Per- and polyfluoroalkyl substances (PFAS) measured in seafood from a cross-section of retail stores in the United States

Seafood is a dominant source of human exposure to per-and polyfluoroalkyl substances (PFAS). Existing studies on foodborne PFAS exposure have focused on only a subset of these compounds. Here, we conducted a pilot study to screen 33 PFAS in 46 seafood samples from a cross-section of national and local stores in the US. Low levels of 8 PFAS were measured in 74% of the samples, predominated by PFHxS (59%). Total PFAS ranged between 0.12 and 20 ng/g; highest levels were measured in Estonia-sourced smelt. The highest median levels were of PFOA (0.84 ng/g) with elevated concentrations found in Chinese clams (2.4 ng/g), which exceeds the EU established maximum limits (MLs). Measured levels of PFHxS, PFOA, and PFNA also exceeded MLs in 24%, 7%, and 5% of the samples, respectively. For average consumption levels, exposures were below the EU established tolerable weekly intakes (TWIs). However, for more frequent consumption of flounder, catfish, and cod, exposures exceeded regulations, which warrants identifying vulnerable high seafood consuming populations. Accidental PFBS cross contamination from sample storage bags resulted in 100% detection in samples, highlighting the problem with post-purchase food handling practices such as storage and cooking that could also have a sub-stantial impact on human exposure, potentially in larger amounts than the (sea)food itself.