An aerial view of the Mississippi River-Lake Pepin watershed. Photo courtesy of the Minnesota Pollution Control Agency.
State health officials announced on Monday that some people should avoid eating fish caught in the Mississippi River from St. Paul to Hastings and from Lake Rebecca — a popular shore fishing lake near Hastings — after 16 types of toxic man made chemicals were found in fish populations.
But environmental scientists question whether health officials went far enough with their advisory in light of studies showing that even infrequent consumption can increase levels of the chemicals in human blood.
The chemicals, whose staying power in humans and the environment has earned them the nickname “forever chemicals,” are linked to a range of human health problems and were made by corporate giant 3M.
The Minnesota Department of Health said that children under 15; people who are or could become pregnant and people who are breastfeeding or plan to breastfeed should avoid eating fish from Lake Rebecca and that stretch of the river.
Dana Vanderbosch, assistant commissioner for water policy and agriculture for the Minnesota Pollution Control Agency, said the new guidance was prompted by a late June report by 3M that the department is still evaluating as part of a broader investigation.
The report found the fish had 16 types of per- and polyfluoroalkyl substances (PFAS), a family of chemicals that repel water and oil and remain stable under nearly all conditions.
Maplewood-based 3M has made the chemicals in Minnesota since the 1950s, and they’ve since become ubiquitous, used in a broad array of retail, industrial and technology products from microprocessors to non-stick pans. They’ve spread all over the planet, can be found in the blood of nearly all people and have been linked to low fertility, birth defects, suppression of the immune system, thyroid disease and various cancers. 3M has said it will stop making the chemicals and using them in products by the end of 2025.
Among the chemicals found in fish in the Mississippi River and Lake Rebecca was HQ115, a battery electrolyte that 3M produces and says is widely used as an additive to enhance battery performance. It has been detected in surface and waste waters in and around manufacturing facilities. The EPA recently published a toxicity assessment of the chemical, whose carcinogenicity has not been studied.
A standard doesn’t yet exist for most PFAS found in water and fish, but the number and level of chemicals found in Minnesota prompted the state to update its consumption guidance.
Sarah Fossen Johnson, a manager for the health department’s environmental surveillance and assessment section, said the “sheer number” of chemicals — some of which the department has little to no toxicological data on — is concerning.
“We were quite surprised by what we saw in the data so we felt it was more important to help people reduce their exposures now, while we continue to examine the data that we do have,” she said.
Asked why the state waited until now to alert the public if officials have known since June, Fossen Johnson said officials needed time to review the data and consider a variety of factors, including the health benefits of eating fish. She said the type of PFAS seen in fish generally don’t present immediate health threats, so people won’t get sick from eating a few fish over time. But health officials thought it was important to alert people in “sensitive life stages” so they could begin reducing their exposure.
MDH Assistant Commissioner Dan Huff said the advisory only applies to higher-risk people and is based on long-term exposure, “not the kind of short-term exposure you might have from a few meals.”
Huff said fish are a source of low-fat protein, and the omega-3 fatty acids found in fish may promote heart and overall health, but there can be risks associated with eating certain amounts of fish from some lakes and waterways.
A study by the Environmental Working Group found consuming just a single serving of freshwater fish per year could be equal to a month of drinking water laced with a forever chemical called PFOS at high levels that may be harmful.
3M recently negotiated a $10.3 billion settlement over contaminated U.S. drinking water systems with chemicals it made.
A scientist with the Green Science Policy Institute, Ariana Spentzos, is not part of any of the high-risk groups, but said, “Personally, I wouldn’t eat those fish.”
“That would definitely give me pause,” she said.
She’s also surprised it took the department so long to warn the public.
“One would hope that it would certainly be a lot faster than that,” Spentzos said.
Tasha Stoiber, senior scientist with the Environmental Working Group, said the level of PFAS in fish are “quite high” in that area of the Mississippi River, according to its map of water pollution in streams and rivers nationwide.
Anyone that consumes freshwater fish — especially those with higher levels of PFAS — can be impacted by just one or two meals, Stoiber said.
“This is quite a concern for everyone,” she said. State health officials previously recommended not eating certain types of fish in the lake and river due to PCBs and mercury, which have been detected in fish in Minnesota for decades.
DNR Regional Fisheries Manager Brian Nerbonne said people can still fish at Lake Rebecca and the river if they catch and release the fish.
This year, the Legislature passed what some have called the nation’s broadest limits on the chemicals, banning them from 13 products beginning in 2025, and all products in 2032. The new law requires manufacturers to disclose if the chemicals are in their products beginning in 2026. The Legislature also approved funding for more toxicologists and monitoring and research of the chemicals.
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