The study found that the highest levels of contamination are found in fish from the Great Lakes. Eating one serving of US freshwater fish contaminated with median PFAS levels could be equivalent to drinking highly contaminated water every day for a month. PFAS chemicals, also known as "forever chemicals," do not naturally break down and have been linked to serious health problems such as cancer, high cholesterol, and kidney disease.

(EPA) and the Food and Drug Administration (FDA) since 2013. The EPA found that all but one of the 501 samples tested had elevated PFAS levels. Wild caught fish from streams and rivers had median PFAS levels that were 280 times higher than commercially caught fish sold in grocery stores.

Farm-raised freshwater fish had significantly lower levels of PFAS, possibly due to farms using groundwater as a source instead of contaminated rivers or lakes. The highest levels of PFAS were found in species of bass and catfish, while chinook and coho salmon had the lowest relative levels. Fish caught near urban areas typically had higher levels of contamination. The issue is particularly challenging for low-income residents who rely on fishing or cultural practices for food.

Despite the findings, the EPA and FDA have not issued warnings about the dangers of consuming contaminated fish. Fish advisories are issued at the state level and vary across the country, often based on outdated EPA health advisories that allow higher levels of chemicals than the revised levels issued this year. The situation presents a frustrating problem with no clear solution. Eliminating further sources of PFAS pollution is necessary, but lakes that do not regularly turn over water could remain contaminated for decades. While the study does not discourage fishing entirely, it recommends avoiding consuming freshwater fish unless there is clear information that they are not contaminated.