Cleaning up PFAS

Scrubbing Earth of per- and polyfluoroalkyl substances—a.k.a. PFAS or forever chemicals—could eliminate a list of woes for people and planet. Used for decades in everything from nonstick pans to firefighting foams, PFAS have been linked to increased risks offertilitychallenges,developmental delays,cancer, andreduced immune response. They are known for a strong bond between carbon and fluorine, which the environment struggles to break down. PFAS are everywhere: They spew from factories and slough off products and into water with normal use. Scientists have found them in everything fromhuman bloodtoAntarctic snow. One2022 reportfound that 89% of the US population had PFAS in excess of two nanograms per milliliter of blood plasma, a common threshold for potential adverse health effects, and 9% of the population had passed the riskier level of 20 nanograms per milliliter. The PFAS monster is also a moving target. New compounds are still being created and used. There are more than 12,000 of them, and much of the cleanup research focuses on only a small handful. Cleansing PFAS-contaminated soil is a project in its infancy, but it is possible to prevent more buildup by pulling the chemicals out of water systems. There are two ways to handle this: trap or destroy. Some scientists have found reverse osmosis—a process that pushes water through supertight filters—useful inpoint-of-use cases, like water filters at kitchen sinks. Other techniques in the pipeline might be more suitable for large-scale removal—for example, at water treatment facilities. One, calledfoam fractionation, generates bubbles that capture PFAS. More approaches, like ensnaring the chemicals in nanothin layers of charged metal, are also under investigation. Trapping, though, is imperfect. You’re left with PFAS-filled brine, which if not properly destroyed (an expensive and energy-sucking endeavor) can still end up in the environment. Jack Huang, a professor of crop and soil sciences at the University of Georgia, is working on destruction. He’s testing a method calledelectrochemical degradation, which uses electrodes to break down the bonds that hold PFAS together. The product destroyed more than 90% of PFAS mass in tests and has already beenlicensed by the engineering consulting firm AECOM. Ridding life of PFAS is also a policy challenge. There are alternatives; we just need the push to use them. And we’ve had success before: The EPA’s2010/2015 PFOA Stewardship Programhas helped slash the release of water-repellent perfluorooctanoic acid by 95%. More recently, Minnesota, Maine, and New Mexico have passed bans on PFAS in products like cookware and dental floss. Scientists are making strides toward removing and destroying PFAS—but it’ll be all for naught if we don’t turn off the tap. Huge grid-scale batteries are thriving, but smaller residential systems have lagged. Startup Switch Bioworks hopes to use microbes to reduce demand for chemical fertilizer. Discover special offers, top stories, upcoming events, and more.