A new study by Environmental Working Group scientists finds that consumption of just a single serving of freshwater fish per year could be equal to a month of drinking water laced with the “forever chemical” PFOS at high levels that may be harmful.
Researchers calculated that eating one fish in a year equated to ingesting water with PFOS at 48 parts per trillion, or ppt, for one month.
The study bolsters EWG’s long-running calls for strict regulation of PFOS and the other toxic “forever chemicals" known as PFAS, in addition to more tests of food such as fish, since diet is thought to be a major source of PFAS exposure for Americans. The findings are a particular issue for communities with environmental justice concerns, whose survival often depends on eating freshwater fish they’ve caught.
EWG found the median amounts of PFAS in freshwater fish were an astounding 280 times greater than forever chemicals detected in some commercially caught and sold fish. The testing data, from the Environmental Protection Agency and Food and Drug Administration, showed that consuming a single meal of freshwater fish could lead to similar PFAS exposure as ingesting store-bought fish every day for a year.
Researchers calculated that eating one fish in a year equated to ingesting water with PFOS at 48 parts per trillion, or ppt, for one month
“People who consume freshwater fish, especially those who catch and eat fish regularly, are at risk of alarming levels of PFAS in their bodies,” said David Andrews, Ph.D., EWG senior scientist and one of the study’s lead authors. “Growing up, I went fishing every week and ate those fish. But now when I see fish, all I think about is PFAS contamination.”
The forever chemical found at greatest concentrations in freshwater fish was PFOS, formerly an ingredient in 3M’s Scotchgard, averaging roughly three in four of total PFAS detections.
“These test results are breathtaking,” said Scott Faber, EWG’s senior vice president for government affairs. “Eating one bass is equivalent to drinking PFOS-tainted water for a month.”
Consumption of PFOS-contaminated freshwater fish can cause significant increases in peoples’ blood serum levels of the forever chemical, creating potential health risks. Even infrequent consumption of freshwater fish can raise PFOS levels in the body.
"The extent that PFAS has contaminated fish is staggering”, said Nadia Barbo, a graduate student at Duke University and lead researcher on this project. “There should be a single health protective fish consumption advisory for freshwater fish across the country.”
The researchers analyzed data from more than 500 samples of fish fillets collected in the U.S. from 2013 to 2015 under monitoring programs by the EPA, the National Rivers and Streams Assessment and the Great Lakes Human Health Fish Fillet Tissue Study. The median level of total PFAS in fish fillets was 9,500 nanograms per kilogram, with a median level of 11,800 nanograms per kilogram in the Great Lakes.
“PFAS contaminate fish across the U.S., with higher levels in the Great Lakes and fish caught in urban areas,” said Tasha Stoiber, Ph.D., an EWG senior scientist and another co-author. “PFAS do not disappear when products are thrown or flushed away. Our research shows that the most common disposal methods may end up leading to further environmental pollution.”
Freshwater fish are an important source of protein for many people, and PFAS contamination threatens those who cannot afford to purchase commercial seafood. Communities that depend on fishing for sustenance and for traditional cultural practices are inordinately harmed. This makes exposure to chemical pollutants in freshwater fish a textbook case of environmental injustice.
“Identifying sources of PFAS exposure is an urgent public health priority,” said Stoiber.