A Baseline Assessment of Spatial and Temporal Trends of Perfluorinated Alkyl Substances in the Apalachicola River and Bay

Poly- and perfluorinated alkyl substances (PFAS) are categorized as emerging environmental contaminants of concern due to their toxicity, persistence, and ability to bioaccumulate once deposited into the environment. Represented in the large PFAS group is fully fluorinated compounds known commonly as perfluorinated organic compounds (PFCs), none of which occur naturally. The aim of this research is to assess the need for inclusion of PFCs surveillance in current policy and management strategies that strive to maintain the ecological health of the lower Apalachicola River and estuary in Northwest Florida. Apalachicola Bay is a major estuarine, commercial, and recreational seafood resource at the endpoint of the Apalachicola-Chattahoochee-Flint River Basin in the Gulf of Mexico.

Investigation of the occurrence, distribution and bioavailability of PFCs in the lower Apalachicola River and estuary was accomplished utilizing the passive in-situ polar organic integrative sampler (POCIS) in concert with historical (1986-1987 through 2006-2007) biota and sediment samples from NOAA's Mussel Watch program. PFCs were detected in archived oyster and sediment samples and in the water column via passive sampling. Concentrations ranged from < LOD to 4.7ng/g wet weight, oysters; <LOD to 2.5ng/g, wet weight sediment; and 0.3-59ng/L, water. PFCs concentrations were not statistically different (p > 0.05) in oyster and sediment samples among sampling sites. Temporally, there was a significant increase in PFCs concentrations in oysters from 1986-1987 through 2002-2003; however concentrations dramatically decrease for the remaining sampling years. No significant temporal trend was observed for the sediment samples. Spatially, PFCs water concentrations were significantly different (p < 0.01) with upriver samples having higher concentrations than samples from the bay. The results of this study provide a baseline assessment of the lower Apalachicola River and estuary and may allow prediction of potential impacts in this ecosystem.