While fish continue to be a focus of many monitoring and assessment programs, there is a clear gap in our knowledge regarding the sources and environmental concentrations of per- and polyfluoroalkyl substances (PFAS) and concentrations in fish tissues. The overarching objective of this project is to develop an improved understanding and an effective model for uptake and accumulation of PFAS in several species of freshwater fish to support monitoring, risk assessment, and risk communication efforts related to Department of Defense installations impacted by PFAS.

This project will utilize a technical approach incorporating laboratory, modeling, and field research efforts that will address the overall objective. The first task will incorporate laboratory uptake and depuration studies in three important freshwater fish species (smallmouth bass, bluegill sunfish, channel catfish) exposed to five PFAS under a suite of relevant environmental and energetic conditions. The hypothesis is that PFAS uptake in fish is linked strongly to factors that modify fish physiology and alter PFAS bioavailability.

Subsequently, the investigators will incorporate the data and bioaccumulation parameters into a series of bioaccumulation models from simpler, one-compartment models to more complex biodynamic accumulation models with the goal of developing the most predictive but simplest bioaccumulation model for test species.

Finally, to further vet the bioaccumulation models and to help direct lab and modeling efforts, the project will conduct field studies at two PFAS-impacted sites. The goal of the field studies is to provide real-world data with which to compare and modify, if needed, previous efforts. The investigators will collect fish and invertebrate samples weekly for up to 30 days while collecting surface water and sediment samples every 2-3 days. These data will represent the best-available, real-world PFAS data in aquatic systems with sufficient temporal resolution that will increase the understanding of PFAS media concentrations through ecologically-relevant timescales thus allowing better modeling PFAS uptake by fish.

Collectively, the data and models generated by this project will represent a significant increase in our understanding of the relationship between PFAS concentrations in media and resulting uptake and accumulation in freshwater fish. These data and the suite of models will help to streamline environmental monitoring efforts, will facilitate risk assessment and communication, and will represent a rich data source for additional insights and advances. The expected outcomes will help to ensure military readiness, range sustainability, and public health and environmental protectiveness. (Anticipated Project Completion - 2024)

Brown, A.S., Y. Xiayan, E.R. McKenzie, C.G. Heron, J.A. Field, and C.J. Salice. 2023. Spatial and Temporal Variability of Per- and Polyfluoroalkyl Substances (PFAS) in Environmental Media of a Small Pond: Toward an Improved Understanding of PFAS Bioaccumulation in Fish. Science of the Total Environment, 880: 163149. doi.org/10.1016/j.scitotenv.2023.163149