Abstract. Drinking water contamination by per- and polyfluoroalkyl substances (PFAS) is widespread near more than 300 United States (U.S.) military bases t
Addressing Urgent Questions for PFAS in the 21st Century
Abstract. Despite decades of research on per- and polyfluoroalkyl substances (PFAS), fundamental obstacles remain to addressing worldwide contamination by
Uptake of Per- and Polyfluoroalkyl Substances by Fish, Mussel, and Passive Samplers in Mobile-Laboratory Exposures Using Groundwater from a Contamination Plume at a Historical Fire Training Area, Cape Cod, Massachusetts
Abstract. Aqueous film-forming foams historically were used during fire training activities on Joint Base Cape Cod, Massachusetts, and created an extensive
Sociodemographic Factors Are Associated with the Abundance of PFAS Sources and Detection in U.S. Community Water Systems
Abstract. Drinking water contaminated by per- and polyfluoroalkyl substances (PFAS) is a widespread public health concern, and exposure–response relationsh
Per- and polyfluoroalkyl substances (PFAS) and total fluorine in fire station dust
Per- and polyfluoroalkyl substances (PFAS) are a class of over 4700 fluorinated compounds used in industry and consumer products. Studies have highlighted the use of aqueous film-forming foams (AFFFs) as an exposure source for firefighters, but little is known about PFAS occurrence inside fire stations, where firefighters spend most of their shifts. In this study, we aimed to characterize PFAS concentrations and sources inside fire stations. We measured 24 PFAS (using LC–MS/MS) and total fluorine (using particle-induced gamma ray emission) in dust from multiple rooms of 15 Massachusetts stations, many of which (60%) no longer use PFAS-containing AFFF at all and the rest of which only use it very rarely. Compared to station living rooms, turnout gear locker rooms had higher dust levels of total fluorine (p < 0.0001) and three PFAS: perfluorohexanoate (PFHxA), perfluoroheptanoate (PFHpA), and perfluorodecanoate (PFDoDA) (p < 0.05). These PFAS were also found on six wipes of station turnout gear. By contrast, the dominant PFAS in living rooms was N-ethyl perfluorooctane sulfonamidoacetic acid (N-MeFOSAA), a precursor to perfluorooctane sulfonate (PFOS) that still persists despite phase-outs almost two decades ago. The Σ24 PFAS accounted for less than 2% of fluorine in dust (n = 39), suggesting the potential presence of unknown PFAS. Turnout gear may be an important PFAS source in stations due to intentional additives and/or contamination from firefighting activities.
A review of the pathways of human exposure to poly- and perfluoroalkyl substances (PFASs) and present understanding of health effects
Here, we review present understanding of sources and trends in human exposure to poly- and perfluoroalkyl substances (PFASs) and epidemiologic evidence for impacts on cancer, immune function, metabolic outcomes, and neurodevelopment. More than 4000 PFASs have been manufactured by humans and hundreds have been detected in environmental samples. Direct exposures due to use in products can be quickly phased out by shifts in chemical production but exposures driven by PFAS accumulation in the ocean and marine food chains and contamination of groundwater persist over long timescales. Serum concentrations of legacy PFASs in humans are declining globally but total exposures to newer PFASs and precursor compounds have not been well characterized. Human exposures to legacy PFASs from seafood and drinking water are stable or increasing in many regions, suggesting observed declines reflect phase-outs in legacy PFAS use in consumer products. Many regions globally are continuing to discover PFAS contaminated sites from aqueous film forming foam (AFFF) use, particularly next to airports and military bases. Exposures from food packaging and indoor environments are uncertain due to a rapidly changing chemical landscape where legacy PFASs have been replaced by diverse precursors and custom molecules that are difficult to detect. Multiple studies find significant associations between PFAS exposure and adverse immune outcomes in children. Dyslipidemia is the strongest metabolic outcome associated with PFAS exposure. Evidence for cancer is limited to manufacturing locations with extremely high exposures and insufficient data are available to characterize impacts of PFAS exposures on neurodevelopment. Preliminary evidence suggests significant health effects associated with exposures to emerging PFASs. Lessons learned from legacy PFASs indicate that limited data should not be used as a justification to delay risk mitigation actions for replacement PFASs.
A Statistical Approach for Identifying Private Wells Susceptible to Perfluoroalkyl Substances (PFAS) Contamination
Abstract. Drinking water concentrations of per- and polyfluoroalkyl substances (PFAS) exceed provisional guidelines for millions of Americans. Data on priv
Uptake of Per- and Polyfluoroalkyl Substances by Fish, Mussel, and Passive Samplers in Mobile Laboratory Exposures using Groundwater from a Contamination Plume at a Historical Fire Training Area, Cape Cod, Massachusetts - Chemical and Biological Data from August to September 2018
This data release presents chemical and biological results from an investigation of the uptake of per- and polyfluoroalkyl substances (PFAS) from groundwater contaminated by fire training activities on Cape Cod, Massachusetts. Exposure experiments were conducted from August 29 to September 21, 2018 using groundwater from a relatively uncontaminated reference site and a fire training area contaminated site. To assess the uptake characteristics of the PFAS mixtures present in the 2 groundwater sources, 21-day mobile laboratory exposure experiments were conducted using fathead minnows (Pimephales promelas), polar organic chemical integrative samplers, and polyethylene tube samplers. Freshwater mussel (Ligumia subrostrata) exposure experiments were conducted for 14 days, beginning on day 7 of the fish and passive sampler exposures. Groundwater samples were collected daily (with a few exceptions). Samples for male fish and passive samplers were collected on days 0, 4, 7, 14, and 21. Samples for female fish were collected on days 0, 7, 14, and 21. The 14 day mussel exposures began on day 7 of the fish and passive sampler exposures, and mussel samples were collected on days 7, 11, 14, and 21. Groundwater site locations and well characteristics are presented in Table 1. Information on the various PFAS and co-occurring contaminants measured in the different media are presented in Table 2. Quality assurance results for PFAS analysis of the different media are presented in Table 3. Results for PFAS in groundwater are presented in Table 4. Results for co-occurring contaminants in groundwater are presented in Table 5. Results for fish biomarkers are presented in Table 6. Results for PFAS in male and female fish tissue are presented in Table 7. Results for PFAS in mussel tissue are presented in Table 8. Results for PFAS in polar organic chemical integrative samplers are presented in Table 9. Results for PFAS in polyethylene tube samplers are presented in Table 10.
Characterization of the Potential Long-Term Impact from Sedimentary PFAS at a Historically Contaminated Textile Waste Site
Abstract. Per- and polyfluoroalkyl substances (PFAS) are pervasive pollutants at historically contaminated sites throughout the United States and beyond. T
Characterization of the Potential Long-Term Impact from Sedimentary PFAS at a Historically Contaminated Textile Waste Site
Abstract. Per- and polyfluoroalkyl substances (PFAS) are pervasive pollutants at historically contaminated sites throughout the United States and beyond. T
Isolating the AFFF Signature in Coastal Watersheds Using Oxidizable PFAS Precursors and Unexplained Organofluorine
Abstract. Water supplies for millions of U.S. individuals exceed maximum contaminant levels for per- and polyfluoroalkyl substances (PFAS). Contemporary an
Stability of Per- and Polyfluoroalkyl Substances in Solvents Relevant to Environmental and Toxicological Analysis
Abstract. Per- and polyfluoroalkyl substances (PFASs) are widely used anthropogenic chemicals. For environmental and toxicological analysis, it is importan
Tap Water Contributions to Plasma Concentrations of Poly- and Perfluoroalkyl Substances (PFAS) in a Nationwide Prospective Cohort of U.S. Women
Abstract Background: Between 2013 and 2015, concentrations of poly- and perfluoroalkyl substances (PFAS) in public drinking water supplies serving at least six million individuals exceeded the level set forth in the health advisory established by the U.S. Environmental Protection Agency. Other than data reported for contaminated sites, no systematic or prospective data exist on the relative source contribution (RSC) of drinking water to human PFAS exposures. Objectives: This study estimates the RSC of tap water to overall PFAS exposure among members of the general U.S. population. Methods: We measured concentrations of 15 PFAS in home tap water samples collected in 1989–1990 from 225 participants in a nationwide prospective cohort of U.S. women: the Nurses’ Health Study (NHS). We used a one-compartment toxicokinetic model to estimate plasma concentrations corresponding to tap water intake of PFAS. We compared modeled results with measured plasma PFAS concentrations among a subset of 110 NHS participants. Results: Tap water perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA) were statistically significant predictors of plasma concentrations among individuals who consumed ≥8 cups of tap water per day. Modeled median contributions of tap water to measured plasma concentrations were: PFOA 12% (95% probability interval 11%–14%), PFNA 13% (8.7%–21%), linear perfluorooctanesulfonic acid (nPFOS) 2.2% (2.0%–2.5%), branched perfluorooctanesulfonic acid (brPFOS) 3.0% (2.5%–3.2%), and perfluorohexanesulfonic acid (PFHxS) 34% (29%–39%). In five locations, comparisons of PFASs in community tap water collected in the period 2013–2016 with samples from 1989–1990 indicated increases in quantifiable PFAS and extractable organic fluorine (a proxy for unquantified PFAS). Conclusions: Our results for 1989–1990 compare well with the default RSC of 20% used in risk assessments for legacy PFAS by many agencies. Future evaluation of drinking water exposures should incorporate emerging PFAS. https://doi.org/10.1289/EHP4093
Bioconcentration of Per- and Polyfluoroalkyl Substances and Precursors in Fathead Minnow Tissues Environmentally Exposed to Aqueous Film-Forming Foam–Contaminated Waters
Abstract Exposure to per- and polyfluoroalkyl substances (PFAS) has been associated with toxicity in wildlife and negative health effects in humans. Decades of fire training activity at Joint Base Cape Cod (MA, USA) incorporated the use of aqueous film-forming foam (AFFF), which resulted in long-term PFAS contamination of sediments, groundwater, and hydrologically connected surface waters. To explore the bioconcentration potential of PFAS in complex environmental mixtures, a mobile laboratory was established to evaluate the bioconcentration of PFAS from AFFF-impacted groundwater by flow-through design. Fathead minnows (n = 24) were exposed to PFAS in groundwater over a 21-day period and tissue-specific PFAS burdens in liver, kidney, and gonad were derived at three different time points. The ∑PFAS concentrations in groundwater increased from approximately 10,000 ng/L at day 1 to 36,000 ng/L at day 21. The relative abundance of PFAS in liver, kidney, and gonad shifted temporally from majority perfluoroalkyl sulfonamides (FASAs) to perfluoroalkyl sulfonates (PFSAs). By day 21, mean ∑PFAS concentrations in tissues displayed a predominance in the order of liver > kidney > gonad. Generally, bioconcentration factors (BCFs) for FASAs, perfluoroalkyl carboxylates (PFCAs), and fluorotelomer sulfonates (FTS) increased with degree of fluorinated carbon chain length, but this was not evident for PFSAs. Perfluorooctane sulfonamide (FOSA) displayed the highest mean BCF (8700 L/kg) in day 21 kidney. Suspect screening results revealed the presence of several perfluoroalkyl sulfinate and FASA compounds present in groundwater and in liver for which pseudo-bioconcentration factors are also reported. The bioconcentration observed for precursor compounds and PFSA derivatives detected suggests alternative pathways for terminal PFAS exposure in aquatic wildlife and humans. Environ Toxicol Chem 2024;43:1795–1806. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Flow-through dosing experiments utilizing aqueous film-forming foam (AFFF)–contaminated groundwater revealed positive linear correlations between fluorinated carbon chain length and logarithm-transformed bioconcentration factors (BCFs) for perfluoroalkyl sulfonamides identified in fathead minnow (Pimephales promelas) liver via target analysis and suspect screening using high-resolution mass spectrometry. FBSA = perfluorobutane sulfonamide; FHxSA = perfluorohexane sulfonamide; FOSA = perfluorooctane sulfonamide; FPeSA= perfluoropentane sulfonamide; FPrSA = perfluoropropane sulfonamide.
Guideline levels for PFOA and PFOS in drinking water: the role of scientific uncertainty, risk assessment decisions, and social factors
Communities across the U.S. are discovering drinking water contaminated by perfluoroalkyl and polyfluoroalkyl substances (PFAS) and determining appropriate actions. There are currently no federal PFAS drinking water standards despite widespread drinking water contamination, ubiquitous population-level exposure, and toxicological and epidemiological evidence of adverse health effects. Absent federal PFAS standards, multiple U.S. states have developed their own health-based water guideline levels to guide decisions about contaminated site cleanup and drinking water surveillance and treatment. We examined perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) water guideline levels developed by the U.S. Environmental Protection Agency (EPA) and state agencies to protect people drinking the water, and summarized how and why these levels differ. We referenced documents and tables released in June 2018 by the Interstate Technology and Regulatory Council (ITRC) to identify states that have drinking water and groundwater guideline levels for PFOA and/or PFOS that differ from EPA’s health advisories (HAs). We also gathered assessment documents from state websites and contacted state environmental and health agencies to identify and confirm current guidelines. Seven states have developed their own water guideline levels for PFOA and/or PFOS ranging from 13 to 1000 ng/L, compared to EPA’s HA of 70 ng/L for both compounds individually or combined. We find that the development of PFAS guideline levels via exposure and hazard assessment decisions is influenced by multiple scientific, technical, and social factors, including managing scientific uncertainty, technical decisions and capacity, and social, political, and economic influences from involved stakeholders. Assessments by multiple states and academic scientists suggest that EPA’s HA is not sufficiently protective. The ability of states to develop their own guideline levels and standards provides diverse risk assessment approaches as models for other state and federal regulators, while a sufficiently protective, scientifically sound, and enforceable federal standard would provide more consistent protection.
Understanding Mechanisms of PFAS Absorption, Distribution, and Elimination Using a Physiologically Based Toxicokinetic Model
Abstract. Exposures to some per- and polyfluoroalkyl substances (PFAS), including perfluoroalkyl acids (PFAA), have been associated with diverse adverse he
Delayed discovery, dissemination, and decisions on intervention in environmental health: a case study on immunotoxicity of perfluorinated alkylate substances
Identification and characterization of environmental hazards that impact human health must rely on the best possible science to inform and inspire appropriate public health intervention. The perfluorinated alkylate substances (PFASs) are persistent emerging pollutants that are now being recognized as important human health hazards. Although the PFASs have been produced for over 60 years, academic research on environmental health aspects has appeared only in the most recent 10 years or so. In the meantime, these persistent chemicals accumulated in the global environment. Some early studies e.g., on population exposures and toxicity, were not released to the public until after year 2000. Still, the first PFAS risk assessments ignored these reports and relied on scant journal publications. The first guidelines and legal limits for PFAS exposure, e.g., from drinking water, were proposed 10 years ago. They have decreased substantially since then, but remain higher than suggested by data on human adverse effects, especially on the immune system, that occur at background exposure levels. By now, the best-known PFASs are being phased out, and related PFASs are being introduced as substitutes. Given the substantial delays in discovery of PFAS toxicity, in dissemination of findings, and in regulatory decisions, PFAS substitutes and other persistent industrial chemicals should be subjected to prior scrutiny before widespread usage.
