A Dartmouth-led study suggests that people who frequently consume seafood may face an increased risk of exposure to PFAS, the family of ubiquitous and resilient human-made toxins known as „forever chemicals.“ The findings stress the need for more stringent public health guidelines that establish the amount of seafood people can safely consume to limit their exposure to perfluoroalkyl and polyfluoroalkyl substances, the researchers report in the journal Exposure and Health. This need is especially urgent for coastal regions such as New England where a legacy of industry and PFAS pollution bumps up against a cultural predilection for fish, the authors write.
The study paired an analysis of PFAS concentrations in fresh seafood with a statewide survey of eating habits in New Hampshire. National data indicate that New Hampshire—along with all of New England— is among the country’s top consumers of seafood, which made the state ideal for understanding the extent of people’s exposure to PFAS through fish and shellfish.
The study also drew on New Hampshire’s extensive data on the sources and effects of PFAS, which are a staple of consumer products such as plastics and nonstick coatings. The molecular stability that makes PFAS versatile also makes them nearly indestructible, leading them to be called forever chemicals. In humans, PFAS are associated with cancer, fetal abnormalities, high cholesterol, and thyroid, liver, and reproductive disorders. The chemicals have accumulated in soil, water, and wildlife, and studies have shown that nearly all Americans have measurable amounts in their blood.
The researchers measured the levels of 26 varieties of PFAS in samples of the most consumed marine species: cod, haddock, lobster, salmon, scallop, shrimp, and tuna. The seafood studied was purchased fresh from a market in coastal New Hampshire and originated from various regions. Shrimp and lobster clocked the highest concentrations with averages ranging as high as 1.74 and 3.30 nanograms per gram of flesh, respectively, for certain PFAS compounds, the researchers report. Concentrations of individual PFAS in other fish and seafood measured generally less than one nanogram per gram.