“Development of PFAS Toxicity Reference Values in Amphibians for use in Ecological Risk Assessments of AFFF-Contaminated Sites” by Dr. Marisol Sepulveda (Project Webpage)

The primary goal of this project was to develop per- and polyfluoroalkyl substances (PFAS) toxicity reference values (TRVs) for amphibians. TRVs are needed to evaluate risk for amphibians native to the U.S., including northern leopard frogs, bullfrogs, American toads, and tiger salamanders, in areas contaminated by aqueous film forming foam (AFFF) and PFAS mixtures, including some Department of Defense (DoD) lands. Larvae and juveniles were exposed to PFAS of different chain length and functional groups. Results showed that PFAS uptake and elimination rates are fast (48 hours to reach steady state). This is the fastest accumulation rate reported for a developing vertebrate. Effects on growth and development were shown to be dependent on PFAS, species, life-stage, and exposure-route. We found that although PFOS bioaccumulated two orders of magnitude more than some other PFAS, it is not necessarily more toxic. Altered growth and development were observed at 10 parts per billion (ppb), the lowest concentration tested. In addition to the above results, this presentation covered testing PFAS mixtures recreated using data from AFFF-impacted sites under semi-natural and laboratory conditions.

“Guidance for Assessing the Ecological Risks of Threatened and Endangered Species at Aqueous Film Forming Foam (AFFF)-Impacted Sites” by Dr. Jason Conder (Project Webpage)

This project supported SERDP’s efforts to maintain DoD execution of mission-related activities by providing effective, science-based guidance for promoting the recovery of understory plant communities. Our work combined intensive long-term monitoring of plant populations with field-based experiments deployed over three separate installations. We tracked 25 plant species by conducting long-term sampling at 192 plots from 18 sites at Fort Bragg in North Carolina, 12 sites at Fort Stewart in Georgia, and 18 sites at Savannah River Site in South Carolina. We evaluated whether (1) management activities (e.g., seed additions, prescribed fire, tree thinning) could be used to maximize plant population and community recovery, (2) plant populations persisted as self-sustaining populations for many years after recovery was initiated, and (3) management activities could maximize the likelihood that populations would spread once established, resulting in self-propagating recovery efforts. Our long-term data provided a powerful means to evaluate how seasonal climatic variation affect plant populations. The presentation described the management activities that maximize the establishment, persistence, and spread of plants in longleaf pine ecosystems, and will highlight how seasonal climatic variation may play a critical, yet unappreciated, role in guiding recovery of plant communities on DoD lands.

Dr. Maria S. (Marisol) Sepúlveda is a professor of ecotoxicology and aquatic animal health in the Department of Forestry and Environmental Sciences at Purdue University. Her research focuses on understanding the effects and toxicity mechanisms of emerging contaminants. Her laboratory utilizes several models, including cells, invertebrates, fish, and amphibians, to evaluate ecologically relevant effects at the whole animal, sub-cellular, and molecular scale. She has published over 150 peer-reviewed publications, authored 9 books chapters, and presented her research in multiple invited lectures and presentations at national and international conferences. Marisol earned her veterinary medicine degree from Universidad de Chile in Santiago, and her master’s and doctoral degrees from the University of Florida in wildlife ecology and toxicology, respectively.

Dr. Jason Conder is a principal at Geosyntec Consultants in Huntington Beach, California. He has more than 15 years of experience in environmental toxicology, ecological and human health risk assessment, bioaccumulation and bioavailability of environmental contaminants, environmental chemistry, environmental monitoring technology, and statistics. Jason has produced several product- and site-specific fate and risk assessments on PFAS. In addition, he has co-authored review articles on PFAS use, fate, terminology, and bioaccumulation, as well as two PFAS documents for the DoD, including a Frequently Asked Questions document and a guidance document for ecological risk assessments. He has published more than 20 peer-reviewed journal articles in Environmental Toxicology and Chemistry and presented at numerous international conferences. He has a bachelor’s degree in wildlife ecology and a master’s degree in zoology from Oklahoma State University, and a doctoral degree in environmental science from the University of North Texas.