There is finally some good news about toxic PFAS ‘forever chemicals’. Scientists have just discovered a way to break down, or destroy, at least two PFAS chemicals (there are over 12,000 PFAS chemical compounds in existence).
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The “forever” part of ‘Forever Chemicals’
PFAS, a group of manufactured chemicals commonly used since the 1940s, are called “forever chemicals” for a reason: Quite simply, there has been no known way to break these chemicals down. “Bacteria can’t eat them; fire can’t incinerate them; and water can’t dilute them. And, if these toxic chemicals are buried, they leach into surrounding soil, becoming a persistent problem for generations to come.” From a science perspective, PFAS chemicals have biological half-lives that are still unknown. Up until now, scientists have believed that because the chemicals do not break down in the environment or human/animal bodies (thus the nickname “forever” chemicals) and because the chemicals have not responded to previous scientific efforts to destroy them, they would be around forever.
“The secret to PFAS’s indestructibility lies in its chemical bonds. PFAS contains many carbon-fluorine bonds, which are the strongest bonds in organic chemistry. As the most electro-negative element in the periodic table, fluorine wants electrons — and badly. Carbon, on the other hand, is more willing to give up its electrons.” (source)
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Why PFAS are chemicals of concern
The family of PFAS chemicals (per- and polyfluoroalkyl substance) are known endocrine-disrupting chemicals and toxic to humans; they are ubiquitous in the U.S., appearing in drinking water and in every manner of products. PFOS (perfluooctane sulfate) and PFOA are two types of PFAS chemicals that can be found in food packaging and plastic water bottles (where it can leach into the food you eat and drink), and numerous consumer products including cookware/bake ware/cooking utensils, stain-resistant and waterproof furniture, clothing and carpet, household products, personal care products, cosmetics, and more.
At this point, PFAS chemicals have made their way out of consumer goods and into our drinking water and into the blood of 97% of the U.S. population. PFAS chemicals have been shown in scientific studies to adversely affect the immune system and hormonal system and have been linked with a wide range of serious health outcomes, including immune system problems, hormonal problems, developmental problems, high cholesterol and even cancer. Additionally, because PFAS chemicals disrupt the metabolism of a person’s liver, people exposed to high levels of PFAS chemicals are also at risk of developing non-alcoholic fatty liver disease (NAFLD) and even liver cancer.
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The new discovery
Though a bit more complex than this, in laypersons’ terms:
“Using low temperatures and inexpensive, common reagents, the research team developed a process that causes two major classes of PFAS compounds to fall apart, including commonly used PFOA (perfluorooctanoic acid) and one of its common replacements, known as GenX, two of the most prominent PFAS compounds, leaving behind only benign end-products.
The simple technique potentially could be a powerful solution for finally disposing of these harmful chemicals, which are linked to many dangerous health effects in humans, animals and the environment.” (source |source)
While studying the compounds, the researchers found a weakness: PFAS contains a long tail of unyielding carbon-fluorine bonds. But at one end of the molecule, there is a charged group that often contains charged oxygen atoms. The scientific team targeted this head group by heating the PFAS in dimethyl sulfoxide (an unusual solvent for PFAS destruction) along with with sodium hydroxide, a common reagent*. The process decapitated the head group, leaving behind a reactive tail. (source |source)
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*Other researchers have used high temperatures — up to 400 degrees Celsius–to try and break down PFAS chemicals. But the new technique relies on milder conditions and a simple, inexpensive reagent, making the solution potentially more practical for widespread use.
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What’s next
“Our work addressed one of the largest classes of PFAS, including many we are most concerned about. There are other classes that don’t have the same Achilles’ heel, but each one will have its own weakness. If we can identify it, then we know how to activate it to destroy it.” (source)
-Dr. William Dichtel, chemist
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You may also be interested in this: UW researchers develop a reactor that can destroy ‘forever chemicals’
Journal reference: Trang, B., et al. Low-temperature mineralization of perfluorocarboxylic acids, Science, 18 Aug 2022, Vol 377, Issue 6608, pp. 839-845. DOI: 10.1126/science.abm8868
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