A Framework for Assessing Bioaccumulation and Exposure Risks of Per- and Polyfluoroalkyl Substances in Threatened and Endangered Species on Aqueous Film Forming Foam (AFFF)-Impacted Sites

This project generally follows conventional methods employed for ecological risk assessment, including exposure characterization, effects characterization and risk estimation. In particular, the approach utilizes a combination of field-based measurements and bioaccumulation modeling to evaluate exposure in T and E species. Toxicity reference values (TRVs) are derived using the available toxicity data, along with species-sensitivity distributions (SSDs) and resulting 5th percentile of the hazardous concentration levels (HC5s) or application of uncertainty factors to the lowest observed toxicity values.