OBSERVATIONS AND CONSIDERATIONS ON THE FATE, TRANSPORT, AND BIOACCUMULATION OF PFAS IN THE ENVIRONMENT

Environmental fate and transport of the suite of PFAS compounds differs from other known contaminants as: lack of evidence of natural PFAS degradation indicates chemical cycling and partitioning between the atmosphere, biosphere, geosphere, and hydrosphere; PFAS are generally highly mobile in the environment, yet some compounds are subject to competitive sorption mechanisms that are not well understood over the broad class of compounds, and toxicity in ultralow concentrations (lower than any known contaminant) greatly complicates the characterization, delineation, and remediation of PFAS in the environment. This presentation will focus on observations of PFAS cycling within the environment, and provide observations from Michigan that are unique to PFAS as a contaminant including the formation of foams at the air-water interface along streams and lakes, challenges associated with full plume delineation for accurate assessment of contaminated sites and remedial design, and bioaccumulation along aquatic and riverine ecosystems. Past and ongoing collaboration with the Michigan Department of Environment, Great Lakes, and Energy (EGLE) has provided us access to large quantities of characterization data for many different PFAS-contaminated across the state. Multiple site-specific examples for each topic listed above will be presented along with emerging research areas needed to address outstanding knowledge gaps.