Occurrence, source apportionment, and ecological risk of perfluorinated substances (PFASs) in Yangtze River, China

Due to their persistence, bioaccumulation, and resistance to degradation, perfluorinated substances (PFASs) have significant impacts on the environment and human health. This study comprehensively analyzed and assessed the occurrence characteristics, sources, and potential ecological risks of 13 PFASs in the Yangtze River. The results indicated that the concentrations of ΣPFASs range from 5.1 to 57.7 ng/L, with more severe pollution downstream and perfluorobutane sulfonate (PFBuS) being the main pollutant. ΣPFASs showed a positive correlation with total organic carbon and absorbance under the condition of UV wavelength 254 nm (UV₂₅₄), and a negative correlation with total dissolved solids. Positive matrix factorization model analysis revealed that the primary sources of PFASs in the study area are food packaging, the electroplating industry, and the manufacturing and processing of fluoropolymer-containing products. The total ecological risk value of PFASs indicated that the ecological risks to algae, invertebrates, and fish are negligible. The annual load of ΣPFASs in the Yangtze River was 39.00 t, with the highest concentrations of pollutants being PFBuS (26.41 t/year), perfluorobutanoic acid (6.47 t/year), and perfluorooctanoic acid (PFOA, 3.19 t/year). While PFASs have not yet posed a risk to aquatic organisms, the increase in the use of short-chain PFASs substitutes (C4-C7) due to the regulation of PFOA and perfluorooctane sulfonate highlights the need for continued monitoring of short-chain PFASs pollution.