Spatial and temporal trends of poly‐ and perfluoroalkyl substances in fish fillets and water collected from pool 2 of the Upper Mississippi River

In 2011, poly- and perfluoroalkyl substances (PFASs) were analyzed in surface water and fish fillet samples taken from Pool 2 of the Upper Mississippi River, a 33-mile stretch inclusive of the Minneapolis/St. Paul, Minnesota metropolitan area. Approximately 100 each of bluegill (BGS), freshwater drum (FWD), smallmouth bass (SMB), and white bass (WHB) were sampled within the study area. Surface water samples were also collected from each of the 10 sampling reaches established for the study. Water and fillet samples were analyzed for perfluorinated carboxylic acids (PFCAs) (C4–C12), perfluorinated sulfonic acids (PFSAs) (C4, C6, and C8), and perfluorooctane sulfonamide (FOSA). Perfluorooctane sulfonate (PFOS) was observed with the greatest frequency in fish fillets and ranged from 3.0 to 760 ng/g ww. Mean (geometric) PFOS concentrations in BGS, FWD, SMB and WHB were 20, 28, 29 and 58 ng/g ww, respectively. When compared to fish data collected in 2009, a significant reduction (p < 0.05) in PFOS concentrations was noted. This finding was confirmed based on data from studies conducted in 2012 and 2013. Overall, between 2009 to 2013 PFOS concentrations decreased by 65, 76 and 50% for BGS, FWD and WHB, respectively (44% decrease for SMB from 2009 to 2012). These declines in fish PFOS concentrations are consistent with ongoing efforts to effectively control sources of PFASs to the Mississippi River. This article is protected by copyright. All rights reserved