Per- and polyfluoroalkyl substances (PFAS) are ubiquitous in the environment. Currently, little is understood about the potential ecological risk posed by these substances particularly in marine environments. The objective of this study is to quantify ecotoxicity and bioaccumulation of select PFAS in model marine and estuarine organisms for derivation of toxicity reference values (TRVs) to support ecological risk assessments and remediation decision-making.

To better inform ecological risk assessments of PFAS in marine systems, acute and chronic toxicity values will be developed using estuarine and marine organisms. The test species to be studied will include model, sensitive benthic (Leptocheirus plumulosus, Eohaustorius estuarius, Neanthes arenaceodentata), epibenthic (Arbacia punctulata, Paleomon pugio, Americamysis bahia, and Crassostrea virginica), and pelagic (Menidia beryllina, Cyprinodon variegatus, and Acartia spp) organisms. The benthic species will be exposed to spiked sediments while epibenthic and pelagic species will be tested in aqueous exposures. Environmentally relevant PFAS will be evaluated. All species will be evaluated in acute toxicity tests and the most sensitive (based on acute endpoints) of the benthic, epibenthic and pelagic species tested will then be evaluated in chronic sublethal tests. Exposure concentrations (i.e., bulk sediment concentrations in sediment exposures and water concentrations in aqueous exposures) and tissue residues in surviving organisms (i.e., in test species with sufficient biomass to enable analysis) will then be measured. From these study results, TRVs will be derived based on both external exposure concentration and internal dose (tissue residue, where applicable) and measures of bioavailability will be calculated (i.e., bioconcentration factors for aqueous exposures and bioaccumulation factors for sediment exposures).

In the absence of information, uncertainty is addressed through conservative assumptions that may lead to costly and potentially unwarranted management actions. This study will address critical data gaps required for accurate risk characterization of PFAS prevalent in marine systems and thereby enable better informed and more cost-effective risk management decisions. This project will be leveraged with current U. S. Army Corps of Engineers funded research focused on bioavailability and toxicity of sediment associated PFAS in marine and freshwater systems. Additional leveraging will occur through use of data in parametrization of advanced computational models for rapid risk characterization of PFAS that are currently in development under the DoD Advanced Research for the Advancement of Science and Technology Priorities program. (Anticipated Project Completion - 2025)