Quantifying the Trophic Transfer Process and Dietary Source of Legacy and Emerging Per- and Polyfluoroalkyl...

Sea is one of the global final reservoirs of per- and polyfluoroalkyl substances (PFAS), a group of anthropogenic syntheic chemicals of global concern. However, knowledge regarding trophic transfer and biomagnification of PFAS along the marine food web remains poorly understood. Here, to address this gap, a tropical marine food web including 60 species were collected from the Bohai Sea for an analysis of 39 representative PFAS. We found that the emerging PFAS dominated the total PFAS compositions (51.77%), majorly attributed to the significant impacts from the replacement of long-chain legacy PFAS with novel alternatives. Many long-chain legacy PFAS showed trophic magnification factors larger than 1.0, which suggests their considerable biomagnification potential in this food web. A Bayesian MixSIAR model further revealed that conch, shrimp, and crab jointly account for 78.1% and 91.2% of diet proportions for cephalopod and pelagic fish, respectively. The Monte-Carlo-model-simulated maximum perfluorooctanoic acid (PFOA)-equivalent hazard indexes induced by fish consumption were 0.61-0.82 and 1.01-1.33 for adult and children, respectively, and showed an increasing pattern with the rising tropical level. Our findings demonstrate the prevalence of PFAS in the Bohai Sea and highlight the crucial role of diet sources in PFAS bioaccumulation in marine food webs.