PerfluorinatedCompoundsinAquaticOrganismsatVariousTrophicLevelsina GreatLakesFoodChain Kurunthachalam Kannan, 1 Lin Tao, 1 Ewan Sinclair, 1 Stephanie D. Pastva, 2 Dave J. Jude, 3 John P. Giesy 2,4 1 Wadsworth Center, New York State Department of Health and Department of Environmental Health and Toxicology, School of Public Health, State University of New York at Albany, Empire State Plaza, PO Box 509, Albany, New York 12201-0509, USA 2 National Food Safety and Toxicology Center, Department of Zoology, Center for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824-1311, USA 3 School of Natural Resources and the Environment, University of Michigan, 501 East University, Ann Arbor, Michigan, USA 4 Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong Received: 15 June 2004 /Accepted: 20 August 2004 Abstract. Trophic transfer of perfluorooctanesulfonate (PFOS) and other related perfluorinated compounds was examined in a Great Lakes benthic foodweb including water– algae–zebra mussel–round goby–smallmouth bass. In addition, perfluorinated compounds were measured in livers and eggs of Chinook salmon and lake whitefish, in muscle tissue of carp, and in eggs of brown trout collected from Michigan. Similarly, green frog livers, snapping turtle plasma, mink livers, and bald eagle tissues were analyzed to determine concentrations in higher trophic-level organisms in the food chain. PFOS was the most widely detected compound in benthic organisms at various trophic levels. Concentrations of PFOS in benthic invertebrates such as amphipods and zebra mussels were approximately 1000-fold greater than those in surrounding water, which suggested a bioconcentration factor (BCF; con- centration in biota/concentration in water) of 1000 in benthic invertebrates. Concentrations of PFOS in round gobies were two- to fourfold greater than those in their prey organisms such as zebra mussels and amphipods. Concentrations of PFOS in predatory fishes (Chinook salmon and lake whitefish) were 10 to 20-fold greater than those in their prey species. Concen- trations of PFOS in mink and bald eagles were, on average, 5- to 10-fold greater than those in Chinook salmon, carp, or snapping turtles. Because of the accumulation of PFOS in liver and blood, the biomagnification factor (BMF) of perfluori- nated compounds in higher trophic-level organisms such as salmonid fishes, mink, and eagles were based on the concen- trations in livers or plasma. Overall, these results suggest a BCF of PFOS of approximately 1000 (whole-body based) in benthic invertebrates, and a BMF of 10 to 20 in mink or bald eagles, relative to their prey items. Eggs of fish contained notable concentrations of PFOS, suggesting oviparous transfer of this compound. PFOA was found in water, but its bio- magnification potential was lower than that of PFOS. Perfluorooctane sulfonate (PFOS), a fluorinated organic con- taminant, has been the subject of many recent investigations (Hansen et al. 2001; Kannan et al. 2001a,b; Kannan et al. 2002a,b,c,d; Moody et al. 2002; Van de Vijver et al. 2003; Martin etal. 2004; Stock etal. 2004). Widespread distribution of PFOS in wildlife tissues collected from several regions of the globe has been reported (Giesy and Kannan 2001, 2002; Martin et al. 2004). Additional perfluorinated organic contaminants, such as perfluorohexanesulfonate (PFHS), perfluorooctanoate (PFOA), and perfluorooctanesulfonamide (PFOSA) have been reported to occur in the environment, although at lower con- centrations and frequencies than PFOS. Earlier studies have suggested that concentrations of PFOS tend to be higher in predatory organisms than in lower trophic-level organisms of aquatic food chains (Kannan et al. 2002c). For instance, fish- eating birds (e.g., bald eagles) and mammals (e.g., mink) contained some of the highest concentrations of PFOS reported thus far. Nevertheless, earlier studies measuring concentrations of PFOS in biota have focused primarily on higher trophic-level organisms. Studies reporting the occurrence of PFOS in aquatic organisms at lower trophic levels in a food chain are scanty. In order to determine the biomagnification potential of PFOS in aquatic food webs, we need to measure concentrations in organisms at various trophic levels. In this study, we have measured concentrations of PFOS, PFHS, PFOA, and PFOSA in water, benthic algae, amphipods, zebra mussel (Dreissena polymorpha), crayfish, round gobies (Neogobius melanosto- mus), and smallmouth bass (Micropterus dolomieui) collected from three riverine locations. This represents a characteristic benthic food chain of the Great Lakes since the invasion of the Great Lakes by zebra mussels in the late 1980s; and by round gobies in the early 1990s (Hanari et al. 2004). Correspondence to: Kurunthachalam Kannan; email: kkannan@ wadsworth.org Arch. Environ. Contam. Toxicol. 48, 559–566 (2005) DOI: 10.1007/s00244-004-0133-x