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Wildfires And Cancer Risk | Earth Wise

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Hotter and drier conditions are leading to an increasing number of wildfires in North America and elsewhere around the globe.  Scientists have linked the severe heat and drought that fuel these wildfires to climate change. As the climate continues to change, wildfires are projected to become more prevalent, more severe, and longer in duration. 

According to a United Nations report released earlier this year, the Western U.S., northern Siberia, central India, and eastern Australia have already seen an uptick in wildfires.  The likelihood of catastrophic wildfires globally could increase by a third by 2050 and more than 50% by the turn of the century. 

According to a new study by researchers from McGill University, living near regions prone to wildfires may boost the risk of developing serious health issues.  The study, which tracked more than two million Canadians over a period of 20 years, found a higher incidence of lung cancer and brain tumors in people exposed to wildfires.  People living within 50 kilometers of wildfires during the past 10 years had a 10% higher incidence of brain tumors and a 4.9% higher incidence of lung cancer when compared to people living further away. 

This study, which was recently published in The Lancet Planetary Health, is the first to examine how proximity to forest fires may influence cancer risk.

In addition to the impacts on air quality, wildfires also pollute aquatic, soil, and indoor environments.  While some pollutants return to normal levels shortly after the fire, many others persist in the environment for long periods of time. 

The research team notes that additional work is needed to develop more long-term estimates of the chronic health effects of wildfires.

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Exposure to wildfires increases risk of cancer

Climate change is causing more wildfires and governments are unprepared, says U.N.

Photo, posted August 17, 2020, courtesy of USFS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Methane Leaks Are Worse Than We Thought | Earth Wise

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Methane leaking from oil and gas wells is a real problem for the environment because methane is far more potent at trapping heat than carbon dioxide.   The EPA has estimated that about 1.4% of the methane produced by wells nationally leaks into the atmosphere.   However, environmental experts and energy industry engineers have been concerned that leaks from mines, wells, refineries, storage facilities, and pipelines are vastly underreported.  But until recently, there really wasn’t a good way to find out.

Researchers at Stanford University have developed a technique based on the use of hyperspectral cameras mounted to airplanes.  The cameras measure sunlight reflected off of chemicals in the air that are invisible to the human eye.  Each chemical, including methane, has a unique fingerprint.  Using these sensors, methane is easy to spot and the technique can measure the output of individual wells.

The researchers performed a study of almost every oil and gas asset in the New Mexico Permian Basin, one of the largest and highest-producing oil and gas regions in the world.  They surveyed the sites for an entire year.  They estimate that more than 9% of all methane produced in the region is being leaked into the skies, far more than EPA estimates.

The positive outcome of the survey is that the researchers found that fewer than 4% of the 26,000 sites studied produced half of all the methane emissions observed.  Being able to identify the so-called super-emitter sites and dealing with them could lead to a major improvement in the situation.

The new technique is more accurate, faster, and more cost-effective than current ways to monitor emissions.

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Stanford-led study: Methane leaks are far worse than estimates, at least in New Mexico, but there’s hope

Photo, posted July 10, 2016, courtesy of Ken Lund via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Better Way To Capture Carbon | Earth Wise

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The goal of carbon capture and storage technology is to remove carbon dioxide from the atmosphere and safely store it for the indefinite future.  There are existing industrial facilities that capture carbon dioxide from concentrated sources – like the emissions from power plants.  The technology currently captures and stores only about a tenth of a percent of global carbon emissions.

Most existing CCS technologies use chemical binders to trap carbon dioxide quickly and efficiently, but they are extraordinarily energy intensive as well as expensive.

Researchers at the University of Colorado Boulder have developed a new tool that could lead to more efficient and cheaper ways to capture carbon dioxide directly out of the air.  The tool predicts how strong the bond will be between carbon dioxide and a candidate molecule for trapping it – that is, a binder.  This new electrochemical diagnostic tool can be used to identify suitable molecular candidates for capturing carbon dioxide from everyday air.

Current carbon capture technologies are very expensive at the scale required to be able to turn the captured CO2 into useful substances, such as carbonates – which are an ingredient in cement – or formaldehyde or methanol, which can be used as fuels.  Making useful materials out of the captured CO2 is an important way to offset the cost of capturing it that merely storing it away does not permit.

The new electrochemical analytical tool developed by the Colorado researchers offers the potential for identifying binders that will be more efficient and less expensive, thereby making direct air carbon capture a realistic part of the efforts to address climate change.

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New method could lead to cheaper, more efficient ways to capture carbon

Photo, posted October 25, 2015, courtesy of Frans Berkelaar via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Getting Rid Of Single-Use Plastics | Earth Wise

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Single-use plastics are used only once before they are recycled – or more likely – simply thrown away.  These are things like plastic bags, straws, coffee stirrers, soda and water bottles, and most food packaging.  They are primarily made from fossil fuel-based chemicals.

Since the 1950s, over 9 billion tons of plastics have been produced, and half of that has been in the past 15 years.  There are uses for plastic that are not only reasonable, but are even important, such as for surgical gloves.  But for the most part, single-use plastic is the poster child of our throwaway culture that is bad for the environment, for wildlife, and even for human health.

Many cities, states, and even countries are moving toward greatly limiting or outright banning single-use plastics.  A recent global survey indicates that the great majority of people around the world are with the program.

According to a 28-country survey from marketing firm Ipsos and the activist group Plastic Free July, three out of four people around the world agree with a ban on single-use plastics.  The poll of more than 20,000 people showed that in Latin America, China, and India, more than 80% agree that a ban should happen as soon as possible.  Unfortunately, Canada, the United States, and Japan were the least supportive countries.  In particular, only 40% of Japanese respondents favored a ban.

Ninety percent of respondents globally support an international treaty to combat plastic pollution and eighty percent said they personally want to buy products with as little plastic packaging as possible.  Unfortunately, people in wealthy countries, which produce the most plastic waste, are less likely to support a ban.  Those countries typically export their waste to the developing world.

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Three in Four People Worldwide Support a Ban on Single-Use Plastics

Photo, posted April 13, 2006, courtesy of Leonard J Matthews via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Dangers Of Thawing Permafrost | Earth Wise

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The thawing of the permafrost in the Arctic is a major concern from the standpoint of the potential release of enormous amounts of carbon dioxide trapped in it.  There are nearly 2,000 billion tons of carbon there, which is as much as humanity releases into the atmosphere in 50 years.  But greenhouse gases are not the only danger posed by permafrost thawing.  There are also microbes, unknown viruses, and chemicals that could be very dangerous.

More than 100 diverse microorganisms in Siberia’s deep permafrost have been found to be antibiotic resistant.  The deep permafrost is one of the few environments on Earth that have not been exposed to modern antibiotics.  As the permafrost thaws, its bacteria could mix with meltwater and create new antibiotic-resistant strains.

By-products of fossil fuels – introduced into permafrost environments since the beginning of the industrial revolution – are present.  Metal deposits including arsenic, mercury, and nickel, have been mined for decades and have contaminated large areas.

Now-banned pollutants and chemicals – including DDT – came to the Arctic through the atmosphere and over time have become trapped in the permafrost.

There is now ongoing research further characterizing the microbes frozen in permafrost and providing more precise measurement of emissions hotspots in permafrost regions.  Scientists are increasingly turning to integrated Earth observations from the ground, the air, and space.

There are models that predict the gradual release of emissions from permafrost over the next century.  Other models say it could happen within just a few years.  The worst-case scenario would be utterly catastrophic but none of the scenarios portend anything good.

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Thawing Permafrost Could Leach Microbes, Chemicals Into Environment

Photo, posted February 9, 2017, courtesy of Benjamin Jones/USGS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Americans And Lead Exposure | Earth Wise

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Long-term exposure to lead can cause serious health problems, especially in children.  Children are particularly vulnerable because their early years are characterized by rapid growth and brain development.

Lead is a powerful neurotoxin that can cause damage even at low levels of exposure.  Lead poisoning can be acute, and can cause all sorts of health issues, including stomach pain, brain damage, and even death.  Because lead accumulates in the body over time, lead poisoning can develop slowly. Exposure to lead can also contribute to a lower IQ and behavioral problems that can last a lifetime.

Lead is a naturally occurring element found in small amounts in earth’s crust.  But as a result of human activities, lead can be found in all parts of the environment, including the air, soil, and water.

According to a new study recently published in the journal Proceedings of the National Academy of Sciences, approximately half of U.S. adults alive today were exposed to harmful levels of lead as children from the burning of leaded gasoline.  The research team estimates that lead contamination has lowered those Americans’ IQ scores by more than two points on average.

In the study, the researchers used data on childhood blood-lead levels, leaded gasoline use, and population to gauge the lifetime exposure of every American adult in 2015.  They found that more than 170 million Americans had exposure to concerning levels of lead as children.  Those who grew up in the 60s and 70s, when the burning of leaded gasoline was at its peak, had the greatest exposure, losing up to six IQ points on average. 

The legacy of lead exposure remains a persistent problem.

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Half of Americans Exposed to Harmful Levels of Lead as Children

Lead Exposure Remains A Persistent Problem

Photo, posted February 13, 2010, courtesy of Steve Snodgrass via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Greenhouse Gas Removal And Net Zero | Earth Wise

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Reducing the amount of greenhouse gas emissions can slow the progress of global warming but only reaching and sustaining net zero global emissions can halt the progress of climate change.

The move to renewable power and the use of electric transport are substantial and essential ways to reduce emissions.  But even if these transitions take place on a rapid timescale, they will not eliminate all emissions.  Many industrial activities and, especially, agriculture will continue to contribute substantial greenhouse gas emissions.   There are efforts to reduce the contributions of these things, but there are no zero-emission substitutes for most of them.

As a result, actually removing CO2 from the atmosphere once it is there is essential to achieve net zero emissions.  If greenhouse gas removal can be scaled up sufficiently, it opens the option of going “net negative”, which would be the ideal way to mitigate and, better still, reverse the effects of climate change.

There are multiple approaches to carbon dioxide removal.  Some are natural, involving ways of capturing and storing carbon in trees, biochar, and peatlands.  Others are technological.  An example is the system that has just gone into operation in Iceland that uses fans, chemicals, and heat to capture CO2 and then mineralize it in volcanic rock.   Another is a system being tested in the UK that captures CO2 from growing biomass and pipes it to storage under the North Sea.

Much of the attention on carbon capture technology is aimed at trapping the emissions from fossil fuel power plants, but the need to remove carbon dioxide that has entered the atmosphere in other ways is ultimately far greater.

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CO2 removal is essential to achieving net zero

Photo, posted August 17, 2013, courtesy of Joshua Mayer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cleaner Water Using Corn | Earth Wise

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Corn is the largest agricultural crop in the U.S., and it is also one of the most wasteful.  About half of the harvest ends up as stover – corn stalks, leaves, husks, and cobs – once the kernels are used for food.

Corn stover has relatively few commercial or industrial uses.  It can be used to produce biofuel, but that is not very energy efficient.  It is sometimes used as a low-quality livestock feed as well.  Mostly, it is just burned if it is used at all.

Researchers at the University of California Riverside have developed an energy-efficient way to make good use of stover by transforming it into activated carbon for use in water treatment.

Activated carbon – often called activated charcoal – is an organic material that is specially treated to contain millions of microscopic pores that make it highly absorbent.  It has many industrial uses, the most common of which is for filtering pollutants out of drinking water.  Most household water filters such as Brita filters as well as the ones built into refrigerators make use of activated carbon.

The Riverside researchers explored methods for producing activated carbon from charred corn stover and found that processing the material with hot compressed water – a process known as hydrothermal carbonization – produced highly absorbent activated carbon with superior properties compared to material produced by slow pyrolysis, where corn stover is charred at increasing temperatures over a long period of time.

According to the researchers, it is important to create approaches that convert waste into high-value materials, fuels, and chemicals in order to create new value streams and eliminate the environmental harm that comes from a so-called “take-make-dispose” economic model.

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Cleaner Water Through Corn

Photo, posted September 15, 2010, courtesy of the United Soybean Board / the Soybean Checkoff via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Wood Into Plastic | Earth Wise

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Plastic pollution is particularly pernicious because plastics can take hundreds of years to degrade in the environment.  For this reason, researchers across the globe search for ways to shift from petrochemical plastics to ones that are biodegradable.

Producing biodegradable plastics is challenging both from the standpoint of the methods needed and from the results obtained.  Producing them often requires toxic chemicals and can be very expensive.  The materials that emerge often do not have the durability and strength of conventional plastics and can be unstable when exposed to moisture.

Researchers at the Yale School of the Environment have developed a process of decomposing the porous matrix of natural wood into a slurry that can be formed into a biodegradable plastic.  The material shows high mechanical strength, stability when holding liquids, and is resistant to the effects of ultraviolet light.  Along with all these favorable properties, the material can be recycled or safely biodegraded in the natural environment.

The slurry mixture is created by taking wood powder – a processing residue usually discarded in lumber mills – and deconstructing it with a biodegradable and recyclable solvent.  The resulting mixture has a high solid content and high viscosity and can be casted and rolled without breaking.

The researchers conducted a comprehensive life cycle assessment to test the environmental impacts of the bioplastic compared with conventional plastics.  Sheets of it were buried in soil and observed to fracture after two weeks and completely degrade after three months.  The material can also be broken back down into the slurry by mechanical stirring.

The remaining topic to investigate is the potential impact on forests if the manufacturing of this bioplastic is scaled up.

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Turning wood into plastic

Photo, posted October 12, 2016, courtesy of the US Forest Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Superstrong Nanofibers | Earth Wise

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Self-assembly is a ubiquitous process in the natural world that leads to the formation of the DNA double helix, the creation of cell membranes, and to many other structures.   Scientists and engineers have been working to design new molecules that assemble themselves in water for the purpose of making nanostructures for biomedical applications such as drug delivery or tissue engineering.  For the most part, the materials created in this way have been chemically unstable and tended to degrade rapidly, especially when the water is removed.

A team at MIT recently published a paper describing a new class of small molecules they have designed that spontaneously assemble into nanoribbons with unprecedented strength and that retain their structure outside of water.

The material is modeled after a cell membrane.  Its outer part is hydrophilic (it likes to be in water) and its inner part is hydrophobic (it tries to avoid water.)  This configuration drives the self-assembly to create a specific nanostructure and by choosing the appropriate chemicals to form the structures, the result was nanoribbons in the form of long threads that could be dried and handled.  The resultant material in many ways resembles Kevlar.   In particular, the threads could hold 200 times their own weight and have extraordinarily high surface areas.  The fibers are stronger than steel and the high surface-to-mass ratio offers promise for miniaturizing technologies for such applications as pulling heavy-metal contaminants out of water and for use in electronic devices and batteries.

The goal of the research is to tune the internal state of matter to create exceptionally strong molecular nanostructures.  The potential for important new applications is considerable and exciting.

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Researchers construct molecular nanofibers that are stronger than steel

Photo, posted June 19, 2007, courtesy of Andrew Hitchcock via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Food Waste Back Into Food | Earth Wise

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Scientists at the University of California Riverside have discovered that fermented food waste can boost bacteria that increase crop growth, make plants more resistant to pathogens, and reduce the carbon emissions resulting from farming.

Food waste is a serious problem from multiple perspectives.  As much as 50% of food is thrown away in the United States and most of that simply ends up in landfills, taking up more than 20% of America’s landfill volume.  Food waste is a huge economic loss as well as a significant waste of freshwater resources used to produce food.

The researchers studied byproducts from two kinds of food waste readily available in Southern California:  beer mash – a byproduct of beer production – and mixed food waste discarded by grocery stores.

Both types of waste were fermented and then added to the irrigation system watering citrus plants in a greenhouse.  Within 24 hours, the average population of beneficial bacteria was two to three orders of magnitude greater than in plants that did not receive the treatments. This led to improvements in the carbon to nitrogen ratio in crops.  When there are enough so-called good bacteria in plants, they produce antimicrobial compounds and metabolites that help plants grow better and faster.

The results of the study suggest that the use of food waste products in agriculture is beneficial and could complement the use of synthetic chemical additives by farmers, perhaps eliminating it entirely.  Crops would in turn become less expensive.

Making use of food waste in agriculture is a step towards a more circular economy in which we use something and then find a new purpose for it.

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Turning food waste back into food

Photo, posted October 28, 2012, courtesy of Daniel Lobo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Shifting Climate Attitudes – Even In Texas | Earth Wise

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Any conversation about climate policy and energy in the United States has to take Texas into consideration.  Texas leads the nation in energy production, providing more than one-fifth of U.S. domestically produced energy.  Texas also uses more energy than any other state and accounts for almost one-seventh of total U.S. energy consumption.  The state’s industrial sector, which includes petroleum refining and chemical manufacturing, accounts for almost half of Texas energy consumption.

As a result, longstanding skepticism among Texans toward the climate movement has represented a real impediment in developing and implementing effective climate policy in this country.  But according to new research at the University of Houston, attitudes in Texas have changed and now mirror those in the rest of the United States.

About 80% of Americans believe that climate change is happening, and now about 81% of Texans hold the same view.  Two out of three Americans are worried about climate change; more than 60% of Texans agree.

Nationwide, 55% agree that the oil and gas industries have deliberately misled people on climate change; 49% of Texans agree. 64% of Americans say hydraulic fracking has a negative effect on the environment and 61% of Texans agree.  People everywhere are willing to pay more for carbon-neutral energy, and a higher premium for gasoline as well.

Mitigation strategies for climate change are not well understood.  While 61% nationwide have heard of carbon taxes, less than half are familiar with carbon management, and only a third have heard of carbon pricing.

As the U.S. heads toward reengaging in efforts to address climate change, Texans appear to have caught up with the rest of the nation.

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Attitudes About Climate Change Are Shifting, Even in Texas

Photo, posted October 1, 2011, courtesy of Steve Rainwater via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildfires And Superfund Sites | Earth Wise

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Thousands of contaminated sites exist nationally due to hazardous waste being dumped, left out in the open, or otherwise improperly managed. These sites include manufacturing facilities, processing plants, landfills, and mining sites.  A Congressional act in 1980 established authority by the EPA to ultimately clean up these “Superfund” sites.

According to a government survey last year, 945 Superfund sites are vulnerable to hurricanes, flooding, sea level rise, increased precipitation, or wildfires, all of which are intensifying as the climate warms.   In particular, there are 245 sites vulnerable to wildfires and 68 of them have recently seen wildfires approach.

A comprehensive investigation by Inside Climate News, NBC News, and the Texas Observer has found that the threat presented by wildfires is exceeding authorities’ ability to adequately prepare and respond.  Fires at Superfund sites could release toxins ranging from acid mine drainage to radioactive smoke.

There have already been a number of close calls.  The 2013 Patch Springs Fire near Salt Lake City came within 10 miles of the Tooele Army Depot, a Superfund site with 902 ammunition bunkers along with soil and groundwater contaminated with hazardous chemicals.

The 2018 Carr Fire in Northern California over swept the Iron Mountain Mine Superfund site and threatened to release corrosive chemicals into the watershed.

For sites where no polluter can be made to pay and the EPA lacks cleanup funds, the agency will need to design protections that shield the sites from wildfires as long as the contamination remains. 

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Fueled by Climate Change, Wildfires Threaten Toxic Superfund Sites

Photo, posted July 26, 2018, courtesy of the Bureau of Land Management California via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Finding Plastic In Seafood | Earth Wise

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Researchers from the University of Exeter in the UK and the University of Queensland in Australia have developed a new method for identifying and measuring the presence of five different types of plastic in seafood.

The researchers purchased oysters, prawns, squid, crabs, and sardines from a market in Australia and analyzed them using the new technique.  They found plastic in every single sample.

Their findings showed that the amount of plastics present varies greatly among species and differs between individuals of the same species.  The measured plastic levels were 0.04 mg per gram of seafood in squid, 0.07 mg in prawns, 0.1 mg in oysters, 0.3 mg in crabs, and 2.9 mg in sardines. 

All the plastics are types commonly used in plastic packaging and synthetic textiles and are increasingly found in marine litter:  polystyrene, polyethylene, polyvinyl chloride, polypropylene, and polymethyl methacrylate.

The new method treats the seafood tissues with chemicals that dissolve the plastics present within them.  The resulting solution is then analyzed using a highly sensitive technique called Pyrolysis Gas Chromatography Mass Spectrometry which both identifies and quantifies the plastics.

Microplastics are an increasing source of pollution for much of the planet, including the oceans where they are eaten by all types of marine creatures ranging from planktonic organisms to large mammals.  Microplastics enter our diet not only from seafood, but also from bottled water, sea salt, beer, and honey, as well as from dust that settles on our food.

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Seafood study finds plastic in all samples

Photo, posted June 23, 2007, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Livestock Expansion And Global Pandemics | Earth Wise

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The domestication of cows, pigs, chickens, and other animals as livestock for their meat, milk, and eggs was historically revolutionary.  It boosted food security by giving people a readily-available means of feeding themselves as opposed to more traditional methods such as hunting and fishing. 

But animal agriculture has plenty of drawbacks.  The industrialization of animal agriculture has led to horrendous conditions.  Animals are kept in huge quantities and packed together with little regard for their health and welfare.  This approach to agriculture is simply designed to maximize production while minimizing costs. 

With its chemical inputs and toxic outputs, intensive animal agriculture is also a major threat to the environment.  In fact, it’s a major driver of habitat degradation and biodiversity loss all around the globe.   

But it’s not just animals and the planet that pay a price.  Humans have inherited several lethal pathogens from livestock over the years, including the influenza virus that likely jumped to humans from poultry.

According to a study recently published in Biological Conservation,  there is a connection between the global increase in the emergence of infectious diseases and epidemics, the accelerated loss of biodiversity, and the expansion of livestock.  In the study, the research team from the Institute of Evolution Sciences of Montpellier cross referenced databases on human and animal health, livestock expansion, and biodiversity loss between 1960-2019.  The team found that the number of epidemics identified in humans increased in correlation with both biodiversity loss and livestock expansion. 

In the era of COVID-19, it’s important to understand how global livestock expansion directly threatens both human health and the health of the planet. 

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Livestock expansion is a factor in global pandemics

Photo, posted July 22, 2018, courtesy of Artem Beliakin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fighting Mildew With Robots | Earth Wise

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Cornell Researchers have partnered with Norwegian company SAGA Robotics to develop autonomous robots that can roam vineyards at night armed with ultraviolet lamps that can kill powdery mildew, which is a pathogen that devastates many crops, including grapes.

The robots are being field tested on Chardonnay grapes at two sites:  Cornell AgriTech’s research vineyards in Geneva, New York, and at Anthony Road Wine Co. in Penn Yan, New York.

Cornell has been researching the use of UV light to kill grapevine powdery mildew for nearly 30 years.  They have also worked with the University of Florida on using it to control powdery mildew in strawberries.

The UV treatment has been shown to suppress powdery mildew over a period of two years with the application of treatments once a week.  The technique represents a breakthrough because the mildew can adapt to chemical anti-fungal sprays in a single season, making them ineffective.  UV light damages DNA, but mildews have natural biochemical defenses that are triggered by the blue light present in sunlight.  By applying the UV at night, when there is no blue light from the sun, the defenses of the mildew are defeated.

In earlier trials, the researchers used UV lamps mounted on a tractor wagon, but this required all-night labor to treat an entire vineyard.  That has now been replaced with autonomous vehicles that can work seven nights a week, all night long.

The next development will be imaging technology that will detect and quantify mildew on grape leaves.  With this, the dose of UV light applied to a particular vine will depend on whether it is sick or healthy.

A high-tech solution to a problem that plagues vineyards.

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Robots armed with UV light fight grape mildew

Photo courtesy of Rodrigo Onofre/Twitter.

Earth Wise is a production of WAMC Northeast Public Radio.

PFAS In The Food Chain | Earth Wise

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Per- and polyfluoroalkyl substances (PFAS) are a family of human-made chemicals that have been manufactured and used in a variety of industries around the globe.  PFOA and PFOS have been the most extensively produced and the most extensively studied of these chemicals. 

Exposure to PFAS has been linked to a host of adverse health effects, including thyroid hormone disruption and cancer.

PFAS compounds can be found in such things as non-stick cookware, stain-resistant carpets, water-repellent outdoor gear, and food packaging, like fast food wrappers and microwave popcorn bags. 

According to a new study, researchers from North Carolina State University have found PFAS substances in every step of the Yadkin-Pee Dee River food chain, even though the river doesn’t have a known industrial input of these compounds. 

The team collected water, sediment, algae, plant, insect, fish, crayfish, and mollusk samples at five sites along the river and analyzed them for 14 different PFAS compounds.  Nearly every sample tested contained PFAS compounds.  Biofilm contained the largest concentrations of 10 of the 14 PFAS compounds measured.  Insects, which primarily eat biofilm, had the greatest accumulation of PFAS compounds of all the living taxa the researchers sampled. 

When PFAS compounds are present at every step of the food chain, the compounds accumulate at each step leading to greater concentrations in animals that sit higher on the food chain – including humans.  This is known as biomagnification. 

Studies like this that reveal how prevalent PFAS can be within ecosystems without an industrial input highlight the need for further research into how these compounds affect the environment and human health.

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PFAS present throughout the Yadkin-Pee Dee river food chain

Photo, posted May 24, 2011, courtesy of the U.S. Fish and Wildlife Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Making Use Of Invasive Seaweed | Earth Wise

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In recent years, millions of tons of brown Sargassum seaweed have formed gigantic blooms stretching all the way across the Atlantic Ocean from West Africa to the Gulf of Mexico.  The seaweed has become a problem for shorelines in the Caribbean, the Gulf of Mexico, and the east coast of Florida.  The massive increase in seaweed populations is related to changes in ocean chemistry resulting from nutrients from fertilizer use entering the water as well as from changes to the climate affecting ocean currents and temperatures.  The seaweed is harming the tourism industry as well as fisheries and ocean ecosystems.

Cleaning up the seaweed that washes ashore is labor-intensive and therefore expensive.  A research team led by two British universities has developed a cheap and simple way to pre-process seaweed to facilitate making it into bulk chemicals and biofuels.  With the new process, cleaning up the seaweed can be both economically and environmentally viable.

Previous techniques for processing seaweed generally required removing it from the saltwater, washing it in fresh water, and drying it – all of which add significant costs.  The new technique makes use of catalysts to release sugars from untreated seaweed that feed a yeast to produce a palm oil substitute.  At the same time, the process creates heat and pressure, turning the residual materials into a bio-oil that can be processed further into fuels, and a high-quality, low-cost fertilizer.

Apart from getting economic value out of the seaweed that is collected, any plastic collected alongside the seaweed can be converted to useful materials as well. 

It appears that the seaweed scourge is here to stay, so finding an economically viable way to deal with it is a welcome development.

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Solve invasive seaweed problem by turning it into biofuels and fertilisers

Photo, posted August 10, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Jet Fuel From Acetone | Earth Wise

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Acetone is a common organic solvent.  It is used to make plastic, fibers, drugs, and other chemicals.  It is commonly used by consumers as nail polish remover.  Acetone is a manufactured chemical, but it is also found naturally in the environment in plants, among other places. There are now companies that produce acetone entirely by fermentation of plant feedstocks, such as corn.

Researchers at Los Alamos National Laboratory have now developed a process by which acetone can be converted into a fuel additive that can improve the performance of petroleum-based jet fuel, providing both environmental and economic benefits.

The process takes biomass-derived acetone and converts it to isophorone, which they produce by a process called photochemical cycloaddition that creates more complex hydrocarbons.  They then use ultraviolet light to convert the isophorone into cyclobutane, which is a type of hydrocarbon with high energy density that is suitable for aviation fuel applications.

Acetone itself is quite volatile and is unsuitable for fuel applications.  It also cannot be added directly to any fuel supply since it can dissolve engine parts and o-rings.  Cyclobutane, on the other hand, is a safer and more energy-dense fuel that can be a replacement for additives that require high-pressure hydrogen treatment in their synthesis.  Currently, most hydrogen is produced by a process that generates carbon dioxide.  The new conversion process does not result in carbon emissions.

According to the Los Alamos researchers, their process can result in a domestically generated product that will provide environmental benefits, create domestic jobs, improve U.S. energy security, and further U.S. global leadership in bioenergy technologies.

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Acetone plus light creates a green jet fuel additive

Photo, posted December 18, 2007, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mealworms And Plastic | Earth Wise

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Mealworms are widely cultivated beetle larvae that people feed to pets and to wild birds.  But it turns out, they may have an even more valuable purpose:  they can eat plastic and even plastic containing dangerous chemical additives.

Four years ago, researchers at Stanford discovered that mealworms can actually subsist on a diet of various types of plastic.  They found that microorganisms in the worms’ guts actually biodegrade the plastic.  It might be possible to cultivate the worms using unrecyclable plastic, rather than feeding them grains and fruits.   However, there is the issue of whether it would be safe to feed the plastic-eating worms to other animals, given the possibility that harmful chemicals in plastic additives might accumulate in the worms over time.

Recently, the Stanford researchers studied what happens when the worms ingested Styrofoam or polystyrene.  The plastic commonly used for packaging and insulation typically contains a flame retardant called hexabromocyclododecane, or HBCD.  Studies have shown that HBCD can have significant health and environmental impacts, ranging from endocrine disruption to neurotoxicity.

According to the study, mealworms in the experiment excreted about half of the polystyrene they consumed as tiny, partially degraded fragments and the other half as carbon dioxide.  With it, they excreted the HBCD.  Mealworms fed a steady diet of HBCD-laden polystyrene were as healthy as those eating a normal diet.  And shrimp fed a steady diet of the HBCD-ingesting mealworms also had no ill effects.

It is true that the HBCD excreted by the worms still poses a hazard and must be dealt with in some manner, but mealworms may have a role to play in dealing with unrecyclable plastics like Styrofoam.

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Stanford researchers show that mealworms can safely consume toxic additive-containing plastic

Photo, posted May 11, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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