Factors Affecting the Distribution of Perfluorinated Compounds in Sediments from Lake Shihwa, Korea

1. Factors Affecting the Distribution of Perfluorinated Compounds in Sediments from Lake Shihwa, Korea Jonathan E. Naile1, HoonYoo2, Thomas M. Jenkins3, John W. Washington1 1United States Environmental Protection Agency, National Exposure Research Laboratory, Ecosystems Research Division 2National Reseach Council 3Senior Service America, Inc ABSTRACT Perfluorinated compounds (PFCs) are ubiquitously distributed in various environmental media including water, soil, sediment, and biota. PFCs have also been shown to biomagnify in both aquatic and terrestrial environments. Lake Shihwa is an artificial saltwater lake, located on the west coast of Korea, which has been receiving industrial wastewater discharges from the Shihwa and Banweol Industrial complexes. Previous studies have reported elevated levels of PFCs in both water and biota samples. Sediment samples were collected from inside and outside the Lake Shihwa industrial complex, where some of the highest water concentrations ever measured have been reported. Nine perfluorocarboxylate acids (PFCAs), five perfluorosulfonate acids (PFSAs) and six precursors (amides, acetates, and fluoro telomers) of perfluorooctane sulfonate (PFOS) were surveyed using UPLC-MS-MS. In addition to determining sediment contamination profiles for PFCs and their precursor, other sediment physical characteristics were measured to understand the key factors affecting distribution dynamics of these halogenated chemicals in this semi-closed artificial sea-lake environment. Interestingly, sampling locations where high waterborne or biota contamination had been previously reported coincided with highly contaminated sediment sites, supporting the existence of local point sources. Concentrations of PFCs ranged from below the method detection limit (MDL=150 pg/g) to as high 246,805 pg/g dry weight. Two fluorotelomer alcohols (6:2FTS, 8:2 FTS) ranged from below the MDL (=100 pg/g each) to as great as 277 and 226 pg/g, respectively. In addition, two sulfonamides (sFOSA, FOSAA), and two acetates (methylated, ethylated) were found at levels as high 32,172 pg/g (EtFOSAA) and 2,006 pg/g (MeFOSAA). The log-transformed distribution coefficient (LogKd), was found to be significantly associated with fluorinated carbon number (0.18 increment per C-F2unit addition). Overall this study provides useful field based distribution data for a wide variety of PFCs, which will be useful for future modeling efforts. PFSAs/FOSAs Data in Lake Shihwa Sediments (pg/g dw) PFCA concentrations in Sediments (pg/g dry wt) Background • PFCs have been produced and used in large quantities since the 1950s • The C-F covalent bond is very strong and as a result PFCs are resistant to hydrolysis, photolysis, metabolism, and biodegradation, but precursors such as fluorotelomer alcohols and perfluorosulfonamides/acetates have been shown to degrade to more stable PFCs • Wide range of applications from surfactants and fire-fighting foams to pharmaceuticals • Globally ubiquitous in both remote and urban environments • Large scale production of PFOS and PFOA has been mostly phased out in North America but significant manufacturing still persists in some Asian countries • Many unanswered questions still remain with respect to precursors, distribution and partitioning throughout the environment Study Location • The Shihwa and Banweol industrial complexes are located on the western coast of Korea approximately 30 km south of Seoul • Lake Shiwa is an artificial saltwater lake which receives industrial wastewater discharge from both industrial complexes • Historical contamination of organic compounds and metals in water and sediment • Among the greatest water concentrations of PFOS and other PFCs ever reported • Home to a variety of terrestrial and aquatic wildlife species, e.g., migratory birds • Sediment and water samples were collected from inland streams, Lake Shiwa, and Gyeonggi Bay Sorption isotherms for PFSAs and PFCAs Freundlich equation: Csed = Kf(Cw)n log Csed = nlogCw + log Kf Affects of Chain Length and Salinity on Sediment Distribution References Rostkowski et al. (2006) Perfluorinated compounds in streams of the Shiwa Industrial Zone and Lake Shiwa, South Korea. Environmental Toxicology and Chemistry. (25) 9, pp 2374-2380 Higgins et al. (2006) Sorption of perfluorinated surfactants on sediments. Environmental Science and Technology. 40, pp 7251-7256 Yoo et al. (2009) Perfluoroalkyl acids in marine organisms from Lake Shiwa, Korea. Archives of Environmental Contamination and Toxicology. 57, pp 552-560 Naile et al. (2010) Perfluorinated compounds in water, soil and biota from estuarine and costal areas of Korea. Environmental Pollution. 158, pp 1237-1244 The log-transformed distribution coefficient Kd, was found to be significantly associated with fluorinated carbon number on studied PFCs (0.18 increment per C-F2unit addition), but no statistical associations between Kd and salinity were found.