Occurrence, Bioaccumulation and Dietary Exposure Assessment of Legacy and Emerging Per- and Polyfluoroalkyl Substances (PFAS) in Freshwater Fish from Zhejiang Markets: Implications for Human Health Risks

This article assesses per- and polyfluoroalkyl substances (PFAS) exposure levels, distribution, bioaccumulation characteristics, and health risks in freshwater fish from Zhejiang Province, China. A total of 240 market-sourced fish samples (covering carnivorous, omnivorous, and herbivorous species) collected between 2022 and 2024 were analyzed for 24 PFAS congeners, including four emerging alternatives. The results revealed widespread PFAS contamination, with a detection frequency of 77.5% and median total PFAS (Σ24PFAS) concentration of 2.95 ng/g. Hexafluoropropylene oxide dimer acid (HFPO-DA), perfluorooctane sulfonate (PFOS), and perfluoroundecanoic acid (PFUnDA) were the most frequently detected congeners. PFOS exhibited the highest median concentrations in carnivorous and omnivorous fish, whereas PFUnDA was the dominant contaminant in filter-feeding and herbivorous fish. No significant difference in Σ24PFAS concentrations was observed among fish with different feeding habits, but highly significant spatial variation was found. Long-chain PFAS concentrations were significantly higher than those of short-chain PFAS and emerging alternatives, with their proportion decreasing at lower trophic levels. The estimated daily intake of Σ24PFAS and Σ4PFAS for freshwater fish consumers averaged 0.14 and 0.042 ng/kg bw/day, respectively, with approximately 0.16% of the assessed individuals exceeding the recommended threshold. This study provides critical data to support food safety management and risk mitigation strategies.