PFAS, or per- and polyfluoroalkyl substances, are a class of about 12,000 chemicals often used to make products resist water, stain and heat. They are called “forever chemicals” because they don’t naturally break down, and are linked to cancer, liver problems, thyroid issues, birth defects, kidney disease, decreased immunity and other serious health problems.
Previous analyses have used municipal utility data to estimate that the chemicals are contaminating drinking water for over 200 million people, while another study found widespread contamination of groundwater drawn by private and municipal wells.
Lax regulation allows industrial users to discharge the chemicals into the environment largely unchecked, though some states and the US Environmental Protection Agency (EPA) are taking steps to begin tracking them. Landfills, airports, military bases, paper mills and wastewater treatment plants are among common