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The toxicity and environmental persistence of anthropogenic per- and poly-fluoroalkyl substances (PFAS) are of global concern. To address legacy PFAS concerns in the United States, industry developed numerous replacement PFAS that commonly are treated as confidential information. To investigate the distribution of PFAS in New Jersey, soils collected from across the state were subjected to nontargeted mass-spectral analyses. Ten chloroperfluoropolyether carboxylates were tentatively identified, with at least three congeners in all samples. Nine congeners are ≥(CF₂)₇. Distinct chemical formulas and structures, as well as geographic distribution, suggest airborne transport from an industrial source. Lighter congeners dispersed more widely than heavier congeners, with the most widely dispersed detected in an in-stock New Hampshire sample. Additional data were used to develop a legacy-PFAS fingerprint for historical PFAS sources in New Jersey.

From 1980 to 2017, a fluorochemical manufacturing facility discharged wastewater containing poorly understood per- and polyfluoroalkyl substances (PFAS) to the Cape Fear River, the primary drinking water source for Wilmington, North Carolina, residents. Those PFAS included several fluoroethers including HFPO-DA also known as GenX. Little is known about the bioaccumulation potential of these fluoroethers. We determined levels of fluoroethers and legacy PFAS in serum samples from Wilmington residents. In November 2017 and May 2018, we enrolled 344 Wilmington residents of age into the GenX Exposure Study and collected blood samples. Repeated blood samples were collected from 44 participants 6 months after enrollment. We analyzed serum for 10 fluoroethers and 10 legacy PFAS using liquid chromatography-high-resolution mass spectrometry. Participants' ages ranged from 6 to 86 y, and they lived in the lower Cape Fear Region for 20 y on average (standard deviation: 16 y). Six fluoroethers were detected in serum; Nafion by-product 2, PFO4DA, and PFO5DoA were detected in of participants. PFO3OA and NVHOS were infrequently detected. Hydro-EVE was present in a subset of samples, but we could not quantify it. GenX was not detected above our analytical method reporting limit ( ). In participants with repeated samples, the median decrease in fluoroether levels ranged from 28% for PFO5DoA to 65% for PFO4DA in 6 months due to wastewater discharge control. Four legacy PFAS (PFHxS, PFOA, PFOS, PFNA) were detected in most ( ) participants; these levels were higher than U.S. national levels for the 2015-2016 National Health and Nutrition Examination Survey. The sum concentration of fluoroethers contributed 24% to participants' total serum PFAS (median: ). Poorly understood fluoroethers released into the Cape Fear River by a fluorochemical manufacturing facility were detected in blood samples from Wilmington, North Carolina, residents. Health implications of exposure to these novel PFAS have not been well characterized. https://doi.org/10.1289/EHP6837.

Various countries have instituted risk governance measures to control and minimize the risks of chemicals at the national and international levels. Activities typically include risk assessment based on ) hazard and exposure assessments; ) setting limits on the production, use, and emissions of chemicals; ) enforcement of regulations; and ) monitoring the effectiveness of the measures taken. These steps largely depend on chemical analysis and access to pure chemical reference standards. However, except for specific highly regulated categories of chemicals, such reference standards often are not commercially available. This raises a critical question: Given the widespread lack of reference standards, is the current approach to governing chemicals adequate to protect humans and the environment from harm? If not, what measures could be taken to improve the situation? We outline how current chemical risk governance is hampered by the widespread lack of reference standards to produce the required scientific evidence. We also provide a list of recommendations for controlling chemical risks in the absence of reference standards. We use per- and polyfluoroalkyl substances (PFASs), specifically the chemical C6O4 [perfluoro ([5-methoxy-1,3-dioxolan-4-yl]oxy) acetic acid], to illustrate how companies that produce chemicals can prevent access to reference standards. We argue that the very limited availability of reference standards undermines the ability of scientists to produce independent scientific evidence needed for chemical risk governance and, thereby, prevents society from protecting people and the environment against chemical pollution and its harms. Possible ways to improve the situation include ) guaranteeing access to chemical reference standards by creating a reference standards repository, ) redefining the level of confidence sufficient for regulatory action, ) providing alternative options for chemical identification and quantification when reference standards are not available, and ) considering, when no reference standards are available, regulation of chemicals by class rather than individually. https://doi.org/10.1289/EHP12331.

Due to their unique properties, perfluorinated substances (PFAS) are widely used in multiple industrial and commercial applications, but they are toxic for animals, humans included. This review presents some available data on the PFAS environmental distribution in the world, and in particular in Europe and in the Veneto region of Italy, where it has become a serious problem for human health. The consumption of contaminated food and drinking water is considered one of the major source of exposure for humans. Worldwide epidemiological studies report the negative effects that PFAS have on human health, due to environmental pollution, including infertility, steroid hormone perturbation, thyroid, liver and kidney disorders, and metabolic disfunctions. In vitro and in vivo researches correlated PFAS exposure to oxidative stress effects (in mammals as well as in other vertebrates of human interest), produced by a PFAS-induced increase of reactive oxygen species formation. The cellular antioxidant defense system is activated by PFAS, but it is only partially able to avoid the oxidative damage to biomolecules.

Perfluorinated alkyl substances, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are toxic materials that are known to globally contaminate water, air, and soil resources. Strategies for the simultaneous detection and removal of these compounds are desired to address this emerging health and environmental issue. Herein, we develop a type of guanidinocalix[5]arene that can selectively and strongly bind to PFOS and PFOA, which we use to demonstrate the sensitive and quantitative detection of these compounds in contaminated water through a fluorescent indicator displacement assay. Moreover, by co-assembling iron oxide nanoparticle with the amphiphilic guanidinocalix[5]arene, we are able to use simple magnetic absorption and filtration to efficiently remove PFOS and PFOA from contaminated water. This supramolecular approach that uses both molecular recognition and self-assembly of macrocyclic amphiphiles is promising for the detection and remediation of water pollution. Design of materials which allow for simultaneous detection and removal of water pollutants is challenging. Here the authors develop a guanidinocalix[5]arene that selectively binds perfluorinated alkyl substances and allows for fluorescence detection as well as removal of the pollutants in contaminated water.

Products containing per- and polyfluoroalkyl substances (PFAS) have been used for decades in industrial and consumer products. These compounds are persistent in the environment, bioaccumulative, and some are toxic to humans and other animals. Since the early 2000s, laws, policies, and regulations have been implemented to reduce the prevalence of PFAS in the environment and exposures to PFAS. We conducted a scoping literature review to identify how PFAS are regulated internationally, at the U.S. national level, and at the U.S. state level, as well as drivers of and challenges to implementing PFAS regulations in the U.S. This review captured peer-reviewed scientific literature (e.g., PubMed), grey literature databases (e.g., SciTech Premium Collection), Google searches, and targeted websites (e.g., state health department websites). We identified 454 relevant documents, of which 61 discussed the non-U.S. PFAS policy, 214 discussed the U.S. national-level PFAS policy, and 181 discussed the U.S. state-level PFAS policy. The drivers of and challenges to PFAS regulation were identified through qualitative analysis. The drivers of PFAS policy identified were political support for regulation, social awareness of PFAS, economic resource availability, and compelling scientific evidence. The challenges to implementing PFAS regulations were political limitations, economic challenges, unclear scientific evidence, and practical challenges. The implications for PFAS policy makers and other stakeholders are discussed.

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. This study estimates the RSC of tap water to overall PFAS exposure among members of the general U.S. 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. Tap water perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA) were statistically significant predictors of plasma concentrations among individuals who consumed [Formula: see text] 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). 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.

Researchers are struggling to assess the dangers of nondegradable compounds used in clothes, foams and food wrappings. The fluorine detectives Researchers are struggling to assess the dangers of nondegradable compounds used in clothes, foams and food wrappings. Credit: Stefan Rousseau/AFP/Getty

Per- and polyfluoroalkyl substances (PFAS) involve multiple per- and polyfluorinated compounds that are widely used globally. Legacy PFAS, including PFOA, PFOS, and PFHxS, were manufactured before 2000 in various industrialized nations, then gradually phased out in accordance with the Stockholm Convention. Due to the substantial accumulation of these legacy PFAS compounds, their concentrations in drinking water are regulated in some countries. This review first summarizes the historical background of PFAS, followed by a description of their chemical properties. The clinical manifestations of legacy PFAS in humans, such as dyslipidemia, attenuated immune function, and chronic kidney disorders, are also summarized. Emerging PFAS involve Gen-X and F-53B as well as numerous newly developed chemicals with their associated precursors/metabolites, including volatile PFAS. Research on these emerging PFAS compounds in the environment continues to grow, building a substantial body of evidence about their effects. The chemical structure of emerging PFAS shows a wide variety: they could contain ether, ester, sulfoneamide, and other halogen atoms rather than fluorine. Volatile PFAS involve the fluorotelomer 6:2 FTOH and other short-chain PFAS compounds, which are best measured by GC-MS. This review also briefly summarizes the assay for total oxidizable precursors of PFAS, an LC-MS-based assay for an emerging assay that will be used for a quantitative estimation of total PFAS, including emerging PFAS.