A class of toxic chemicals known as PFAS has made its way into food, soil, water and even most people's blood in America. In March, the EPA proposed the first regulatory standard limiting the quantity of PFAS in drinking water. Erin Bell, an environmental epidemiologist at the State University of New York at Albany, joins Ali Rogin to discuss these "forever chemicals" and our exposure to them. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders