Minnesota’s poisoned fish
Fish from a PFAS-contaminated lake is sold out of state. Caveat emptor - Let the buyer beware
The state allows pregnant women to consume high amounts of PFAS in fish
By Pat Elder
December 5, 2021
Invasive carp present a growing threat to Minnesota’s environment. - Friends of the Mississippi River
Invasive carp cause serious damage to native fish populations in the Mississippi River and the lakes and rivers throughout the Midwest because they out-compete native species for food and space. The fish are wild and thrash about as they sail through the air, sometimes smacking fishers in the face. The carp pose another more serious threat, however.
A crew of fishermen extracted more than 26,000 pounds of the carp from Lake Winona in Alexandria, Minnesota last month. The fish are on their way to be sold to fish markets on the east coast. It sounds like a good plan, except that the fish are likely to be contaminated with Perfluoro-octane sulfonic acid (PFOS), a particularly dangerous kind of PFAS. Three weeks after the fish were removed, the Minnesota Pollution Control Agency announced it had found high concentrations of PFOS in fish from the lake.
A fish broker (yes, there is such a thing), who was arranging for the sale of the carp said he operated “on the assumption that Minnesota and Wisconsin lakes are safe. Mercury is what we think of. ... This PFOS issue is a really new thing.”
Not really. Minnesota has been testing the state’s waters and fish for PFAS since 2004. The state has identified 26 water bodies that are impaired due to PFOS. That number is likely to be much higher in this land of 10,000 lakes.
Increasingly, states and fish brokers are turning to a kind of “If you can’t beat ‘em - eat ‘em” solution. Nationally, the invasive carp is being re-branded and sold as frozen fish cakes in a growing number of markets.
PFOS was detected in Sunfish in Lake Winona this summer and the state’s Department of Health issued a fish consumption advisory. Minnesota is now recommending that its residents eat no more than one meal per week of sunfish taken from Lake Winona. We don’t know the levels of contamination found. One meal may be too much.
If the carp are deemed to be unfit for human consumption, they shouldn’t be fed to our pets, turned into fertilizer, or sent to landfills - but no one is checking.
Jim Kelly, who manages the Minnesota Department of Health programs that include the fish consumption advisory, told Echopress it was difficult without further testing to determine whether people should limit their consumption of carp from Lake Winona. As it is being sold in other states, he said that will likely be up to the health departments in those states.
Not good.
Minnesota must get to work testing fish for PFOS and it must publish results. All states ought to be testing fish for human consumption.
Michigan released test data last year showing concentrations of PFOS in fish including carp in various waterbodies, although we don’t know the exact species. The data included sampling results on 121 carp. The average carp contained 19,047 ppt of PFOS while the median range was 15,875.
Chop it up. Get the bones out of it. Cut it into fish cakes. Freeze it and sell it?
The entire nation is dealing with PFAS-contaminated fish - each state on its own terms. Officials in Vermont reacted to the news this week that fish contained 15,000 ppt of PFOS in the Winooski River by claiming that figure “is within the range of "typical background concentrations" for PFOS in fish tissue. It’s chilling.
Women of Child-bearing age and their babies are most vulnerable
Let’s examine Minnesota’s Fish Advisories for Pregnant Women, Women who could become pregnant, and Children under age 15. The state directs this group to first check Statewide Safe-Eating Guidelines, seen here:
Source: Minnesota Dept. of Health
Women of child-bearing age are directed to check the three sets of Waterbody Specific Safe-Eating Guidelines for lakes, rivers, and Lake Superior to see if there are more restrictive guidelines for fish species they may catch and consume in these waterbodies. Minnesota’s 2021 PFAS Blueprint says the Fish Contaminant Monitoring Program “has monitored for PFAS in fish from 178 lakes and 12 rivers, but does not include PFAS as part of routine analysis of fish collected in the monitoring program.
The Fish Consumption Guidelines for Pregnant Women, Women Who Could Become Pregnant, and Children under Age 15 for rivers in the state covers one small segment of the Mississippi River:
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Ford Dam to Hastings Dam, Pool 2
Do Not Eat Carp - all sizes
1 meal / month Sunfish - all sizes
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The Mississippi flows 650 miles through Minnesota and a lot of it is contaminated with PFOS. The stretch described above is about 30 miles long. Wabasha is 60 miles south of this protected area. The EPA reported finding a Sauger fish in the Mississippi in Wabasha containing 237,000 ppt of PFOS. Winona, 30 miles south of Wabasha, recorded a white bass with 163,000 ppt. A white crappie caught nearby contained 86,200 ppt of PFOS. See the Minnesota fish data here - and special thanks to Teresa Gerade of Newport Vermont for her help. The Minnesota Pollution Control Agency certainly is aware of these findings by the EPA but allows the most vulnerable elements of the population to be exposed to these chemicals.
The fish are poisoned.
The EPA collected fish from 30 different sites on the Ohio, Missouri, and Upper Mississippi Rivers (10 sites for each river.) Values reported by the EPA shown above for PFOS in fish are in parts per billion. The results are shocking, especially considering the Food and Drug Administration’s recent manifesto that Americans should not exclude specific foods from their diet because of concerns about PFOS contamination:
FDA: “There is no scientific evidence that supports
avoiding particular foods in the general food supply because
of concerns regarding PFAS contamination.”
The Minnesota fish contain tens of thousands of parts per trillion of PFOS. The state looks the other way while it limits PFOS in drinking water to 15 parts per trillion. Generally, the other states on the map aren’t any better at protecting public health.
Minnesota says it OK for pregnant women to eat any fish in Lake Superior at least once a month. Some fish, like Brown Trout and Chinook Salmon may be eaten four times a month and it’s OK to eat Pink Salmon 16 times a month. Are they sure about this? They say Lake Whitefish may be consumed 8 times a month when the data shows 31,270 in this species in Lake Superior. This is not sound public policy. A Brown Trout was found with concentrations of 35,000 ppt for PFOS. Pregnant women should not be eating this 4 times a month. (See the Lake Superior fish data.)
Negotiating the Minnesota Pollution Control Agency site is pretty tough. It ought to be as simple as typing in the name of the lake you’re concerned with and pulling up water quality and fish data pertaining to PFAS, along with clearly stated advisories. It’s not like that. I asked the MPCA for fish data but they did not respond. How bad is it, Minnesota?
I traded a few emails with Cori Rude-Young of the Minnesota Pollution Control Agency, (MPCA). I shared a prior draft of this article with her and others in the agency. She responded: “I had a couple of staff take a look at the draft blog. The draft includes many inaccuracies and misunderstandings of the science and policy surrounding PFAS. We recommend not equating guidance values for pollutants across different media types as exposure to media differs, not making assumptions about environmental justice regions (see MPCA’s EJ mapping ), taking time to understand the differences between statewide and site-specific fish consumption advice for waterbodies (see MDH website, including recent updates), and reviewing the most recent toxicity assessment for PFOS.”
Ouch! Let’s pick it apart. “MPCA recommends not equating guidance values for pollutants across different media types as exposure to media differs.”
There is an apparent contradiction in the MPCA response to the draft article. The agency provides information on their website that states, “Concentrations of PFOS can be more than 7,000 times higher in fish tissue than the surrounding water, so where a waterbody is used for harvesting fish and as a source of drinking water, eating fish can be a larger source of exposure because the PFOS concentrates so highly in fish tissue.”
It is true that care must be taken when correlating a chemical between environmental media types, but for a bioaccumulative chemical like PFOS, it is essential to derive ambient water quality values based on the human consumption of fish, particularly when the waterbody is used as a drinking water source.
Denise Trabbic-Pointer, a former Dupont chemist working with the Sierra Club’s Michigan Chapter explained, “We can learn from history here, by looking at how EPA and other state agencies set drinking water maximum contaminant levels (MCL’s) for Polychlorinated Biphenyl (PCB). PCB are known for their propensity to bioaccumulate and concentrate in the fat of fish and other wildlife. For this reason and because of the physical properties of PCB and how it acts in water, the best way to assess appropriate water quality values and drinking water standards, was to use bioaccumulation and bioconcentration factors to derive the PCB Maximum Contaminant Level of 0.0005 mg/L.”
Trabbic-Pointer continued, “Certain PFAS are highly bioaccumulative in aquatic organisms such as fish, and this is especially true for long-chain PFAS such as PFOS. According to the Interstate Technology Regulatory Counsel (ITRC), “Regulatory agencies use relevant and appropriate use-specific exposure factors combined with chemical-specific toxicity factors (reference doses; cancer slope factors) to develop ambient water quality criteria (AWQC) that are protective of human health for these uses and exposure pathways. The exposure pathways usually considered in development of AWQC are drinking water ingestion (for waters designated for drinking water use) and consumption of aquatic organisms.” The fact that, as MPCA has told us, the concentration in aquatic life of PFOS is 7,000 times higher than in the surface water due to PFOS bioaccumulative nature, makes it imperative to assess safe levels of PFOS in surface and drinking water. In other words, it is not just scientifically and technically acceptable to equate guidance values across different environmental media types, it is essential to do so in order to derive safe, health-based guidance values.” Thank you, Denise.
MPCA says I shouldn’t be making assumptions about environmental justice (EJ) regions and they directed me to see MPCA’s EJ mapping tool. It’s an excellent resource, although the mapping confirmed my finding that the most stringent fish and water quality standards were not located in EJ communities. Instead, the more protected waters include several bodies east of the Twin Cities metro area where the chemicals — used by Maplewood-based 3M to make various products - entered the area’s groundwater after decades of dumping into landfills. These areas are generally more affluent than the rest of the state.
MPCA said I ought to take the time to understand the differences between statewide and site-specific fish consumption advice for waterbodies (see MDH website, including recent updates). The webpage they pointed me to says in bold: Put Fish on Your Plate - Eating fish is good for you. Overall, the website is too complicated. Anyone with an excellent middle school education ought to be able to obtain the information they need quickly and easily. Not so here: https://www.health.state.mn.us/communities/environment/fish/#statewide
Lastly, the MPCA suggested I review the most recent toxicity assessment for PFOS, which includes formulas like this:
I looked at the toxicity assessment but I didn’t understand all of it, like the equation above. (Vd?) I can ask my friends with the Sierra Club, the Environmental Working Group, Harvard’s School of Public Health and Northeastern University if I really need to understand it.
This much I understand:
The state’s advisory for PFOS consumption in fish fails to protect public health.
https://www.pca.state.mn.us/sites/default/files/p-gen1-22.pdf
If there are no other more restrictive measures specific to a body of water and/or species, the guidelines above are followed. It’s OK to eat one fish a week with concentrations up to 50,000 ppt of PFOS.
The Fish Consumption Guidelines for lakes, rivers and Lake Superior only cover a small percent of all of the water bodies in the state and many of the PFOS warnings only apply to one or two species of fish, like the sunfish from Lake Winona. There’s a lot of work to be done ascertaining the threat posed to public health from PFOS-contaminated fish.
Ingesting PFOS in tiny amounts is clearly associated with endocrine disruption, obesity, reproductive disorders, breast cancer, liver disease, kidney disease, asthma, and immunotoxicity. The European Food Safety Authority says the vast majority of PFOS in our bodies comes from the food we eat, especially fish taken from contaminated water.
The chemical crosses the placenta. PFOS exposure during gestation results in impaired growth and metabolic disruption. Exposures to PFOS in utero have been associated with reduced antibody response to vaccinations in children and increased obesity.
The Minnesota Pollution Control Agency has established responsible PFOS values for fish tissue and surface water in a few selected waterbodies:
Lake Elmo and connected waterbodies, Bde Maka Ska, and Pool 2 of the Mississippi River:
The value for fish tissue is a maximum 0.37 nanograms PFOS per gram (ng/g) in fish tissue
The value for water is a maximum 0.05 ng/L PFOS in water
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The threshold for the fish in Lake Elmo is .37 ng/g.
.37 ng/g = .37 ppb = 370 ppt.
The state says it’s a threat to health if people consume fish containing more than 370 parts per trillion of PFOS. Meanwhile, across much of the rest of the state, people are free, even encouraged, to eat as much fish as they want with concentrations up to 10,000 ppt.
The limits on PFOS in water in Lake Elmo provide a valuable lesson to the nation. The value for water in the lake is a maximum 0.05 ng/L PFOS. That’s .05 parts per trillion. The folks in Minneapolis are more conservative than the European Union which has set a standard of .65 ppt in inland surface waters.
For comparison, PFOS drains into the Chesapeake Bay from the Navy’s research lab in Chesapeake Beach at concentrations of 3,294.6 ppt. That’s 65,892 times more than what Minnesota allows for Lake Elmo.
So, let’s see, if the water can have up to .05 ppt of PFOS and the stuff bioaccumulates in fish at 7,000 times that, then Minnesota says it’s OK to consume fish with up to 350 ppt of PFOS - and that’s very close to the 370 ppt limit in the .37 ng/g fish advisory for the lake. The state does not regulate any other PFAS compounds in fish, while current testing can detect 3 dozen varieties.
With the EPA on the sidelines, protecting human health from PFAS in fish is left to individual states. Minnesota, with its awful record, is ahead of most states in this realm.