Presence of per- and polyfluoroalkyl substances (PFASs) in the Nandu River Estuary, Hainan Island.

Presence and sources of per- and polyfluoroalkyl substances (PFASs) in the three major rivers on Hainan Island.

Estimation of Serum PFOA Concentrations from Drinking and Non-Drinking Water Exposures.

Despite increasing regulatory efforts to reduce production of per- and polyfluoroalkyl substances (PFAS), continued human and ecological exposure to PFAS has led to concerns about historical releases. Municipal wastewater treatment plants (WWTPs) provide important conduits between waste sources and the environment. We present a meta-analysis of results reported in 44 peer-reviewed publications that include 460 influent and 528 effluent samples, collected from 21 countries, for which some or all of five perfluorinated carboxylic acids (PFCAs) and three perfluorinated sulfonic acids (PFSAs) were measured. Our meta analysis revealed global patterns and trends that, to our knowledge, have not been reported elsewhere. Regression analyses of samples collected from 2004 to 2020 quantified the temporal trends of global wastewater effluent concentrations of each of the PFAS and the corresponding mean concentration for each country. Although legacy compounds, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), have been reported with the highest measured concentrations, their global temporal trends are lowest of all PFAS considered. Concentrations of most PFAS analyzed in wastewater in the United States have not changed significantly with time, whereas reported PFAS concentrations in wastewater effluent from China have increased from 11% to 37% per year. In addition, our results show significant positive correlations between previous wastewater effluent concentrations of individual PFAS and the gross domestic product per capita of each country. Our analysis of this global data set also confirmed conclusions from previous studies on smaller data sets: (i) none of the PFAS studied are effectively removed by conventional treatment processes; (ii) effluents from treatment plants that include a significant industrial component to their influent tend to have higher PFAS concentrations; and (iii) the few studies that measured both aqueous concentrations and concentrations adsorbed to suspended particulate matter (SPM) indicate that PFAS adsorbed to SPM can contribute significantly to the total PFAS load.

Invited Perspective: Challenges in Evaluating the Effect of Per- and Polyfluoroalkyl Substance Mixtures on Polycystic Ovarian Syndrome

Carp (Cyprinus carpio) were exposed to perfluoroalkyl acids (PFAAs) including perfluorooctane sulfonate (PFOS) isomers in an artificially contaminated sediment/water microcosm. The uptake constant of PFAAs increased with increasing carbon chain length, whereas the elimination coefficient displayed the opposite trend, suggesting that carbon chain length plays an important role in the bioaccumulation of PFAAs. When the contribution of suspended particulate matter was taken into account, the bioaccumulation factors (BAFs) became lower (3.61-600 L/kg) compared with BAFs derived from only considering the absorption from free PFAAs in water (3.85-97000 L/kg). The results indicate that suspended particulate matter in water constitutes an important source of exposure for aquatic organisms to long-chain PFAAs. Linear (n-)PFOS was preferentially accumulated compared with branched isomers in carp. Among the branched isomers, 1m-PFOS displayed the greatest bioaccumulation, whereas m2 -PFOS had the lowest. Linear PFOS displayed greater partitioning ability from blood to other tissues over branched PFOS (br-PFOS) isomers, leading to a relatively lower n-PFOS proportion in blood. In summary, suspended particulate matter made a contribution to the accumulation of long-chain PFAAs in aquatic organisms, and n-PFOS was preferentially accumulated compared with br-PFOS isomers. Environ Toxicol Chem 2016;35:3005-3013. © 2016 SETAC.

Perfluoroalkyl acids in the aquatic environment of a fluorine industry-impacted region: Spatiotemporal distribution, partition behavior, source, and risk assessment

Enhanced per- and polyfluoroalkyl substances (PFAS) exposure in a large estuary-coastal sea continuum shortly after a spring flood event.

Vol. 129, No. 12 Science SelectionOpen AccessA Measure of Strength: Developmental PFAS Exposures and Bone Mineral Content in Adolescenceis accompanied byAssociations of Maternal Serum Perfluoroalkyl Substances Concentrations with Early Adolescent Bone Mineral Content and Density: The Health Outcomes and Measures of the Environment (HOME) Study Charles W. Schmidt Charles W. Schmidt Search for more papers by this author Published:17 December 2021CID: 124002https://doi.org/10.1289/EHP10551AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail AbstractThe amount of bone mass that accumulates during early childhood and adolescence is a significant factor governing skeletal strength and the risk of osteoporosis in older adults.1,2 Growing evidence suggests developing bone may be damaged by exposures to per- and polyfluoroalkyl substances (PFAS).3 A new study in Environmental Health Perspectives4 associates higher concentrations of PFAS in maternal blood during pregnancy with lower measures of bone strength in adolescent children. The study was led by Jessie Buckley, an associate professor of environmental health and engineering at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland.Resistance to bone diseases such as osteoporosis depends on maximizing bone mass during critical growth periods, which include adolescence. A new study reports associations between higher prenatal PFAS exposures and lower measures of bone strength in 12-year-olds, with potential implications for adult bone health. Image: © Sergey Novikov/Shutterstock.Commonly described as “forever chemicals” because they are exceedingly resistant to degradation, PFAS have been used as stain, oil, and water repellents and as surfactants in fire-fighting foam.5 Certain PFAS are being phased out of production, but other novel formulations are being introduced to take their place.6Buckley and colleagues analyzed data collected by the Health Outcomes and Measures of the Environment (HOME) study, which enrolled pregnant women from Cincinnati, Ohio, and the surrounding areas between 2003 and 2006. This ongoing study aims to assess how fetal and early-life chemical exposures affect children’s growth and development.7 The women provided blood samples at 16 and 26 weeks of pregnancy and within a day of their child’s delivery. For the current study, the investigators measured PFAS in one sample per participant, with all three sampling points represented in the study.Buckley’s team analyzed data for 206 children from the HOME cohort who had also undergone dual-energy X-ray absorptiometry bone scans at 12 years of age. These scans measure inorganic bone mineral, which gives the skeleton its strength.8 Using those data, the researchers calculated two bone measurements: bone mineral content (BMC) and bone mineral density (BMD). The team then looked at how BMC and BMD measures varied with maternal blood concentrations of four PFAS: perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid.Higher concentrations of PFOA and PFNA individually and of all four PFAS assessed as a mixture were associated with lower z-scores for BMC and BMD in the forearm and hip. The lower z-scores suggest that children with higher PFAS exposures had lower average bone mass compared with individuals of the same age, sex, and ancestry. “The mixture’s relationship with bone outcomes was stronger than the relationship [of any single] PFAS,” Buckley says. “This is important, since in the real world people tend to be exposed to mixtures of different PFAS all at once.”Abby Fleisch, a pediatric endocrinologist at Maine Medical Center in Portland, who was not involved in the research, says the study has several strengths. “It identifies gestation as a possible vulnerable window for PFAS exposures to impact bone health later in life,” she says. Furthermore, prospective data gathered so far have been limited to females, whereas Buckley and colleagues studied both sexes. Indeed, higher maternal PFOA concentrations were generally associated with lower z-scores in males compared with females. However, a key limitation, Buckley says, is that small sample sizes resulting from losses during follow-up made it difficult to assess sex-related differences.Still, the study addresses “important questions regarding prenatal exposure to both individual and mixtures of PFAS,” says Meghan Lynch, an environmental epidemiologist and PFAS expert at Abt Associates, an environmental consulting company headquartered in Rockville, Maryland. “Decreases in BMD in childhood are linked to an increase in fractures and the development of osteoporosis,” she says. “More research is needed to understand if this [association with PFAS] persists and if it is exacerbated by ongoing exposure to PFAS through adolescence and beyond.”Charles W. Schmidt, MS, is an award-winning journalist in Portland, ME, whose work has appeared in Scientific American, Nature, Science, Discover Magazine, Undark, the Washington Post, and many other publications.

Introduction Poly- and perfluoro alkyl substances (PFASs), also known as “forever chemicals”, are persistent in the environment and are challenging to eliminate. There is a growing concern over their widespread presence in the environment and potential adverse effects on human health and ecosystems. Most of the current studies on PFAS pollution are related to aqueous and soil matrices while less emphasis has been given to their relevance to air quality. Several recent studies reported presence of PFASs in atmosphere; however, their atmospheric sources, especially for restricted for more than a decade perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), are not well understood (e.g. Kourtchev et al., 2022; Zhou et al., 2021). Wastewater treatment (WWT) plants are repositories of 1000s of pollutants including PFASs (Barisci & Suri, 2021). Aerosolisation/volatilisation during WWT processes (e.g., aeration, trickling filtration) is suggested as one of the potential sources of PFASs in the atmosphere. However, to the best of our knowledge, aerosolisation potential of PFASs was conducted on a very small number of molecules from that class and under relevant to other than WWT processes conditions e.g., seaspray. The aim of this work is to investigate, for the first time, the aerosolisation potential of the extensive number of PFASs from contaminated waters under relevant to WWT plant conditions.Method and resultsAerosolisation potential of PFASs, covering short-, medium- and long-chain compounds and including legacy PFOA, PFOS and perfluorononanoic acid (PFNA), was examined by aerating PFAS-fortified aqueous solutions at relevant to wastewater effluent concentrations and pHs in an aeration chamber. The generated PFAS-enriched aerosol was collected onto a prebaked glass fiber filter and methanolic solution using a filter pack, and an impinger. The samples were extracted and analysed using an on-line solid phase extraction (SPE) liquid chromatography (LC)-Orbitrap-Mass spectrometry (MS). The PFAS decay from the fortified aqueous solutions were also monitored to understand the extent of PFAS partitioning onto aerosol.Our study indicates that a significant fraction of PFASs can be aerosolised from the contaminated water. This effect was more pronounced for long-chain PFASs irrespective of the pH of the contaminated water. Perfluorocarboxylic acids showed an increase in aerosol phase enrichment with increasing carbon chain length. Short chain PFASs showed lowest aerosol phase enrichment and losses from the contaminated water.ConclusionsThis study, for the first time, establishes the liquid-to-air transfer potential of 15 persistent semi-volatile PFASs including new generation replacements for legacy PFASs such as 4:2 fluorotelomer sulfonate (4:2 FTS) and 8:2 fluorotelomer sulfonate (8:2 FTS) via aerosolisation. The aerosolisation tendency of PFASs was found to increase with increasing carbon chain length. Legacy PFOS and PFOA were detected in the aerosol phase at alarming concentrations suggesting that the contaminated with PFAS waters exposed to aeration can be responsible for  observation of “forever chemicals” in the atmosphere. Reference: Barisci and Suri, Water Sci.Technol., 84(12), 3442-3468. https://doi.org/10.2166/wst.2021.484Kourtchev et al.  Sci. Total Environ., 835, 155496. https://doi.org/10.1016/j.scitotenv.2022.155496Zhou et al. Environ.Sci.: Processes Impacts, 23(4), 580-587. https://doi.org/10.1039/D0EM00497A

Time-dependent effects of perfluorinated compounds on viability in cerebellar granule neurons: Dependence on carbon chain length and functional group attached

Perfluoroalkyl substances (PFASs) in wastewater treatment plants and drinking water treatment plants: Removal efficiency and exposure risk

Per- and polyfluoroalkyl substances (PFAS) are extensively used in urban environments and are, thus, found in urban stormwater. However, the relevance of stormwater as a pathway for PFAS to urban streams is largely unknown. This study evaluated the impact of urban stormwater runoff on PFAS concentrations and spatial distribution in three urban streams affected by stormwater discharges from separate sewer systems. River water was sampled during dry (DW) and wet weather (WW) upstream, immediately downstream, and further downstream of three urbanized areas with separate sewer systems and with and without point sources (i.e. waste water treatment plant, airports). Water samples were analyzed for 34 targeted PFAS compounds and sediment samples for 35 targeted PFAS and 30 PFAS compounds using a total oxidizable precursor assay. The sum of the quantified PFAS concentrations ranged from the reporting limit (RL) to 84.7 ng/L during DW and increased as the streams were affected by WW discharges (0.87 to 102.3 ng/L). The highest PFAS concentrations were found downstream of urban areas and/or point sources (i.e. airports) during WW, indicating a clear contribution from stormwater discharges. A consistent PFAS contribution from the WWTP was observed under both DW and WW conditions. During WW events, concentrations of perfluorooctanesulfonic acid (PFOS) and total PFAS (PFOA equivalents) exceeded the annual average environmental quality standards, which are an established limit of 0.65 ng/L for PFOS and a proposed limit of 4.4 ng/L for total PFAS. Notably, except for the legacy PFAS, PFOS and perfluorooctanoic acid (PFOA), the most frequently quantified PFAS during DW were short-chain. For WW, long-chain perfluorocarboxylic acids (PFCAs) and a precursor, 6:2 Fluorotelomer sulfonic acid (6:2 FTS), were more frequently quantified, suggesting stormwater is a source of these longer-chain and particle-associated PFAS. The detection of unregulated fluorotelomer sulfonates (FTSs) such as 6:2 and 8:2 FTS during WW suggests a need for regulatory action, as these compounds can degrade into more stable PFAS. In sediment, higher concentrations, and a greater variety of PFAS were found at sites with known point sources i.e. airports. Long-chain PFCAs (C7-C13), perfluoroalkyl sulfonates (PFSAs) (C6), and precursors (i.e. N-Ethyl perfluorooctane sulfonamidoacetic acid), were more prevalent in sediments than in the water. Notably, PFOS concentrations in sediment exceeded the lowest Predicted No-Effect Concentration (PNEC) across sites, posing a potential long-term environmental risk, though current PNECs for other PFAS may underestimate such risks. The findings of the study highlight urban stormwater as a source of PFAS to urban streams indicating the need to minimize PFAS sources in the urban environment and to effectively treat stormwater to protect receiving water bodies.

Perfluoroalkyl acids (PFAAs) in the aquatic food web of a temperate urban lake in East China: Bioaccumulation, biomagnification, and probabilistic human health risk

Per- and polyfluoroalkyl substances (PFAS) are a class of persistent environmental contaminants associated with adverse human health effects. Wastewater treatment plants and stormwater are known sources of PFAS in aquatic environments, but the composition and fate of PFAS in urban sewer systems remains poorly understood, particularly for perfluoroalkyl acid (PFAA) precursors. To address this uncertainty, we studied PFAS occurrence, composition, and PFAA precursor contributions in wastewater treatment plants and stormwater discharges across six Iowa cities. Using targeted analysis, 9 PFAS were quantified in wastewater and 13 PFAS were quantified in stormwater. The TOP assay was used to estimate unidentified precursors. Wastewater influent contained 41.9 - 342.3 ng/L total PFAS, and effluent contained 16.5 - 330.1 ng/L total PFAS. Precursors constituted 50 - 100% of influent PFAS and 4 – 58% of effluent PFAS. Total stormwater PFAS concentrations reached 85.3 ng/L, with up to 79% of the mass as PFAA precursors. Perfluorohexanoic acid (PFHxA) and perfluorooctanoic acid (PFOA) were the most common terminal PFAAs, suggesting that precursors with six and eight perfluorinated carbons (e.g., 6:2 and 8:2 fluorotelomers) are common in wastewater and stormwater. PFAS composition and removal removal varied across wastewater treatment plants and sampling events, as influenced by sources and hydrological conditions. Higher wastewater flows were often associated with more abundant precursor PFAS in wastewater effluent. This study emphasizes the substantial presence of unidentified precursor PFAS in urban water discharges. Recognizing the ubiquity of precursors highlights the importance of quantifying total PFAS beyond just targeted monitoring. Overall, this research underscores the necessity for an improved understanding of PFAA precursor fate and transport to guide regulations and protective strategies for human and environmental health.

Exposure to per and poly-fluoroalkyl substances (PFAS) is suggested to interfere with the central nervous system that may affect mental health. Studies on the relationships between exposure to PFAS mixtures and anxiety in humans are rare. This study aimed to evaluate the associations between single and combined exposure to PFAS and anxiety among adults. Data were extracted from the National Health and Nutrition Examination Survey (NHANES, 2007-2012). Six serum PFAS concentrations were accessed including perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), PFOS (perfluorooctanesulfonic acid), PFHxS (perfluorohexane sulfonate), PFDA (perfluorodecanoic acid), Me-PFOSA-AcOH (2-(N-methylperfluorooctanesulfonamide) acetic acid). The anxiety state was defined through the questionnaire responses of the participants. Weighted logistics regression was used to calculate their odds ratio (OR) and corresponding confidence interval (95% CI) that assessed the relationship between PFAS exposure and anxiety. Moreover, Two different statistical methods including quantile-based g-computation (Qgcomp), and Bayesian kernel machine regression (BKMR) were employed to investigate the overall effects of PFAS mixtures on anxiety. The effects of specific PFAS exposure on anxiety varied by sex. In male participants, one-unit increase in PFDA (OR = 0.62; 95%CI: 0.44, 0.88), PFOA (OR = 0.60; 95%CI: 0.41, 0.87), PFNA (OR = 0.68; 95%CI: 0.46, 0.96) concentrations were inversely linked to anxiety. In female participants, a one-unit increase in PFOA (OR = 1.50; 95%CI: 1.05, 2.14) concentration was associated with anxiety. Analysis of Qgcomp demonstrated that PFAS mixtures were negatively associated with anxiety in males (OR = 0.85; 95%CI: 0.74, 0.99), and were positively associated with anxiety in females(OR = 1.16; 95%CI: 1.01, 1.33). Analysis of BKMR suggested that PFAS mixtures were negatively associated with anxiety in the males, while its associations with anxiety were positive in the females. Although a growing number of studies have focused on the relationship between PFAS and anxiety, most have been performed based on animal observations rather than human populations, and the combined effects of PFAS mixtures on anxiety have not been evaluated. To address these gaps, this study first explored the associations between individual PFAS and PFAS mixture exposures and anxiety among US adults. Using data from the National Health and Nutrition Examination Survey, we demonstrated that co-exposure to a mixture of PFAS was negatively associated with anxiety in males, and its association was contrary in females.