Eating your PFAS? Study warns freshwater fish could be source of the 'forever chemicals'
A lot of focus surrounding PFAS has been on how it contaminated drinking water, but a new study is focused on how we may be consuming it in our food.
Researchers with the Environmental Working Group compiled EPA data on PFAS levels in freshwater fish in the study: Locally caught freshwater fish across the United States are likely a significant source of exposure to PFOS and other perfluorinated compounds. The paper was peer-reviewed and published in Elsevier’s Environmental Research.
Between 2013 and 2015 the U.S. EPA sampled freshwater fish across the continental U.S. Every single state had at least one fish come back with elevated levels of PFAS.
“We’re really just trying to identify how are people being exposed and how can people take action to reduce that exposure,” said David Andrews, Ph.D., a senior scientist at the Environmental Working Group and one of the lead researchers who recently compiled that EPA data.
Researchers calculated what different levels of PFAS in fish would translate to in terms of PFAS-contaminated drinking water.
They found that eating an 8 oz fish with PFAS levels around 8,400 nanograms per kilogram of PFOS, one of the common types of PFAS, is the equivalent to drinking one month of water with PFOS levels of 48 parts per trillion.
The Wisconsin Department of Health Services has a safe drinking water level of 20 parts per trillion while the EPA’s interim health advisory has a value of 0.02 ppt for PFOS in drinking water.
“There’s been a lot of attention, rightly so, paid to contaminated drinking water and how can we remove PFAS contamination from drinking water. But part of this is how else are people being exposed and what are the changes that can be made to have the biggest impact,” said Andrews. “It really looks like for people consuming freshwater fish, it’s possible moving away from that may lead to the biggest change in terms of the overall exposure to these compounds.”
The study also revealed that fish sampled in the Great Lakes had higher concentrations, with the median level of PFAS being 11,800 nanograms per kilogram.
“What we did see is that those levels in the Great Lakes are concerningly high. It would take infrequent or even a single fish consumption to potentially significantly change serum levels,” said Andrews. That’s what really stood out is how infrequently you could consume fish and have it still have a measurable on the contamination on your body.”
While there’s not widespread EPA data on PFAS levels in fish that’s more recent, the researchers were able to compare a few locations that show PFAS levels have dropped slightly.
Andrews says it’s promising that the levels have gone down, but they’re still too high.
And on that note, it’s concerning to Andrews that more recent data isn’t available to pull from.
“The EPA did do sampling in 2019 and that information is not yet public. Some of that may have been delayed due to COVID and the pandemic, but there needs to be a mechanism where fish can be sampled and those results can become essentially immediately available to the public so that it can inform decision-making by states, local communities, or even individuals,” said Andrews.
Wisconsin DNR PFAS Fish Consumption Advisories
The Wisconsin Department of Natural Resources does its own testing for PFAS in fish that does include more recent data.
“We’ve been looking at PFAS in fish and wildlife dating back to about 2006 or 2007. We started to include it as a regular part of our monitoring starting about 2017. We’ve been looking at it for quite a while,” Sean Strom is a toxicologist for the DNR.
In 2022, fish consumption advisories were issued for several species harvested in water bodies in more than five counties.
This included limiting how much people should eat for five species in Lake Mohawksin in Lincoln County.
This week, PFAS Fish Advisories were issued for Lake Wausau in Marathon County and the Stevens Point Flowage in Portage County.
Strom says fish in larger lakes, the Mississippi River, and the Wisconsin waters of Lakes Michigan and Superior are tested for PFAS with some regularity.
For other rivers and lakes, PFAS testing is usually done in areas of concern.
“It’s kind of a two-pronged approach of doing routine monitoring and then more targeted monitoring,” said Strom.
Strom says the DNR and Department of Health Services follow guidelines set by the Great Lakes Consortium for Fish Advisories when issuing PFAS fish advisories in Wisconsin.
Those advisories are based on a document created in 2019 that uses EPA drinking water advisories set in 2016. Back then the EPA established the health advisory levels at 70 parts per trillion. It was updated in 2022 to 0.02 parts per trillion.
Strom still encourages people to fish but to check for any advisories before you go. He emphasized these are advisories, they’re not laws or regulations restricting people.
“It’s just advice that’s put out jointly by both the DNR and Department of Health Services to help reduce the exposure to potential contaminants in fish,” said Strom.
Andrews recommends people be cautious about the fish they catch.
“The ultimate answer is that there shouldn’t be this contamination in the fish and people shouldn’t be concerned about it, but it’s there so everyone should know about it. Where fishing is very important, people go out regularly and they consume these fish. I think more needs to be done to address this potential source of exposure,” said Andrews.
PFAS may lead to adverse health effects like high cholesterol levels, thyroid disease, and decreased fertility in women.
Andrews says the silver lining to this is that commercial fish tested in grocery stores had extremely low levels of PFAS to the point where they’re not of concern.
Though he recognizes that’s little comfort for people who enjoy fishing like himself.
“I grew up fishing a ton, probably every week if not more often. I do little bit less now, but I love to take my kids out fishing. I understand the draw and importance there. It’s a great way to get away from everything. I find it frustrating and angering that now I go out fishing and it makes me think of PFAS contamination,” said Andrews.