Patterns of Occurrence of PFAS Compounds in Fresh Water Fish from Major U.S. Rivers

One of the most prominent and problematic qualities of Perfluoro-Alkyl Substances (PFAS) is the number and diversity of identified compounds. The occurrence of PFAS in fish, however, is limited by its decreasing solubility with increasing chain length and is generally limited to the longer chain (C-7 to C-14) compounds. PFOS was detected in 346/349 fish fillet samples from major U.S. rivers studied by the U.S. EPA in the 2013-2014 National Rivers and Streams Assessment. Other PFAS compounds, (PFUnA, PFDA, and PFDoA), were also consistently detected in a highly repeatable pattern. 148/322 samples were found to include PFOS, PFUnA, PFDA, and PFDoA with or without other PFAS. Other identified groups of compounds included these compounds with 1) PFNA (93 samples), 2) PFOSA (45 samples), or 3) both PFNA and PFOSA (36 samples). This project uses adopted nomenclature for these common groupings of PFAS in fish tissue to facilitate an assessment of health risks associated with exposure to fishers and their families from consuming fish containing these compounds in combination. Such an assessment has been impeded by a lack of information on their toxicological characteristics relative to human consumption.Ope