PFAS — so-called “forever chemicals” — are everywhere. So much so that you or someone (or someones) you love are probably already carrying toxic levels of the chemicals, and will likely have some adverse health effects because of that contamination. (It’s not even clear how much of an exposure means you increase levels of, for example, certain cancers or endocrine disruption diseases.)
An estimated 26,000 U.S. sites are contaminated with some form of PFAS. At least six million Americans are estimated to have drinking water containing some form of PFAS above the existing safe limits recommended by the U.S. EPA.
Coming up with ways rid of these PFAS chemicals from our environment has been difficult because the properties that make them so durable in everyday use are the same ones that make them tough to destroy.
For over a century, our world has been made of plastic. It’s in everything from firefighting foam to water bottles to nonstick pans, yielding convenient products that last. But in the long run, plastic releases hazardous chemicals, called Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS), that seep into the soil and groundwater. These “forever chemicals” are everywhere today: in our drinking supplies, our food, the air, and even our bodies, where they can lead to unwelcome consequences, including cancer, infant development problems, and weakened immunity.
Scientists have been working on ways to destroy PFAS chemicals that permeate our environment, but no easy method exists. That’s because these standoffish compounds don’t react to anything—not biological or other chemical agents. They stick only to each other and resist being torn apart. Current methods require“very harsh conditions to decompose these compounds,” according to chemists at Northwestern University in Evanston, Illinois. Until now, how to break those PFAS bonds has been unclear.
That team’s recent work, published in the journal Science on August 18, proves that the stubborn power of PFAS bonds can, in fact, be broken. The scientists discovered a way to disintegrate two concentrated, toxic forms of PFAS into smaller, innocuous compounds that decompose. Using low heat, a solvent, and sodium hydroxide (lye, the basis of some soaps), the method is both simple and inexpensive. It works for two major categories of PFAS permeating the environment today: perfluorooctanoic acid (PFOA) and one of its common replacements, known as GenX.
The traditional difficulty in destroying a PFAS compound lies in its many carbon-fluorine bonds, which organic chemists know as the strongest bonds. They require immense heat (about 400 degrees Celsius) and pressure to break, which can lead to cases of air contamination during incineration, William Dichtel, the lead author of the new study, explains in a news release. “In New York state, a plant claiming to incinerate PFAS was found to be releasing some of these compounds into the air,” says Dichtel, a professor of chemistry. “The compounds were emitted from the smokestacks and into the local community.” And burying PFAS just causes them to contaminate the environment after a few decades, he adds.
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