Removing PFAS from public water will cost billions and take time – here are ways to filter out some harmful ‘forever chemicals’ at home

PFAS are showing up in water systems across the U.S. Jacek Dylag/Unsplash, CC BY by Kyle Doudrick, University of Notre Dame Chemists invented PFAS in the 1930s to make life easier: Nonstick pans, waterproof clothing, grease-resistant food packaging and stain-resistant carpet were all made possible by PFAS. But in recent years, the growing number of health risks found to be connected to these chemicals has become increasingly alarming. PFAS – perfluoroalkyl and polyfluoroalkyl substances – are now either suspected or known to contribute to thyroid disease, elevated cholesterol, liver damage and cancer, among other health issues. They can be found in the blood of most Americans and in many drinking water systems, which is why the Environmental Protection Agency in April 2024 finalized the first enforceable federal limits for six types of PFAS in drinking water systems. The limits – between 4 and 10 parts per trillion for PFOS, PFOA, PFHxS, PFNA and GenX – are less than a drop of water in a thousand Olympic-sized swimming pools, which speaks to the chemicals’ toxicity. The sixth type, PFBS, is regulated as a mixture using what’s known as a hazard index. Meeting these new limits won’t be easy or cheap. And...