New guidance on fish consumption points to contaminated ecosystems

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Matt Doll, Minnesota Environmental Partnership

Last week, the Minnesota Department of Health released new guidance on fish consumption in Minnesota that indicate an emerging harm present in our ecosystem. It’s a sign that longstanding threats like mercury – while still dangerous – aren’t the only toxins accumulating in Minnesota food chains. The newer villain PFOS has made its way into our dinner tables.

The new guidance affects the panfish category – the crappies, sunfish, and trout. These fish are frequently caught by Minnesota anglers, especially in the southern half of the state. They’re also less likely to have elevated mercury levels than fish like walleye, bass, and northern pike.

Previous guidance recommended that people who are above the age of 15 and will not become pregnant could eat as many servings of panfish as they want in a week. The new guidance sets the number of servings per week at only four. For context, a serving of fish is equivalent to about six ounces cooked for a person who weighs about 150 lbs.

The guidance is changing because the pollutants in our environment are changing. Previously, the Department of Health only considered two pollutants in its recommendation. Mercury, with its tendency to bioaccumulate in fish in ways that are especially dangerous to humans, is one of them. Mercury pollution levels have decreased over the decades in Minnesota, but it continues to end up in Minnesota fish due to interstate coal plant emissions and mercury methylation. (Check out the MEP-commissioned report, Mercury in the St. Louis River Watershed.) The other is polychlorinated biphenyl, or PCB, a toxic “forever chemical” that has been banned in the United States since the 1970s. PCB continues to cause health problems, and it is estimated that more than 300,000 tons of it are present

The Department is now including Perfluorooctanesulfonic acid, or PFOS (brownie points if you can pronounce the full name) in determining how much panfish is safe, and the tightened number is another sign that this harmful chemical is spreading through our environment. PFOS is (perhaps confusingly) a category of PFAS appearing in the news more and more due to contamination issues from these forever chemicals.

PFOS is best known for being an ingredient in Scotchguard – a 3M-made stain protector chemical – as well as its use in industry. It’s a particularly ubiquitous and persistent chemical, estimated to be found inside the bodies of almost every person in the United States, though fortunately, concentrations are believed to be decreasing over time. Studies have indicated that PFOS can be a factor in kidney disease, immune conditions, cancers, and ADHD for those who have higher blood levels.

The chemical was largely voluntarily phased out of U.S.-made products years ago, but with an asterisk: it’s still making its way into the country via imports. The more PFOS products that are sold and disposed of, the more it will continue making its way into the food chain. Canada, on the other hand, has a ban on imports containing PFOS in addition to banning domestic production.

PFOS isn’t going away any time soon, and it certainly won’t be breaking down in our lifetimes, if ever. We can’t predict now whether future technology will help alleviate this problem, but we do know that the continued industrial use of PFOS will make the problem worse, impacting fish in Minnesota and around the world. Now would be a great time for state and federal governments to step up and take strong measures against this and other forever chemicals, so that Minnesotans can eat fish with peace of mind.

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