium by storing fresh water near the surface of the ocean. Wind blows the gyre in a clockwise direction around the western Arctic Ocean, north of Canada and Alaska, where it naturally collects fresh water from glacial melt, river runoff and precipitation. This fresh water is important in the Arctic in part because it floats above the warmer, salty water and helps to protect the sea ice from melting, which in turn helps regulate Earth's climate. The gyre then slowly releases this fresh water into the Atlantic Ocean over a period of decades, allowing the Atlantic Ocean currents to carry it away in small amounts.

But since the 1990s, the gyre has accumulated a large amount of fresh water—1,920 cubic miles (8,000 cubic kilometers) - or almost twice the volume of Lake Michigan. The new study, published in Nature Communications, found that the cause of this gain in freshwater concentration is the loss of sea ice in summer and autumn. This decades-long decline of the Arctic's summertime sea ice coverhas left the Beaufort Gyre more exposed to the wind, which spins the gyre faster and traps the fresh water in its current.

Persistent westerly winds have also dragged the current in one direction for over 20 years, increasing the speed and size of the clockwise current and preventing the fresh water from leaving the Arctic Ocean. This decades-long western wind is unusual for the region, where previously, the winds changed direction every five to seven years.

Scientists have been keeping an eye on the Beaufort Gyre in case the wind changes direction again. If the direction were to change, the wind would reverse the current, pulling it counterclockwise and releasing the water it has accumulated all at once.

"If the Beaufort Gyre were to release the excess fresh water into the Atlantic Ocean, it could potentially slow down its circulation. And that would have hemisphere-wide implications for the climate, especially in Western Europe," said Tom Armitage, lead author of the study and polar scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.

Fresh water released from the Arctic Ocean to the North Atlantic can change the density of surface waters. Normally, water from the Arctic loses heat and moisture to the atmosphere and sinks to the bottom of the ocean, where it drives water from the north Atlantic Ocean down to the tropics like a conveyor belt.

This important current is called the Atlantic Meridional Overturning Circulation and helps regulate the planet's climate by carrying heat from the tropically-warmed water to northern latitudes like Europe and North America. If slowed enough, it could negatively impact marine life and the communities that depend it.

"We don't expect a shutting down of the Gulf Stream, but we do expect impacts. That's why we're monitoring the Beaufort Gyre so closely," said Alek Petty, a co-author on the paper and polar scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

The study also found that, although the Beaufort Gyre is out of balance because of the added energy from the wind, the current expels that excess energy by forming small, circular eddies of water. While the increased turbulence has helped keep the system balanced, it has the potential to lead to further ice melt because it mixes layers of cold, fresh water with relatively warm, salt water below. The melting ice could, in turn, lead to changes in how nutrients and organic material in the ocean are mixed, significantly affecting the food chain and wildlife in the Arctic. The results reveal a delicate balance between wind and ocean as the sea ice pack recedes under climate change.

"What this study is showing is that the loss of sea ice has really important impacts on our climate system that we're only just discovering," said Petty.

Arctic ice sets speed limit for major ocean current

More information: Thomas W. K. Armitage et al. Enhanced eddy activity in the Beaufort Gyre in response to sea ice loss, Nature Communications (2020). DOI: 10.1038/s41467-020-14449-z

Scientists resurrected a Wrangel Island mammoth's mutated genes

by Charlotte Hsu, University at Buffalo

Scientists resurrect mammoth’s broken genes — Credit: Rebecca Farnham / University at Buffalo

Some 4,000 years ago, a tiny population of woolly mammoths died out on Wrangel Island, a remote Arctic refuge off the coast of Siberia.

They may have been the last of their kind anywhere on Earth.

To learn about the plight of these giant creatures and the forces that contributed to their extinction, scientists have resurrected a Wrangel Island mammoth's mutated genes. The goal of the project was to study whether the genes functioned normally. They did not.

The research builds on evidence suggesting that in their final days, the animals suffered from a medley of genetic defects that may have hindered their development, reproduction and their ability to smell.

The problems may have stemmed from rapid population decline, which can lead to interbreeding among distant relatives and low genetic diversity—trends that may damage a species' ability to purge or limit harmful genetic mutations.

"The key innovation of our paper is that we actually resurrect Wrangel Island mammoth genes to test whether their mutations actually were damaging (most mutations don't actually do anything)," says lead author Vincent Lynch, Ph.D., an evolutionary biologist at the University at Buffalo. "Beyond suggesting that the last mammoths were probably an unhealthy population, it's a cautionary tale for living species threatened with extinction: If their populations stay small, they too may accumulate deleterious mutations that can contribute to their extinction."

The study was published on Feb. 7 in the journal Genome Biology and Evolution.

Lynch, an assistant professor of biological sciences in the UB College of Arts and Sciences, joined UB in 2019 and led the project while he was at the University of Chicago. The research was a collaboration between Lynch and scientists at the University of Chicago, Northwestern University, University of Virginia, University of Vienna and Penn State. The first authors were Erin Fry from the University of Chicago and Sun K. Kim from Northwestern University.

To conduct the study, Lynch's team first compared the DNA of a Wrangel Island mammoth to that of three Asian elephants and two more ancient mammoths that lived when mammoth populations were much larger.

The researchers identified a number of genetic mutations unique to the Wrangel Island mammoth. Then, they synthesized the altered genes, inserted that DNA into cells in petri dishes, and tested whether proteins expressed by the genes interacted normally with other genes or molecules.

The scientists did this for genes that are thought or known to be involved in a range of important functions, including neurological development, male fertility, insulin signaling and sense of smell.

In the case of detecting odors, for example, "We know how the genes responsible for our ability to detect scents work," Lynch says. "So we can resurrect the mammoth version, make cells in culture produce the mammoth gene, and then test whether the protein functions normally in cells. If it doesn't—and it didn't—we can infer that it probably means that Wrangel Island mammoths were unable to smell the flowers that they ate."

The research builds on prior work by other scientists, such as a 2017 paper in which a different research team identified potentially detrimental genetic mutations in the Wrangel Island mammoth, estimated to be a part of a population containing only a few hundred members of the species.

"The results are very complementary," Lynch says. "The 2017 study predicts that Wrangel Island mammoths were accumulating damaging mutations. We found something similar and tested those predictions by resurrecting mutated genes in the lab. The take-home message is that the last mammoths may have been pretty sick and unable to smell flowers, so that's just sad.

The last mammoths died on a remote island

More information: Erin Fry et al. Functional architecture of deleterious genetic variants in the genome of a Wrangel Island mammoth, Genome Biology and Evolution (2019). DOI: 10.1093/gbe/evz279

New commuter concern: Cancerous chemical in car seats

by University of California - Riverside

The longer your commute, the more you're exposed to a chemical flame retardant that is a known carcinogen and was phased out of furniture use because it required a Proposition 65 warning label in California.

That is the conclusion of a new UC Riverside study published this month in the journal Environment International.

While much research on automobile pollution focuses on external air pollutants entering vehicle interiors, this study shows that chemicals emanating from inside your car could also be cause for concern.

Though there are other Proposition 65-list chemicals that are typically used in the manufacture of automobiles, this flame retardant is a new addition to the list. Known as the Safe Drinking Water and Toxic Enforcement Act, Proposition 65 requires the state to maintain and update a list of chemicals known to cause cancer or reproductive harm.

Some scientists assumed that humans stopped being exposed to the chemical, called TDCIPP or chlorinated tris, after it was placed on California's Proposition 65 list in 2013. However, it is still widely used in automobile seat foam. The study shows that not only is your car a source of TDCIPP exposure, but that less than a week of commuting results in elevated exposure to it.

David Volz, associate professor of environmental toxicology at UCR, said the results were unexpected.

"I went into this rather skeptical because I didn't think we'd pick up a significant concentration in that short a time frame, let alone pick up an association with commute time," Volz said. "We did both, which was really surprising."

Over the past decade, Volz has studied how various chemicals affect the trajectory of early development. Using zebrafish and human cells as models, the Volz laboratory has been studying the toxicity of a newer class of flame retardants called organophosphate esters since 2011.

Little is known about the toxicity of these organophosphate esters—TDCIPP is one of them—but they've replaced older flame-retardant chemicals that lasted longer in the environment and took longer to metabolize.

Using zebrafish as a model, Volz found TDCIPP prevents an embryo from developing normally. Other studies have reported a strong association between TDCIPP and infertility among women undergoing fertility treatments.

Knowing its use is still widespread in cars, Volz wondered whether a person's exposure is elevated based on their commute. UC Riverside undergraduates made for excellent study subjects, as a majority of them have a daily commute.

The research team included collaborators at Duke University and was funded by the National Institutes of Health as well as the USDA National Institute of Food and Agriculture.

Participants included around 90 students, each of whom had commute times that varied from less than 15 minutes to more than two hours round trip. All of them were given silicone wristbands to wear continuously for five days.

The molecular structure of silicone makes it ideal for capturing airborne contaminants. Since TDCIPP isn't chemically bound to the foam, Aalekyha Reddam, a graduate student in the Volz laboratory, said it gets forced out over time and ends up in dust that gets inhaled.

Multiple organophosphate esters were tested, but TDCIPP was the only one that showed a strong positive association with commute time.

"Your exposure to TDCIPP is higher the longer you spend in your vehicle," Reddam said.

While Volz and his team did not collect urine samples to verify that the chemical migrated into the bodies of the participants, they believe that's what happened.

"We presume it did because of how difficult it is to avoid the ingestion and inhalation of dust," Volz said. Additionally, other studies have examined the accumulation of TDCIPP in urine, but not as a function of how long a person sits in a car.

Going forward, the research team would like to repeat the study with a larger group of people whose ages are more varied. They would also like to study ways to protect commuters from this and other toxic compounds.

Until more specific reduction methods can be identified, the team encourages frequently dusting the inside of vehicles, and following U.S. Environmental Protection Agency guidelines for reducing exposure to contaminants.

Until safer alternatives are identified, more research is needed to fully understand the effects of TDCIPP on commuters.

"If we picked up this relationship in five days, what does that mean for chronic, long-term exposure, for people who commute most weeks out of the year, year over year for decades?" Volz asked.

Pet tags link widely used flame retardant to hyperthyroidism in cats

More information: Aalekhya Reddam et al, Longer commutes are associated with increased human exposure to tris(1,3-dichloro-2-propyl) phosphate, Environment International (2020). DOI: 10.1016/j.envint.2020.105499

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