Poly- and perfluoroalkyl substances (PFAS) in marine and freshwater fish muscle tissue from Shandong Province and implications for human exposure.

Sixteen poly-and perfluoroalkyl substances (PFAS) were analyzed in ten marine fish species and five freshwater fish species with a total of 186 samples, all of which are very popular in China diets. Despite strict regulations, PFOS remained the predominant PFAS, being detected in all samples across all fish species, with median concentrations ranging from 0.058 to 1.71 ng g-1 ww. Aditionally, six long-chain PFCAs (PFOA, PFNA, PFDA, PFUdA, PFDoA, and PFTrDA) and an emerging PFAS (6:2 Cl-PFESA) were found in most of the fish with their detection frequencies exceeding 80 % or very close to 80 %, while PFHxA (a short-chain PFAS) and PFHxS were less frequently detected (<60 %). Differences of PFAS levels among various fish species were found, which may be due to the biological and ecological factors. The more stringent reference dose (RfD) was used in each PFAS to assess health risk to local residents via fish consumption. For the low consumption population, the total hazard ratio (HR) values of PFAS were less than 1 in all the fish species. However, for the high consumption population, 60 % of fish species had total HR values that exceeded 1, indicating that frequently consumption of fish may pose a potential health risk to local residents.