Bioaccumulation and trophic transfer characteristics of emerging and legacy per- and polyfluoroalkyl substances in Laizhou Bay, China

Both emerging and legacy per- and polyfluoroalkyl substances (PFASs) exhibit bioaccumulative and potentially biomagnifying properties, posing risks to ecosystem and human health. This study focused on 26 legacy and emerging PFASs, investigating their concentration profiles, composition, and trophic transfer characteristics in major marine organisms from Laizhou Bay. The results demonstrated that both legacy and emerging PFASs extensively contaminated marine organisms in Laizhou Bay. Variations in PFASs concentration and compositions among different species were strongly associated with species-specific traits, trophic levels, and dietary preferences. The mean log bioconcentration factor (BAF) values of PFASs increased with carbon chain length, with perfluoroalkyl sulfonates (PFSAs) showing higher average log BAF values compared to perfluoroalkyl carboxylates (PFCAs) of the same chain length. In the study area, emerging alternatives such as perfluoro-1-butane-sulfonamide (FBSA) (4.25) and 6:2 fluorotelomer sulfonic acid (6:2 FTSA) (4.52) exhibited log BAF values exceeding 3.7, indicating significant bioaccumulation potential. Moreover, the emerging substitute 6:2 chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA) showed a trophic magnification factor (TMF) of 1.95—exceeding the bioamplification threshold of 1—providing strong evidence of trophic-level transfer and increasing contaminant concentrations in higher trophic organisms. The estimated daily intake (EDI) of perfluorooctanoic acid (PFOA) was relatively high, with a hazard ratio (HR) > 1, highlighting potential health risks for local residents near Laizhou Bay who regularly consume contaminated seafood. • Legacy and emerging PFAS extensively contaminate marine organisms in Laizhou Bay. • PFAS variation is shaped by species-specific traits, trophic levels, and diet. • Emerging PFAS like FBSA and 6:2 FTSA demonstrate bioaccumulation potential. • PFAS exhibit trophic magnification effects in Laizhou Bay. • High EDI values for PFOA and FBSA indicate health risks from seafood intake.