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Smelt consumption advisory issued for Lake Superior

Based on recent sampling results, the Wisconsin DNR and the Department of Health Services (DHS), are recommending a PFAS-based fish (per and polyfluoroalkyl substances) consumption advisory for Lake Superior.

Because of the high levels of PFOS found in the samples, the departments are updating the recommended rainbow smelt consumption advisory from an unrestricted amount, to one meal per month for Lake Superior.

The sampling completed by the DNR, found elevated levels of PFAS, particularly the compound PFOS, in rainbow smelt in Lake Superior. PFAS are a group of over 5,000 human- made chemicals, used for decades in numerous products, including non-stick cookware, fast food wrappers and stain-resistant sprays.

These legacy contaminants have made their way into the environment in a variety of ways, including spills of PFAScontaining materials, discharges of PFAS-containing wastewater to treatment plants and certain types of firefighting foams.

The risk of health problems increases with the amount of contaminated fish eaten. Following this advisory will help protect consumers from excess PFAS exposure found in fish. The advisory could change in the future, as the DNR and DHS continue to learn more about the health risks from eating fish caught from the area, and more fish data become available.

As part of the DNR’s statewide PFAS monitoring efforts to monitor fish tissue and water chemistry at select sites around the state, smelt were collected from two locations in Lake Superior in 2019, approximately 30 miles apart, at sites near the Apostle Islands and off Port Wing. PFAS was detected in samples from both locations.

Rainbow smelt are a small, silver fish, that are non-native to Lake Superior. Some anglers will catch smelt through the ice, but the majority of smelt harvest occurs in the springtime, as the fish migrate into nearshore areas to spawn.

Some health risks associated with PFOS, one of the thousands of PFAS compounds, include lower birth weight, possible links to increased risk of kidney and testicular cancer, harm to the immune and reproductive systems, increased cholesterol levels, and altered hormone regulation and thyroid hormones.