title: Contribution of diffuse inputs to the aqueous mass load of perfluoroalkyl acids in river and stream catchments in Korea.
abstract: Recent studies disagree regarding the contributions of point versus non-point sources to the aqueous mass loads of perfluoroalkyl acids (PFAAs). This study investigated the longitudinal change in PFAA mass load from upstream to downstream stations along rivers and/or streams to assess the relative contributions of point versus nonpoint inputs. With concentrations 10 to 100 times higher than running water, point sources such as wastewater treatment plants (WWTPs) effluent and airport ditch-outlet (ADO) water were separated from neighboring upstream and downstream running waters using principal component analysis. Source waters were characterized by certain predominant components [e.g., perfluorobutylsulfonate (PFBS) and perfluorooctanoic acid (PFOA) in WWTP effluent and perfluorohexylsulfonate (PFHxS) and perfluorooctylsulfonate (PFOS) in ADO water], which were minor components of running water. From a mass balance assessment of PFAA mass load, certain compounds such as PFOA and PFBS dominated the contribution of point sources to the mass load in the running water at downstream stations or in small catchment basins with high levels of industrial activity. Most of the mass load in the investigated catchments was attributable to upstream running water with a minor influence from industrial, commercial, and domestic human activities. Furthermore, the negative relationship of per capita emission factors (hereafter, EFs) with population density and a lower contribution of PFAA from WWTPs (~30% on average) compared to the running water-derived mass load at the national level indicated that diffuse inputs were more important contributors to aqueous PFAA contamination in each catchment basin as well as the entire watershed of the country (Korea). Volatile precursor compounds, which are readily dispersed to neighboring basins and transformed to PFAAs in the ambient environment, can be an important source of these diffuse inputs and will become more significant over time.
authors.affiliation: Department of Marine Science, College of Natural Science, Incheon National University, 12-1 Songdo-dong, Yeonsu-gu, Incheon 406-772, South Korea.
authors.forename: Seung-Kyu
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Key laboratory of Nature Resource of the Changbai Mountain and Functional Molecular, Yanbian University, Ministry of Education, Park Road 977, Yanji City, Jilin 133002, China.
authors.forename: Dong-Hao
authors.initials: DH
authors.lastname: Li
authors.affiliation: Environment Canada, Science and Technology Branch, 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada.
authors.forename: Mahiba
authors.initials: M
authors.lastname: Shoeib
authors.affiliation: Department of Environmental Health, School of Public Health, Seoul National University, 1 Gwanakro, Gwanak-Gu, Seoul 151-742, South Korea. Electronic address: zohkd@snu.ac.kr.
authors.forename: Kyung-Duk
authors.initials: KD
authors.lastname: Zoh
mesh_terms: D004784:Environmental Monitoring; D005466:Fluorocarbons / Q000032:analysis*; D056910:Republic of Korea; D045483:Rivers / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005466:Fluorocarbons; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Catchment basin; Emerging POPs; Mass discharge load; Non-point source; Perfluoroalkyl acids (PFAAs); WWTPs