https://www.theguardian.com/environment/article/2024/may/18/pfas-great-lakes-basin

Toxic PFAS “forever chemicals” are ubiquitous in the Great Lakes basin’s air, rain, atmosphere and water, new peer-reviewed research shows.

The first-of-its-kind, comprehensive picture of PFAS levels for the basin, which holds nearly 95% of the nation’s freshwater, also reveals that precipitation is probably a major contributor to the lakes’ contamination.