Environmental Fate of Cl-PFPECAs: Accumulation of Novel and Legacy Perfluoroalkyl Compounds in Real-World Vegetation and Subsoils

• Published in: Environmental science & technology 2023-06, Vol.57 (24), p.8994-9004
• Main Authors: Davis, Mary J. B., Evich, Marina G., Goodrow, Sandra M., Washington, John W.
• Format: Article
• Language: English
• Subjects: Accumulation; Alkanesulfonic Acids; Aquatic plants; Fluorination; Fluorocarbons - analysis; Food Chain; Food chains; Food webs; Humans; Molecular chains; Molecular weight; Occurrence, Fate, and Transport of Aquatic and Terrestrial Contaminants; Perfluoroalkyl & polyfluoroalkyl substances; Soil; Soil surfaces; Soil water; Soils; Subsoils; Vegetation; Water Pollutants, Chemical - analysis; Wildlife
• ISSN: 0013-936X; 1520-5851; 1520-5851
• DOI: 10.1021/acs.est.3c00665

Per- and polyfluoroalkyl substances (PFAS) are globally distributed and potentially toxic compounds. We report accumulation of chloroperfluoropolyethercarboxylates (Cl-PFPECAs) and perfluorocarboxylates (PFCAs) in vegetation and subsoils in New Jersey. Lower molecular weight Cl-PFPECAs, containing 7–10 fluorinated carbons, and PFCAs containing 3–6 fluorinated carbons were enriched in vegetation relative to surface soils. Subsoils were dominated by lower molecular weight Cl-PFPECAs, a divergence from surface soils. Contrastingly, PFCA homologue profiles in subsoils were similar to surface soils, likely reflecting temporal-use patterns. Accumulation factors (AFs) for vegetation and subsoils decreased with increasing CF2, 6–13 for vegetation and 8–13 in subsoils. In vegetation, for PFCAs having CF2 = 3–6, AFs diminished with increasing CF2 as a more sensitive function than for longer chains. Considering that PFAS manufacturing has transitioned from long-chain chemistry to short-chain, this elevated vegetative accumulation of short-chain PFAS suggests the potential for unanticipated PFAS exposure levels globally in human and/or wildlife populations. This inverse relationship between AFs and CF2-count in terrestrial vegetation is opposite the positive relationship reported in aquatic vegetation suggesting aquatic food webs may be preferentially enriched in long-chain PFAS. AFs normalized to soil–water concentrations increased with chain length for CF2 = 6–13 in vegetation but remained inversely related to chain length for CF2 = 3–6, reflecting a fundamental change in vegetation affinity for short chains compared to long.