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Tracking down PFAS toxins

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PFAS – per- and polyfluoralkyl substances – are a group of organic compounds that have been extensively used to provide water-, oil-, and dirt-resistance to a wide range of products ranging from non-stick pans, clothing, and packaging to paint, car polish, and fire-suppressant foam.  Exposure to specific PFAS compounds is associated with multiple adverse health effects, including altered immune and thyroid function, liver disease, kidney disease, poor reproductive and developmental outcomes, and cancer.  PFAS compounds do not break down in the environment and therefore, over time, become concentrated in plants, animals, and people.

Government agencies such as the EPA in this country and the EU have set strict limits for allowable levels of PFAS in drinking water.  Testing water for the trace amounts of PFAS that constitute the limits is time-consuming and expensive and requires complex equipment and experienced personnel.

Researchers at MIT have now introduced a technique for making a portable, inexpensive test that can easily and selectively detect PFAS in water samples.  The test makes use of a special polymer containing fluorinated dye molecules that cause the polymer to fluoresce red.  If PFAS are present in the sample, they enter the polymer and displace the dye molecules and switches off the red fluorescence. 

The new technique is suitable for on-site detection in highly contaminated regions.  Detecting smaller concentrations can be achieved with sufficient precision after pre-concentrating the samples using the process of solid-phase extraction.

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Tracking down Environmental Toxins

Photo, posted October 16, 2021, courtesy of Nenad Stojkovic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Destroying Forever Chemicals | Earth Wise

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PFAS, short for poly and perfluoroalkyl substances, have been used in commercial products since the 1940s.  There are more than 4,000 different chemicals in the class.   Some of the most commonly used PFAS chemicals, like PFOS and PFOA, have long half-lives, which has earned them the moniker “forever chemicals.” 

These dangerous chemicals have not been manufactured in the U.S. since the early 2000s, but they can still be found in various imported goods.  PFAS chemicals have been linked to cancer, birth defects, thyroid disease, and liver damage.  These forever chemicals linger in the environment and scientists have found them in the blood of virtually all Americans.

Researchers at Rice University have recently discovered an efficient catalyst for destroying PFAS forever chemicals.  Unexpectedly, the catalyst was actually in the control group in a study they were performing.

The study, published in the journal Environmental Science and Technology Letters, found that boron nitride, acting as a light-activated catalyst, destroyed PFOA at a faster clip than any previously reported photocatalyst.

The catalyst, boron nitride powder, is a commercially available synthetic mineral that is widely used in makeup, skincare products, thermal pastes for cooling computer chips, and various other industrial products.  The discovery began with dozens of failed experiments on a variety of more promising PFAS catalysts.  But along the way, they found that the boron nitride control material repeatedly yielded positive results.

The research has already attracted the attention of industrial partners seeking to develop off-grid water treatment systems that both protect human lives and support sustainable economic development.

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Boron nitride destroys PFAS ‘forever’ chemicals PFOA, GenX

Photo, posted April 9, 2009, courtesy of Rex Roof via Flickr.

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.

WAMC Northeast Public Radio

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