Did PFAS contamination cause a consumption advisory for fish in Lake Superior?
The Wisconsin Department of Natural Resources and the Department of Health Services advised people to eat no more than one meal a month of rainbow smelt from Lake Superior in January 2021. The advisory followed the discovery of high levels of per- and polyfluoroalkyl substances, persistent contaminants known as "forever chemicals."
Michigan's health department issued a similar warning in 2022.
PFAS are manmade chemicals that have been used in numerous industrial and consumer products for decades, including firefighting foam, which was used on a series of fires at a Superior oil refinery in 2018, causing elevated levels of PFAS in a creek that flows into Lake Superior.
In early 2020, samples for perfluorooctane sulfonate — the specific substance of concern detected in rainbow smelt — continued to average around 40 times higher than normal in the creek.
The substance has been linked to illnesses including cancer, fertility issues and developmental problems.