Scientists seeking to limit human exposure to "forever chemicals"—which don't break down easily in the environment—have found alarming levels of contamination in fish caught in America's lakes and rivers. According to a study published in the journal Environmental Research, eating a single freshwater fish brings as much exposure to the toxic chemicals as drinking contaminated water for a month. The researchers examined 500 samples of fish collected under an EPA monitoring system between 2013 and 2015 and found that only one did not contain PFOS, short for perfluorooctane sulfonic acid; it's a toxin linked to health issues including cancer, liver damage, and immune system problems that was phased out of production here about 20 years ago.
"The levels of PFOS found in freshwater fish often exceeded an astounding 8,000 parts per trillion," compared to the 70 parts per trillion the EPA currently allows in drinking water, study coauthor David Andrews tells CNN. "You’d have to drink an incredible amount of water—we estimate a month of contaminated water—to get the same exposure as you would from a single serving of freshwater fish." He says anglers should strongly consider throwing their catches back instead of bringing them home for dinner. Last year, the EPA said the permitted level of PFOS in drinking water should be lowered to 0.02 parts per trillion. PFOS are part of a group of compounds calls PFAS introduced in the 1940s and used in products including nonstick coatings and firefighting foam.
The chemicals were found in fish across the US, including areas far from cities and factories. PFOS levels were highest in the Great Lakes. The Environmental Working Group, which led the research, has an interactive map of where the contaminated fish were caught. Andrews tells AFP that he grew up catching and eating fish, but he can "no longer look at a fish without thinking about PFAS contamination." The findings, he says, are "particularly concerning due to the impact on disadvantaged communities that consume fish as a source protein or for social or cultural reasons." (Read more fish stories.)