title: Characterizing direct emissions of perfluoroalkyl substances from ongoing fluoropolymer production sources: A spatial trend study of Xiaoqing River, China.
abstract: The spatial trend of perfluoroalkyl substances (PFASs) along Xiaoqing River and its tributaries was studied to characterize isomer profiles and quantify emissions from fluoropolymer (FP) manufacturers in China. Substantially elevated ∑PFAS concentrations downstream of tributary 4 demonstrated that the emissions from this FP manufacturer dominated total riverine discharges. Isomer profiles of perfluorooctanoic acid (PFOA) in water displayed a stepwise increase in percentage branched PFOA downstream of tributary 3 (14.0%) and 4 (22.7%) reflecting the importance of FP sources. Strong positive correlations between PFOA isomers in water downstream of tributary 4 indicated that isomer profiles were conserved from emission sources to the final reservoir. Riverine discharges of PFOA (23-67 t/yr) were in agreement with theoretical emission calculations from FP production (68 t/yr) whereas large discrepancies between the two methodologies were observed for perfluorobutanoic acid and perfluoropentanoic acid. Collectively, this study fills critical knowledge gaps for understanding ongoing global sources of PFASs.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Norwegian Institute for Air Research (NILU), 9296 Tromsø, Norway.
authors.forename: Robin
authors.initials: R
authors.lastname: Vestergren
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Song
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China; School of Chemical & Environment Engineering, China University of Mining and Technology, Beijing 10083, China.
authors.forename: Xiameng
authors.initials: X
authors.lastname: Niu
authors.affiliation: School of Chemical & Environment Engineering, China University of Mining and Technology, Beijing 10083, China.
authors.forename: Chunhui
authors.initials: C
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: caiyaqi@rcees.ac.cn.
authors.forename: Yaqi
authors.initials: Y
authors.lastname: Cai
mesh_terms: D002210:Caprylates / Q000032:analysis* / Q000737:chemistry; D002681:China; D004784:Environmental Monitoring; D005466:Fluorocarbons / Q000032:analysis* / Q000737:chemistry; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D002210:Caprylates; D005466:Fluorocarbons; D014874:Water Pollutants, Chemical; C033094:perfluorobutyric acid; C023036:perfluorooctanoic acid
keywords: Isomer fractionation; PFOA isomers; Per- and polyfluoroalkyl substances (PFASs); Source tracking