By Grace van Deelen
People who eat just one U.S. freshwater fish a year are likely to show a significant increase of a cancer-causing chemical in their bloodstream, new research warns.
An analysis of U.S. government data derived from more than 500 fish samples revealed that the majority of fish living in streams, rivers and lakes across the country are contaminated with per- and poly-fluoroalkyl substances (PFAS) at levels almost 300 times higher than found in fish from other sources, including ocean and farmed fish, according to the paper published recently in the journal Environmental Research.
Importantly, perfluorooctanesulfonic acid (PFOS), a type of PFAS known to be particularly harmful, was the largest contributor to total PFAS levels found in freshwater fish samples, averaging 74% of the total, according to the study.
The U.S. Environmental Protection Agency (EPA) considers PFOS specifically to be a hazardous substance that “may present a substantial danger to human health” due to its links to cancer and effects on reproductive, developmental, and cardiovascular health, and warns that the chemical “may present a substantial danger to human health.” Other PFAS have also been linked to cancer, immune deficiencies, thyroid disease, and other health problems.
The research found that eating one serving of fish at the median PFOS contamination level was equivalent to consuming one month’s worth of drinking water contaminated at 2400 times the recommended health advisory limit set by the Environmental Protection Agency (EPA). The study determined that “even occasional consumption” of wild, freshwater fish would likely be a significant source of exposure.