Pollution Characteristics and Ecological Risks of Per- and Polyfluoroalkyl Substances in the Qiantang River Basin (Fuchun River)
This study investigated the occurrence and distribution of 27 per- and polyfluoroalkyl substances (PFAS) in surface water and sediment of the Fuchun River, a tributary of the Qiantang River Basin. Surface water samples were analyzed using ultra-performance liquid chromatography coupled with high-resolution mass spectrometry. Total PFAS concentrations (∑PFAS) in surface water ranged from 30.04 to 105.26 ng/L, with mean and median values of 59.64 ng/L and 51.43 ng/L, respectively. The dominant compounds were perfluorooctanoic acid (PFOA), hexafluoropropylene oxide dimer acid (GenX), and perfluorobutanoic acid (PFBA). Concentrations generally decreased from upstream to downstream, consistent with previous studies. Notably, GenX levels were significantly elevated compared to earlier reports. In sediment, ∑PFAS concentrations ranged from not detected (ND) to 0.59 ng/g dry weight, with mean and median values of 0.14 ng/g and 0.11 ng/g, respectively. PFOA and perfluorooctanesulfonic acid (PFOS) were the primary sediment contaminants. Source apportionment indicated that industrial wastewater discharge and sewage treatment plant effluents were the main sources of PFAS in the river. Risk assessment using risk quotients suggested low ecological risks to aquatic organisms for most detected PFAS. However, the presence of short-chain and novel PFAS warrants further investigation due to potential unknown risks.