Marine ecotoxicity evaluation of 10 per- and poly-fluoroalkyl acids using three USEPA short-term chronic bioassays

Effects data for per- and poly-fluoroalkyl substances (PFAS) for marine aquatic life are lacking, limiting the assessment of site-specific ecological risks in marine ecosystems and development of marine water quality criteria. In this study, the toxicity of 10 PFAS (PFBA, PFHxA, PFOA, PFDA, PFBS, PFHxS, PFOS, PFDS, 6:2 FTS, and 8:2 FTS) were evaluated with three standard marine toxicity testing species: Mediterranean mussel (Mytilus galloprovincialis); purple sea urchin (Strongylocentrotus purpuratus); and giant kelp (Macrocystis pyrifera). Many tests failed to elicit responses exceeding 50 % adverse effect levels, despite approaching solubility limits. EC₅₀ values were able to be derived in only 43 % of the toxicity tests, and were generally above 1 mg/L, except for PFOS and PFDA based on the most sensitive of the three species (S. purpuratus and M. galloprovincialis), with EC₅₀s in the approximate 0.1 to 1 mg/L range. M. pyrifera, the macroalgae, was less sensitive than either invertebrate species. EC₅₀ values for all three species decreased with perfluoroalkyl carbon chain length, as increasing toxicity was observed in longer chained compounds, and a statistically significant relationship between chain length and EC₅₀ was detected for M. galloprovincialis. A number of other toxicological metrics (NOECs, LOECs, EC₁₀s, and EC₂₀s) were also generated. NOECs for sublethal endpoints were in the 0.01 to 100 mg/L range and were orders of magnitude higher than environmentally relevant concentrations. Based on the results in this study, adverse effects on these species and endpoints would not be expected to occur in the PFAS-impacted marine environment.