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Per- and Polyfluoroalkyl Substances (PFAS) are a group of contaminants of emerging concern that have been drawing numerous attention in recent years. They are highly persistent in the environment and may pose adverse impacts to marine ecosystems. Moreover, consuming seafood is a primary pathway of human exposure to PFAS. Dr. Cheng-Shiuan Lee, Assistant Research Fellow at the Research Center for Environmental Changes, Academia Sinica, collaborated with teams from Stony Brook University, Beneath the Waves, and Cape Eleuthera Institute, acquiring muscle tissue samples from various shark species for PFAS analysis from two contrasting marine ecosystems: the New York Bight (NYB) and the waters of the Bahamas Archipelago.
This study is the first to report on PFAS in multiple shark species along the northwest Atlantic coast. Sharks living along the coast of New York exhibited a greater diversity of PFAS and their precursors, and had an average total PFAS concentration five times higher than those found in samples from the Bahamas. PFAS compositions and isomer ratios also revealed different pollution sources in these two places. The accumulation of PFAS in sharks was primarily from water and dietary intake, with the contribution of each exposure pathway potentially varying in response to the carbon chain length of PFAS compounds. There was no significant correlation between PFAS concentrations and the sharks' length or gender. Ultra-long-chain PFAS (carbon chain C ≥ 10) showed significant positive correlations with stable nitrogen isotopes (δ¹⁵N) and total mercury only in some shark species. This suggests that although PFAS can accumulate in marine organisms, their accumulation mechanisms and patterns differ from those of traditionally studied bioaccumulative pollutants. Our results indicate the great impact of anthropogenic contaminants on coastal ecosystems adjacent to a dense and populated metropolitan area. The dataset of PFAS in diverse sharks from the coastal Northwest Atlantic Ocean in this study can serve as a baseline for policy-making against PFAS contamination in these two critical marine ecosystems and seafood safety for human exposure. This research has been published on July 12, 2024, in Environmental Science & Technology.