Per- and Polyfluoroalkyl Substances (PFAS) and Metals in Wild and Farmed Oysters of a Minimally Developed Coastal Region in the Southeastern United States

Abstract

We investigated the presence of metals (Zn, Cu, Cd, Pb, and Hg) and per- and polyfluoroalkyl substances (PFAS) in eastern oysters (Crassostrea virginica) from the White Oak River Basin (WORB), a sparsely populated coastal watershed in North Carolina, USA. We compared wild and farmed oysters to evaluate whether their positions within the water column influenced contaminant accumulation. Consumption risk was also assessed based on meal size, toxicological guidance values, and individual physiological parameters. Metals and PFAS were consistently detected in oysters across the WORB but generally occurred at low concentrations. Spatial patterns suggest that metal concentrations may be largely influenced by geogenic or background sources, whereas PFAS contamination may originate primarily from nonpoint sources. Despite low contaminant concentrations, estimated consumption risk varied among analytes, with substantial uncertainty associated with current toxicological and regulatory guidance. These findings improve understanding of contaminant fate and bioaccumulation in a coastal system with limited anthropogenic land use and provide a framework for evaluating bivalve consumption risk that incorporates contaminant-specific toxicity and individual physiological characteristics.