Unveiling\nPriority Emerging PFAS in Taihu Lake Using\nIntegrated Nontarget Screening, Target Analysis, and Risk Characterization

Amidst\ntightening regulations, the proliferation of next-generation\nper- and polyfluoroalkyl substances (PFAS) necessitates a deeper understanding\nof their environmental fate and potential risks. Here, we conducted\na comprehensive assessment of PFAS in the water and sediment of Taihu\nLake, incorporating both nontarget and target screening, seasonal\nand geographical variation analysis, and risk prioritization. A total\nof 58 PFAS from 13 classes were identified, revealing complex PFAS\ncontamination. In addition to short-chain perfluoroalkyl carboxylates\n(PFCAs) and sulfonates (PFSAs), bis(trifluoromethanesulfonyl)imide\n(Ntf2) and perfluoro-2,5-dimethyl-3,6-dioxo-heptanoic acid (C7 HFPO-TA)\nexhibited relatively high concentrations in water, with median values\nof 21.7 and 5.72 ng/L, respectively. Seasonal and geographical variation\nanalysis revealed elevated levels of C7 HFPO-TA, Ntf2, and perfluorohexanoic\nacid (PFHxA) in the northeastern areas, suggesting transport via water\ndiversion project. Multicriteria risk prioritization identified four\nhigh priority PFAS (Ntf2, C7 HFPO-TA, PFHxA, and perfluorooctanoic\nacid (PFOA)) in water and two high priority PFAS (hexafluoropropylene\noxide dimer acid (HFPO–DA) and PFHxA) in sediment. Overall,\nthis study revealed Ntf2 and C7 HFPO-TA as priority PFAS in Taihu\nLake, underscoring the urgent necessity of evaluating risks associated\nwith these emerging PFAS.