Assessment of Perfluorinated Compounds in Fish from U.S. Rivers

EPA’s Office of Water and Office of Research and Development are collaborating to conduct assessments of U.S. river contaminants that are of emerging concern for human health.  These assessments include analysis of fish tissue from about 150 urban river locations (≥5th order based on 1:100,000-scale Strahler order) throughout the lower 48 states for the presence of perfluorinated compounds (PFCs).  This national-scale urban river study is EPA’s first broad assessment of CECs in fish using a statistically-based sampling design.  It is being conducted under the framework of EPA’s National Rivers and Streams Assessment (NRSA), a probability-based survey designed to assess the condition of the Nation’s streams and rivers.  Samples were collected for the study in 2008 and 2009 during June through October sampling seasons.  Field teams across the country applied consistent methods to collect one fish composite sample at every sampling location.  Each composite sample consisted of five similarly-sized adult fish of the same species, and the field teams targeted species that are commonly consumed by humans.  Largemouth and smallmouth bass were the primary species collected for the study, accounting for 34% and 24% of all fish composites, respectively.  Fillets from fish composite samples were analyzed for 13 PFCs, including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).  PFCs, and PFOA and PFOS in particular, are heat stable chemicals that repel water and oil, and are commonly used in stain repellants, non-stick cookware, and a variety of other industrial and commercial applications.  They are very persistent in the environment and they bind to blood proteins.  Analytical results from this study of U.S. urban rivers indicated that 6 of the 13 target PFCs were detected in fish fillet composites.  Frequency of occurrence was dominated by PFOS, which was detected in 76% of all samples.