[Occurrence, Input, and Seasonal Variations of Poly-and Perfluoroalkyl Substances (PFASs) in Rivers and Drain Outlets from the Dalian Coastal Area, China].

Concentrations of 19 PFASs (poly-and perfluoroalkyl substances) in riverwater, coastal wastewater, and effluents from wastewater treatment plants (WWTPs) directly discharged into the Dalian coastal area were measured and their inputs were calculated accordingly. For riverwater samples, the total PFAS concentration ranged from 9.85 to 757 ng·L, with a median of 74.7 ng·L. For drain outlets, the total PFAS concentration in wastewater ranged from 9.19 to 801 ng·L, with a median of 29.5 ng·L. PFOS and PFOA were the dominant contributors for the PFASs in both riverwater and wastewater samples in this study. The total PFASs concentration in the industrial wastewater samples collected during the winter were found to be significantly higher than those collected in the summer. However, no seasonal variation was found for other samples. The total PFAS input into the Dalian coastal area was calculated to be 44.7 kg·a. The detection frequencies of Cl-PFESAs were low, and no 8:2Cl-PFESA was detected in all collected samples.