Pollution

Study finds high levels of 'forever chemicals' in freshwater fish

U.S scientists found the median levels of PFAS in freshwater fish were more than 270 times higher than those detected in commercially caught fish.

A trout swimming in a lake.
Andrew Muir / Great Lakes Fishery Commission via AP
SMS

A new study from Environmental Working Group scientists found that eating just one freshwater fish could be the equivalent of drinking a month’s worth of water contaminated with PFOS. That's a set of "forever chemicals" in the same family as PFAS.

Perfluoroalkyl and polyfluoroalkyl substances, or PFAS, are found in nonstick and water-resistant consumer products. PFAS are commonly referred to as forever chemicals because they do not break down in the environment.

"For anyone consuming freshwater fish, we actually think this is likely their largest source of exposure to these compounds," said David Andrews, EWG senior scientist and one of the study’s lead authors.

The scientists analyzed data from over 500 fish fillet samples that were collected across the U.S. from 2013 to 2015 under monitoring programs by the EPA, National Rivers and Streams Assessment, and the Great Lakes Human Health Fish Fillet Tissue Study.

"The median level of total targeted PFAS in fish fillets from rivers and streams across the United States was 9,500 ng/kg, with a median level of 11,800 ng/kg in the Great Lakes. PFOS was the largest contributor to total PFAS levels, averaging 74% of the total," read the study in part.

Scientists found the median levels of PFAS in freshwater fish in the U.S. were more than 270 times higher than the forever chemicals detected in commercially caught and sold fish.

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The study documented eating PFOS-contaminated freshwater fish can cause an increase in blood serum levels of the forever chemical in people's bodies, which has been linked to several health conditions.

Researchers call the exposure to chemical pollutants found in freshwater fish a case of environmental injustice, writing that it "especially affects communities that depend on fishing for sustenance and for traditional cultural practices."

Scientists noted identifying and reducing sources of forever chemical exposure is an urgent public health priority.

The research, however, shows a bit of good news. From 2008 to 2014, PFOS in U.S. waterways decreased by about 30%.

However, the dangerous level of contamination in freshwater fish shows there’s still a long way to go.

In the meantime, the EWG says there are other sources of fish that are safe, including ones that come from fish farms or the ocean.

"Both saltwater fish—as well as farm catfish, farm tilapia—those levels were, on average, over 300 times lower than the results from freshwater fish across the country," Andrews said.

Andrews does not recommend dropping fish from your diet.

"We still think fish is an important source of protein. This is, people should not avoid consuming fish, but, whenever possible, based on what we know, it's really prudent to seek out commercial fish," he said.

You can do this by checking the packages of frozen fish or asking the grocery clerk behind the fresh fish counter where it was caught.

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