When freshwater fish are contaminated by 'forever chemicals,' some are no longer safe to eat

PFAS exposure means some freshwater fish are
labeled 'do not eat.' Photo by Andy Wang, Unsplash

A freshwater fish fry may sound like a delectable dinner, but it may no longer be healthy because substances known as PFAS or 'forever chemicals' have polluted many freshwater fish populations. While the Environmental Protection Agency has been working on PFAS drinking water standards, "Some scientists worry that regulations for freshwater fish are lagging," reports Hannah Norman of KFF Health News. "A recent study from The Environmental Working Group found that just one serving of fish can be equivalent to a month of drinking water contaminated with 48 parts per trillion of the common chemical PFOS."

PFOS and PFOA are part of the PFAS family of synthetic chemicals, which were used to make everything from Teflon to fire-fighting foam. Their chemical structure resists environmental breakdown by nature or the human body, which means they "accumulate in the soil, water, fish and our bodies," Norman explains. According to a report from the National Academies of Sciences, Engineering and Medicine, human PFAS exposure is "associated to cancer, low birth weight and decreased responses to vaccines. . . . At least 17 states have issued PFAS-related fish consumption advisories, KFF Health News found, with some warning residents not to eat any fish caught in particular lakes or rivers."

When it comes to PFAS levels in fish, the federal government hasn't provided any dietary guidance. Instead, states are setting limits with alarming variations. Norman reports, "'Do not eat' thresholds for the general population range from 25.7 parts per billion in New Hampshire to 800 ppb in Alabama. . . . While the EPA has tested hundreds of fish for PFAS and found some samples with concerningly high concentrations, it has no plans to provide national fish consumption advisories."

There is a bit of good news. Norman reports, "The Food and Drug Administration tested saltwater fish and shellfish sold in grocery stores — including Atlantic salmon and canned tuna — and generally found far lower levels of PFAS contamination."