Occurrence and Distribution Profiles of Perfluoroalkyl and Polyfluoroalkyl Substances in Water and Sediment of the Lower Reaches of the Yellow River.

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are known for their potential for long-range transport and significant bioaccumulation, and long-term exposure poses risks to both ecosystem integrity and public health. Globally, an increasing number of aquatic systems domestically and internationally have reported PFAS contamination, highlighting the growing severity of this issue. This research focuses on the lower section of the Yellow River, a vital water body in China, presenting a detailed analysis of PFAS pollution characteristics, source identification, and associated health risks. Surface water and sediment samples were collected seasonally from seven locations along the Pingyin-Jinan reach. Concentrations of 21 target PFASs were measured using ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry. The findings indicate that no polyfluoroalkyl substances were detected in the study area, and the main perfluorinated pollutants in both water and sediment were perfluorooctanoic acid and perfluorobutanoic acid (PFBA), suggesting a transition toward shorter chain compounds in this stretch of the river. Through principal component analysis-multiple linear regression (PCA-MLR) and Spearman correlation analysis, industrial discharges and atmospheric deposition were identified as the two principal sources of PFASs. Ecological risk evaluation indicated that PFBA, PFPeA, PFBS, PFHxA, and PFOS pose low to negligible risks to the aquatic environment, whereas PFOA presented a moderate risk, particularly at site S2 near a tributary confluence. Human health risk assessment indicated that current PFAS levels in the lower Yellow River pose negligible risks to residents.