Freshwater fish found to have high levels of ‘forever chemicals’ – WBUR News


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Smallmouth bass are one of the freshwater fish species found to have higher concentrations of PFAS. (Getty Images)

A new study found high levels of toxic “forever chemicals” in freshwater fish nationwide. Compared to store-bought fish, the fish examined in the study had an average of nearly 280 times more of these toxic chemicals called PFAS. Particularly high levels were found in fish caught in urban areas.

This study, published in Environmental Research, is concerning news for recreational fisherman who cook up what they catch and communities that rely on subsistence fishing or have cultural traditions that involve fishing. Previous work by the Food and Drug Administration found commercially available fish in grocery stores and restaurants generally had relatively low PFAS levels; experts say store-bought fish are often from offshore fisheries that seem to be less affected.

“Even infrequent consumption of, for example, four meals per year [of freshwater fish] could potentially double the amount of PFOS in your body,” said Tasha Stoiber, one of the study authors and a scientist at the advocacy organization the Environmental Working Group. PFOS is one of many thousands of types of PFAS chemicals.

Some governmental bodies, including in the state of Massachusetts, have focused on measuring and regulating PFAS in drinking water. This study adds to a growing understanding that food can also be a significant source of PFAS exposure.

“This is a consequence of many decades of an unregulated class of chemicals. That pollution has now accumulated in fish,” said Stoiber.

PFAS are manmade chemicals that are used in a wide range of products, everything from firefighting foams to dental floss to nonstick pots and pans. The chemicals are useful in repelling water, oil and grease. However, the chemicals — which take a very long time to break down — are linked to a long list of health concerns, including suppressing the immune system, disrupting the endocrine system and increasing the risk of certain types of cancer.

The study examined over 500 fish samples and 44 different species gathered by the Environmental Protection Agency between 2013 and 2015 across the U.S. Smallmouth bass, largemouth bass and channel catfish tended to have some of the higher levels of PFAS. Other studies have found that populations that are more likely to consume fish — including licensed anglers and Burmese refugees in Western New York state — have higher levels of PFAS in their blood compared to the general population.

Given the level of PFAS contamination across the country, the findings did not surprise Elsie Sunderland, who is an environmental chemist at Harvard and was not involved in the study.

“But this is the first time it has been shown that for people who have traditional practices that include a lot of local fishing activity or there’s a community fishery that they’re very highly exposed by consuming relatively small amounts of fish. So just one meal,” she said.

She pointed out that other toxins found in fish, such as mercury or PCBs, often accumulate in older fish that are higher on the food chain. In contrast, “PFAS seem to really reflect site-specific contamination,” said Sunderland.

“The big message from that is we really need consumption advisories across the country,” she said, adding that the chemicals are still being widely produced.

Sunderland would like to see movement on both the state and federal level to provide local fish advisories and information on how much can safely be consumed. She would also like to see PFAS chemicals regulated at the federal level.