A class of man-made chemicals that are toxic even in minuscule concentrations, for decades PFAS were used to make products like nonstick pans, stain-resistant carpeting and firefighting foam. The substances have come under scrutiny in recent years for their tendency to persist in the environment, and to accumulate inside the human body, as well as for their links to health problems like cancer and birth defects. Both Congress and the Biden administration have moved to better regulate PFAS, which contaminate the drinking water of as many as 80 million Americans.Industry researchers have long been aware of their toxicity. But it …
