Distribution, Partitioning, Source Apportionment, and Ecological Risk Assessment of Legacy and Emerging PFAS in Water and Sediment of the Pearl River Delta

The occurrence and risk assessment of legacy and emerging poly- and perfluoroalkyl substances (PFAS) in aquatic environments are attracting public concern due to their environmental persistence and potential risks to ecosystems and humans. This study investigated the distribution, partitioning, and ecological risk of PFAS in four rivers of the Pearl River Delta (PRD). The results showed that the mean values of ∑33PFAS in surface water and ∑30PFAS in sediment were 69 and 2.3 ng/g, respectively, with concentrations ranging from 0.13 to 1400 ng/L and 0.025 to 150 ng/g. 6:2 fluorotelomer sulfonic acid (6:2 FTSA) and perfluorooctanoic acid (PFOA) were the most abundant individual PFAS in water, while perfluorohexanoic acid (PFHxA), 6:2 FTSA, and fluorotelomer phosphate diester (di-PAP) dominated the PFAS profile in sediment. Field-derived water-sediment partitioning coefficients (Kd and Koc) were significantly correlated with the carbon chain length of PFAS (p < 0.001). Source apportionment first indicated that firefighting and metal plating (67%) were the primary sources of PFAS in the PRD. Perfluorooctanesulfonate (PFOS) was associated with high ecological risks in both surface water and sediment.