The objective of this study is to evaluate the exposure of populations of water-associated bird species to per- and polyfluoroalkyl substances (PFAS). This project is a collaboration between Jacobs, Oregon State University, and the Biodiversity Research Institute (BRI) that is leveraging archived biota sample remainders to address data gaps at a lower cost. Ultimately, the research will field assess if risk modeling with laboratory-derived toxicity reference values (TRVs) aligns with field monitoring studies. It will also assess anthropogenic background PFAS concentrations for future monitoring. The study builds upon the SERDP-funded project ER21-3464, led by Christine Custer, and will provide some insight to ER22-3333, led by Jean Zodrow.

The proposed approach uses two distinct technical tasks to assess PFAS toxicity to birds from analyzing PFAS in eggs of up to four species of aquatic birds. To date eggs have been analyzed for common loon (Gavia immer), osprey (Pandion haliaetus), and double crested cormorant (Nannopterum auritum). Egg samples will be from species that are: (1) high on the food chain, (2) commonly used in food web modeling for ecological risk assessments at contaminated sites or (3) forage within a small range during nesting. Homogenized whole egg PFAS concentrations will be compared to laboratory-determined egg PFAS TRVs. Risk conclusions determined using laboratory-determined PFAS TRVs will be compared to field monitoring conclusions to provide a field demonstration that decisions being made using the TRVs are sensible.

The project will aid the understanding of PFAS presence and transport within aquatic ecosystems and re-emphasize the ecological health of local bird populations over laboratory/model predicted health. Results will aid risk assessments and provide insights for Department of Defense (DoD) facilities. The research is expected to show that eggs of selected bird species are an effective method of monitoring exposure and assessing the potential adverse population-level effects on birds. Results from this study will be transferable to other DoD locations where PFAS are expected to be present. (Anticipated Project Completion – 2026)