Wes Flynn is a Postdoctoral Scholar in Natural Resources at Purdue University. He is working with Drs. Linda Lee, Jason Hoverman, and Maria Sepulveda on projects funded by SERDP and Michigan DNR to evaluate the effects of PFAS on aquatic systems contaminated with aqueous film-forming foams (AFFFs). His current research integrates ecotoxicology, disease ecology, and ecosystem ecology to assess the impacts of PFAS on wetland ecosystems, with a focus on amphibians. This work seeks to bridge data gaps between environmental PFAS exposure and laboratory toxicology studies.
Environmentally Relevant Exposures to PFAS Suggest Laboratory Studies Could Underestimate Risk to Aquatic Organisms
Per-/polyfluoroalkyl substances (PFAS) are a class of chemicals that are of increasing concern for both human and wildlife health. The unique features of these chemicals, including high water solubility, persistence in the environment, and the ability to disrupt endocrine function, create unique challenges to assessing the risk they pose wildlife. These challenges are further compounded by a disconnect between how toxicity studies are often conducted and how exposures occur in the environment. For aquatic organisms, environmental PFAS exposures occur at low concentrations via multiple exposure routes over long periods of time. However, toxicity studies typically involve acute exposures to high PFAS concentrations via a single exposure route. To begin bridging this knowledge gap, we compared data collected from a PFAS-contaminated wetland to an experimental study designed to simulate environmental PFAS-exposure on larval amphibians. Levels of PFAS in water, sediments, and tadpoles in our mesocosm study were within the range found at the contaminated site; demonstrating our approach effectively simulated environmental exposure conditions. By comparing the results of our mesocosm study to those from standard laboratory toxicity studies we found that PFOS can delay development at water concentrations as low as 60 ppt. Our results suggest that aquatic PFAS levels found at AFFF-sites could adversely affect larval development of amphibians. Future research replicating this approach and incorporating the multiple PFAS chemicals that generally co-occur in the environment, ecologically relevant endpoints, and native species will allow us to better assess the ecological risk PFAS pose to wildlife.