Per- and polyfluoroalkyl substances (PFASs) are highly mobile in the saturated subsurface, yet aqueous film-forming foam (AFFF)-impacted source zones appear to be long lasting PFAS reservoirs. This study examined the release of over one hundred anionic and zwitterionic PFASs from two AFFF-impacted surface soils under saturated conditions with packed soil columns. Perfluoroalkyl acids (PFAAs) were released more rapidly than their polyfluorinated precursors, while anionic PFASs that were present in partially uncharged states were released more slowly than PFASs that were present entirely as anions, as were zwitterionic PFASs with terminal cationic functional groups when compared with analogous zwitterions with only anionic terminal groups. Nonideal transport was observed in both per- and polyfluorinated classes, as soil column effluent concentrations of slowly released PFASs increased by up to 107-fold with sustained artificial groundwater flow. A flow-interruption experiment suggested the influence of rate-limited desorption on diverse PFAS classes, including PFAAs with as few as four perfluorinated carbons. These results suggest that during infiltration the slow, rate-limited desorption of anionic and zwitterionic PFAA precursors may result in these compounds comprising an increasingly large fraction of the remaining PFASs in AFFF-impacted surface soils.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.est.1c02871 | DOI Listing |
J Am Chem Soc
January 2025
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Defluorination reactions are increasingly vital due to the extensive use of organofluorine compounds with robust carbon-fluorine (C-F) bonds; particularly, the efficient defluorination of widespread and persistent per- and polyfluoroalkyl substances under mild conditions is crucial due to their accumulation in the environment and human body. Herein, we demonstrate that surface-modified silicate of pronounced proton affinity can confine active hydrogen (•H) onto nanoscale zerovalent iron (nZVI) by withdrawing electrons from nZVI to react with bound protons, generating confined active hydrogen (•H) for efficient defluorination under ambient conditions. The exposed silicon cation (Si) of silicate functions as a Lewis acid site to activate the C-F bond by forming Si.
View Article and Find Full Text PDFEnviron Health Perspect
January 2025
Silent Spring Institute, Newton, Massachusetts, USA.
Background: Unregulated contaminants in drinking water, such as per- and polyfluoroalkyl substances (PFAS), can contribute to cumulative health risks, particularly in overburdened and less-advantaged communities. To our knowledge, there has been no nationwide assessment of socioeconomic disparities in exposures to unregulated contaminants in drinking water.
Objective: The goals of this study were to identify determinants of unregulated contaminant detection among US public water systems (PWSs) and evaluate disparities related to race, ethnicity, and socioeconomic status.
J Mass Spectrom
February 2025
FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, North Carolina, USA.
Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a class of emerging contaminants that have been in use industrially since the 1940s. Their long-term and extensive commercial use has led to their ubiquitous presence in the environment. The ability to measure the bioconcentration and distribution of PFAS in the tissue of aquatic organisms helps elucidate the persistence of PFAS as well as environmental impacts.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Despite advancements in high-resolution screening techniques, the identification of novel perfluoroalkyl and polyfluoroalkyl substances (PFAS) remains challenging without prior structural information. In view of this, we proposed and implemented a new data-driven algorithm to calculate spectral similarity among PFAS, facilitating the generation of molecular networks to screen for unknown compounds. Using this approach, 81 PFAS across 12 distinct classes were identified in soil samples collected near an industrial park in Shandong Province, China, including the first reported occurrence of 12 iodine-substituted PFAS.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
The deleterious health implications of perfluoroalkyl and polyfluoroalkyl substances (PFAS) are widely recognized. Females, in contrast to males, exhibit unique pathways for PFAS exposure and excretion, leading to complex health outcomes. The health status of females is largely influenced by hormone-related processes.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!