'Forever chemicals' entering Great Lakes through precipitation and air: Study

Toxic "forever chemicals" are entering the Great Lakes through both precipitation and the air — reaching cities of all sizes along the U.S. and Canadian shores, a new study has found.

Levels of the compounds — per- and polyfluoroalkyl substances (PFAS) — remain uniform in precipitation across the lakes but vary in the air depending on the location, according to the study, published on Thursday in Environmental Science & Technology.

“The levels in precipitation don’t depend on the population," first author Chunjie Xia...