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Contaminants in Fish from U.S. Rivers: Probability-Based National Assessments
Citation:
Stahl, L., B. Snyder, H. McCarty, T. Kincaid, A. Olsen, T. Cohen, AND J. Healey. Contaminants in Fish from U.S. Rivers: Probability-Based National Assessments. SCIENCE OF THE TOTAL ENVIRONMENT. Elsevier BV, AMSTERDAM, Netherlands, 861(25):160557, (2023). https://doi.org/10.1016/j.scitotenv.2022.160557
Impact/Purpose:
This study documents the presence of fish tissue contaminants in rivers (≥5th order in size) in the conterminous U.S. The study documents the status in 2013-14 and 2018-19 and investigates whether fillet concentrations may impact human health. All fillet tissue samples contained detectable levels of mercury and PCBs. PFAS were detected in 99.7% and 95.2% of the fillet samples from fish collected in 2013-14 and 2018-19, respectively. This information may be used to document the current status and change in that status from the prior 5-year period.
Description:
Most existing fish consumption advisories in the United States (U.S.) have been issued for mercury and polychlorinated biphenyl (PCB) contamination, and recently per- and polyfluoroalkyl substances (PFAS) have emerged as a contaminant group warranting fish consumption advice. In 2008, the U.S. Environmental Protection Agency (EPA) developed an unequal probability survey design to allow a comprehensive characterization of mercury, PCB, and PFAS contamination in fish from U.S. rivers on a national scale. During 2013-2014 and 2018-2019, fish fillet samples were collected from 353 and 290 river sites, respectively, selected randomly from the target population of rivers (≥5th order in size) in the conterminous U.S. This comprised a nationally representative sample with results that were extrapolated to chemical-specific sampled populations of 48,826 to 79,448 river kilometers (km) in 2013-14 and 66,142 river km in 2018-19. The goal was to develop estimates of the national distribution of total mercury, all 209 PCB congeners, and up to 33 PFAS (including perfluorooctane sulfonate or PFOS) in river fish. All fillet tissue samples contained detectable levels of mercury and PCBs. PFAS were detected in 99.7% and 95.2% of the fillet samples from fish collected in 2013-14 and 2018-19, respectively. Fish tissue screening levels applied to national contaminant probability distributions allowed an estimation of the percentage of the sampled population of river lengths that contained fish with fillet concentrations above a level protective of human health. Fish tissue screening level exceedances for an average level of fish consumption ranged from 23.5% to 26.0% for mercury, 17.3% to 51.6% for PCBs, and 0.7% to 9.1% for PFOS.
