Vermont-wide Assessment of Anthropogenic Background Concentrations of Perfluoroalkyl Substances in Surface Soils

By Wenyu Zhu, Kamruzzaman Khan, Harrison Roakes, Elliot Maker, Kristen L. Underwood, Stephen Zemba, and Appala Raju Badireddy
J. Hazard. Mater.
June 25, 2022
DOI: 10.1016/j.jhazmat.2022.129479

Shallow surface soils from 66 suburban sampling locations across Vermont were analyzed for 17 different perfluoroalkyl acids (PFAA). PFAA were detected in all 66 surface soils, with a total concentration of PFAA ranging from 540 to 36,000 ng/kg dry soil weight (dw). Despite the complexity of site-specific factors, some general trends and correlations in PFAS concentrations were observed. For instance, perfluoro-1-octanesulfonate (PFOS) dominated in all soil samples while nine other PFAS, including perfluoro-n-nonanoic acid, perfluoro-n-octanoic acid, perfluoro-n-hexanoic acid, perfluoro-n-heptanoic acid, perfluoro-n-decanoic acid, perfluoro-n-undecanoic acid, perfluoro-1-butanesulfonate, and perfluoro-1-hexanesulfonate (PFNA, PFOA, PFHxA, PFHpA, PFDA, PFUnDA, PFBS, and PFHxS, respectively), were identified at more than 50% of the locations. Perfluoroalkyl carboxylic acids (PFCA) showed a positive correlation with total organic carbon, whereas no clear correlation was observed for perfluoroalkyl sulfonate acids (PFSA). In addition, variations in geographical distributions of PFAS were observed, with relatively higher total PFAA in northern regions when compared to southern Vermont. Moreover, PFHxA, PFNA, PFDA, PFUnDA, PFOS, and total PFAA were positively correlated to land-use types in northern Vermont. These results are useful for understanding unique behaviors of PFCA vs. PFSA in geospatially distributed surface soils and for providing anthropogenic background data for setting PFAS cleanup standards for surface soils.

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