The Department of Natural Resources issued a consumption advisory Friday for rainbow smelt from Lake Superior after elevated levels of PFAS were found in the fish.
The DNR, along with the Department of Health Services, is recommending that rainbow smelt from the lake only be consumed once a month, after samples showed elevated levels of PFOS, according to a release. If consumed more than once a month, the risk of health problems increases.
PFAS, or per- and polyfluoroalkyl substances, are a family of man-made chemicals used for their water- and stain-resistant qualities in products like clothing and carpet, nonstick cookware, packaging and firefighting foam. The family includes 5,000 compounds, which are persistent, remaining both in the environment and human body over time. PFOS (perfluorooctane sulfonate) is one of the most well-researched in the family of compounds.
PFAS have been linked to types of kidney and testicular cancers, lower birth weights, harm to immune and reproductive systems and altered hormone regulation and thyroid hormones.
Rainbow smelt are small, silver fish that are not native to Lake Superior, but can be found there, according to the department. Sometimes the fish can be caught during ice fishing season, but the majority of smelt are captured in the spring as the fish migrate to the nearshore to spawn. The fish are commonly consumed during fish fries in the spring months.
No other PFAS-based consumption advisories for other fish species in the Great Lakes have been issued, the release said. The DNR also received and tested samples of results from bloater chub, cisco/lake herring, lake whitefish, lake trout, and siscowet lake trout in Lake Superior and crappie, yellow perch, channel catfish, carp, northern pike, walleye, and musky from the St. Louis River. No elevated levels of PFAS were found in those fish.
PFAS have made their way into water sources in a variety of ways, including the discharge of firefighting foam containing the chemicals and the release of wastewater to treatment plants, the release said.
Rainbow smelt are not the first animals to have consumption advisories due to PFAS contamination. In Marinette, the chemicals were found in the tissue of fish harvested near the Tyco Fire Products facility, prompting more testing. The chemicals were also found in the livers of deer near the same facility last year, prompting a consumption warning before deer season last year.
Laura Schulte can be reached at firstname.lastname@example.org and on Twitter at @SchulteLaura.