Relative Acute Toxicity of Three Per- and Polyfluoroalkyl Substances on Nine Species of Larval Amphibians

By Brian J Tornabene, Michael F Chislock, Megan E Gannon, Maria S SepĂșlveda, and Jason T Hoverman
Integr Environ Assess Manag
January 19, 2021
DOI: 10.1002/ieam.4391

Per- and polyfluoroalkyl substances (PFAS) are widespread, persistent environmental pollutants known to elicit a wide range of negative effects on wildlife species. There is scarce information regarding the toxicity of PFAS on amphibians, but amphibians may be highly susceptible because of their permeable skin and dependence on fresh water. Acute toxicity studies are a first step towards understanding responses to PFAS exposure, providing benchmarks for species-specific tolerances, informing ecological risk assessment (ERA), and designing chronic toxicity studies. We conducted standardized 96-h lethal concentration (LC ) toxicity tests for perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) with nine widely-distributed amphibian species native to eastern and central North America. We also conducted LC tests with perfluorohexane sulfonate (PFHxS) for two species and determined whether toxicity of PFOS and PFOA varied between life stages for three species. Acute toxicity varied among PFAS and species and between developmental stages within species. Across all species, toxicity of PFOS was >8× higher than PFOA. Salamanders in the genus Ambystoma were generally more sensitive to PFOS than anurans (frogs and a toad). Toxicity of PFOA was highest for Small-mouthed Salamanders and Gray Tree Frogs and lowest for Jefferson Salamanders, American Bullfrogs, Green Frogs, and Wood Frogs. Although only two species were exposed to PFHxS, survival was lower for Green Frogs than American Bullfrogs. Toxicity of PFAS also varied between developmental stages of larvae. Gray Tree Frogs were more sensitive at later developmental stages and Small-mouthed Salamanders were more sensitive at earlier developmental stages. Our study is one of the first to report species-, developmental stage-, and compound-specific differences in sensitivity to PFAS across a wide range of amphibian species. The benchmarks for toxicity we determined can inform conservation and remediation efforts, guide chronic toxicity studies, and help predict influences on amphibian communities thereby informing future ERAs for PFAS. This article is protected by copyright. All rights reserved.

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