Facemasks are important tools for fighting against disease spread, including Covid-19 and its variants, and some may be treated with per-and polyfluoroalkyl substances (PFAS). Nine facemasks over a range of prices were analyzed for total fluorine and PFAS. The PFAS compositions of the masks were then used to estimate exposure and the mass of PFAS discharged to landfill leachate. Fluorine from PFAS accounted only for a small fraction of total fluorine. Homologous series of linear perfluoroalkyl carboxylates and the 6:2 fluorotelomer alcohol indicated a fluorotelomer origin. Inhalation was estimated to be the dominant exposure route (40%−50%), followed by incidental ingestion (15%− 40%) and dermal (11%−20%). Exposure and risk estimates were higher for children than adults, and high physical activity substantially increased inhalation exposure. These preliminary findings indicate that wearing masks treated with high levels of PFAS for extended periods of time can be a notable source of exposure and have the potential to pose a health risk. Despite modeled annual disposal of ∼29−91 billion masks, and an assuming 100% leaching of individual PFAS into landfill leachate, mask disposal would contribute only an additional 6% of annual PFAS mass loads and less than 11 kg of PFAS discharged to U.S. wastewater.

Landfill leachates possess a countless number of chemical classes of potential environmental and human concern, including per- and polyfluoroalkyl substances (PFAS). While detection and biodegradation studies of PFAS in leachates have been conducted previously, the degradation of precursors of perfluoroalkyl acids (PFAAs) in landfill leachates with oxidative technologies has not been addressed. Thus, information regarding the oxidative transformations of PFAA precursors typically present in leachates is lacking. Target and suspect PFAS were identified in a landfill leachate, and their concentrations during electrochemical treatment were quantified over time. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF) measurements of the leachate showed a total PFAS concentration of 157 ± 10 nmol/L that included 53 PFAS and 19 different classes. Multiple PFAS are reported for the first time in landfill leachates. The molar composition of the leachate was comprised of 33% PFAAs, 7% electrochemical fluorination (ECF) precursors, and 60% fluorotelomer (FT) precursors. Further analysis with total oxidizable precursor (TOP) assay revealed an additional concentration of precursors that was not identified with LC-QToF. The evaluation of the intermediate and final products generated during the electrochemical treatment showed evidence of known electrochemical degradation pathways. However, this is the first study to have more evidence for electrochemical pathways in landfill leachates. In brief, sulfonamide-based precursors and fluorotelomer-based precursors were electrochemically transformed into perfluoroalkyl carboxylic acids (PFCAs) during treatment of the leachate.

Per-and polyfluoroalkyl substances (PFAS) and non-aqueous phase liquids (NAPLs) co-occur at sites where aqueous film forming foams (AFFFs) were used as part of firefighter training exercises or in response to emergencies (e.g., crashes). Till date, there are no data on PFAS in field-collected, light NAPLs (LNAPLs) recovered from groundwater wells on US military bases. Analytical methods were developed for target and suspect nonvolatile (anionic) and volatile (neutral) PFAS in field-collected LNAPLs. The validated methods were demonstrated on 17 LNAPL samples collected from the subsurface at five military installations with known AFFF impacts and where LNAPL releases date 10−70 years ago. Target and suspect anionic PFAS associated with AFFF of either electrochemical fluorination or fluorotelomerization origin were quantified and semi-quantified, respectively, in 11 LNAPLs. Perfluorooctane sulfonate (PFOS) occurred at the highest frequency, ranging from 110 to 11,100 ng/L. As a class, perfluoroalkyl sulfonamides occur at a frequency similar to that of PFOS, but at higher concentrations, with the C6 homolog ranging up to 67,500 ng/L. Only one LNAPL had quantifiable neutral PFAS (6:2 fluorotelomer alcohol), indicating potential biotransformation and/or volatilization. Residual LNAPLs at AFFF-impacted field sites may represent an undetected reservoir of PFAS that must be considered when designing remedial actions.

When performing basic and translational laboratory studies with aquatic organisms, particularly for bioaccumulation, toxicity, or biotransformation experiments, it is imperative to control the route and dose of exposure. Contamination of feed and the organisms prior to study could alter the results of an experiment. Furthermore, if organisms not exposed in the lab are used for quality assurance/quality control, then blank levels, method detection limits, and limits of quantitation can be affected. In an effort to determine the magnitude of this potential issue for exposure studies involving Pimephales promelas, we analyzed a suite of 24 per-and polyfluoroalkyl substances (PFAS) in four types of feed from three different companies and in organisms from five aquaculture facilities. Contamination with PFAS was found in all types of materials and organisms from all aquaculture farms. The most frequently detected PFAS in fish feed and aquaculture fathead minnows were perfluorocarboxylic acids and perfluorooctane sulfonate (PFOS). Concentrations of total and individual PFAS in feed ranged from nondetect to 76 ng/g and from nondetect to 60 ng/g, respectively. Fathead minnows were contaminated with PFOS and perfluorohexane sulfonate as well as several perflourocarboxylic acids. Concentrations of total and individual PFAS ranged from 1.4 to 351 ng/g and from nondetect to 328 ng/g, respectively. The PFOS measured in food was primarily the linear isomer, consistent with greater bioaccumulation of that isomer in organisms raised as fish food. Future studies are necessary to define the extent of PFAS contamination in aquatic culture facilities and aquaculture production operations.