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A High-Resolution Reconstruction of PFAS Deposition in an Urban River using a Radiometrically Dated Sediment Core
Citation:
Cashman, M., A. Robuck, T. Boving, AND M. Cantwell. A High-Resolution Reconstruction of PFAS Deposition in an Urban River using a Radiometrically Dated Sediment Core. Society of Environmental Toxicology and Chemistry North America, 42nd Annual Meeting, NA, Virtual, November 14 - 18, 2021.
Impact/Purpose:
Per- and polyfluoroalkyl substances (PFAS) are fluorinated, man-made chemicals that pose a risk to the environment. In this study, a radiometrically dated sediment core is analyzed for PFAS compounds to develop a picture of when they were used in manufacturing. This core was taken from an urban river in Rhode Island, USA that is home to former facilities that may have used PFAS compounds. PFAS analysis coupled with radiometric dating provides a history of PFAS discharge to the river. These data and methods are helpful to the environmental managers and the public to identify past and present sources of PFAS contamination.
Description:
The use of per- and polyfluoroalkyl substances (PFAS) in industrial applications predates accessible analytical techniques for their identification in environmental matrices. Dated sediment cores offer a mechanism to determine past PFAS deposition and provides a better understanding of the fate of this complex class of contaminants in aquatic environments. In this study, a sediment core was collected from a dammed section of an urban river in Rhode Island, USA. The coring location was chosen for its proximity to former manufacturing facilities suspected to use PFAS. The core was radiometrically dated using 137Cs and 210Pb and analyzed for 24 PFAS compounds using a targeted analytical method. A modified Total Oxidizable Precursor (TOP) assay was then performed to identify presence of PFAS precursors. Suspect and non-targeted analysis was performed to identify additional PFAS missed in targeted analysis. Initial sediment concentrations showed temporal trends of PFAS preserved within the sediment record ranging from <1-50 ng/g sediment. These data identify legacy PFAS compounds previously used in manufacturing processes over several decades, particularly long-chain perfluorinated carboxylic acids (PFCAs). This type of investigation provides a window into the behavior of PFAS once they enter the sedimentary environment.
