| Autor: |
Nickerson A; Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401, United States., Rodowa AE; Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, United States., Adamson DT; GSI Environmental Inc., 2211 Norfolk Suite 1000, Houston, Texas 77098, United States., Field JA; Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, United States., Kulkarni PR; GSI Environmental Inc., 2211 Norfolk Suite 1000, Houston, Texas 77098, United States., Kornuc JJ; NAVFAC EXWC, 1100 23rd Avenue, Port Hueneme, California 93041, United States., Higgins CP; Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401, United States. |
| Abstrakt: |
Soil and groundwater from an aqueous film-forming foam (AFFF)-impacted site were sampled at high resolution ( n = 105 for soil, n = 58 for groundwater) and analyzed for an extensive list of anionic, zwitterionic, and cationic poly- and perfluoroalkyl substances (PFASs). Spatial trends for perfluoroalkyl acids and many precursors enabled a better understanding of PFAS composition, transport, and transformation. All PFASs without analytical standards were semi-quantified. Summed PFAS and individual PFAS concentrations were often higher at depth than near the surface in soil and groundwater. Zwitterionic and cationic compounds composed a majority of the total PFAS mass (up to 97%) in firefighter training area (FTA) soil. Composition of PFAS class, chain length, and structural isomers changed with depth and distance from the FTA, suggesting in situ transformation and differential transport. The percentage of branched perfluorooctane sulfonate increased with depth, consistent with differential isomeric transport. However, linear perfluorooctanoic acid (PFOA) was enriched, suggesting fluorotelomer precursor transformation to linear PFOA. Perfluorohexane sulfonamide, a potential transformation product of sulfonamide-based PFASs, was present at high concentrations (maximum 448 ng/g in soil, 3.4 mg/L in groundwater). Precursor compounds may create long-term sources of perfluoroalkyl acids, although many pathways remain unknown; precursor analysis is critical for PFAS fate and transport understanding. |
