By Grace van Deelen
People who eat just one US 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 US government data derived from more than 500 fish samples revealed that the majority of freshwater fish in the country are highly contaminated with per- and poly-fluoroalkyl substances (PFAS) at levels almost 300 times higher than those found in commercially 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 the fish, averaging 74% of the total, according to the study. The US Environmental Protection Agency (EPA) considers PFOS a hazardous substance that “may present a substantial danger to human health.”
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 fish meals would likely be a significant source of exposure.
Locally caught fish represent an important US food source, especially for people living on a low income. About 660,000 people in the US eat fish they catch themselves 3 or more times per week.
“Consuming a single freshwater fish could measurably increase PFAS levels in your body,” said David Andrews, a senior scientist at the Environmental Working Group (EWG) and one of the authors of the paper. “These fish are incredibly contaminated.”