[Analysis of the Occurrence Characteristics of Per- and Polyfluoroalkyl Substances in the Middle-Lower Yangtze River]

Since 2022， the "Action Plan for the Control of Emerging Pollutants" and the "List of Key Control Emerging Pollutants （2023 Edition）" have been issued， which have put forward new requirements for the control of PFASs. Monitoring was conducted for 22 PFASs in April and October of 2022 and 2023. In this work， ∑PFASs concentrations ranged from 10.3 to 280.9 ng·L^-1， with an average concentration of 65.5 ng·L^-1. Short-chain PFASs （C4-C6） were detected more frequently compared to long-chain PFASs （C7-C18）. The detected concentrations of key controlled emerging pollutants such as PFOS and PFOA have decreased. In 2022， extreme concentrations of ∑PFASs were observed in specific sections along the Yangtze River， including Yueyang， Jiujiang， Zhenjiang， Taizhou， Nantong， and Suzhou. In 2023， the ∑PFASs concentrations in the main stream exhibited an increasing trend from the middle to the lower reaches， and extreme concentrations had disappeared. The changes were related to the sewage discharge volume， water flow rate， PFASs control policies， and the widespread use of PFASs substitutes in various provinces. These results indicate that， under new policies， provinces or municipalities along the middle-lower Yangtze River have achieved significant progress in controlling PFASs.