Fish are important aquatic receptors and can be used as indicators of ecological health. There are uncertainties regarding per- and polyfluoroalkyl substances (PFAS) bioaccumulation in fish that complicate prediction and characterization for management efforts. The goal of this project was to improve the understanding of PFAS bioaccumulation in aquatic systems impacted by aqueous film-forming foam use through field studies and bioaccumulation modeling.

To better understand the accumulation of PFAS in aquatic systems, the team conducted field studies at two sites in the Mid-Atlantic: the Navy Rec Pond at the Former Naval Air Station Joint Reserve Base Willow Grove, PA and Air Force Base Creek at Joint Base Andrews, MD. Temperature was assessed on a weekly and seasonal basis, and spatial variability was evaluated within each system. Then, an existing PFAS bioaccumulation model for fish, which was based on a strongly supported bioaccumulation modeling framework, was implemented with gathered field data.

PFAS concentrations varied substantially through time and by location. The greatest changes appeared to occur after rain events which led to large increases in environmental concentrations. PFAS field bioaccumulation factors in fish were relatively consistent with what is reported in the literature. Despite high variability of PFAS in surface water, fish tissue concentrations were stable. Finally, implementation of a PFAS bioaccumulation model showed agreement between predicted and observed concentrations in fish, although additional species-specific parameterizations may further improve model predictions.

This study showed temporal and spatial dynamics with respect to PFAS concentrations in freshwater systems. Importantly, despite occasional spikes in environmental PFAS concentrations, fish tissue concentrations remained relatively constant (i.e., they did not vary as much as environmental concentrations). Bioaccumulation models worked well and predicated five key PFAS within a factor of 10 or less compared to observed concentrations. The successful execution of this research yielded data essential for the development of advanced technologies aimed at enhancing ongoing remediation efforts at PFAS-impacted sites, thereby providing crucial safeguards for warfighters and installation communities. (Project Completion - 2025)

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