Almost half the tap water in the United States contains PFAS, also called forever chemicals. This class of compounds never fully break down in nature and have been linked to serious health problems. 

In April the Environmental Protection Agency required the removal of PFAS from drinking water. Now industry is pushing back. This week a group of chemical and manufacturing companies sued the EPA, saying it overstepped its authority. 

ProPublica’s Sharon Lerner has been reporting on these substances for years. Her latest piece appears in The New Yorker and is titled “How 3M Discovered, then Concealed, the Dangers of Forever Chemicals.” 

Lerner joins Diane on this episode of On My Mind to talk about the history of PFAS and how they became so ubiquitous.