Spatiotemporal distribution of legacy and alternative per- and Polyfluoroalkyl substances (PFASs) in major rivers of the Pearl river delta.

Use of per- and polyfluoroalkyl substance (PFAS)-containing aqueous film-forming foams (AFFF) at firefighting training sites (FFTS) has been linked to PFAS contamination of drinking water. This study investigated PFAS transport and distribution in an urban groundwater aquifer used for drinking water production that has been affected by PFAS-containing AFFF. Soil, sediment, surface water and drinking water were sampled. In soil (n = 12) at a FFTS with high perfluorooctane sulfonate (PFOS) content (87% of ∑PFAS), the ∑PFAS concentration (n = 26) ranged from below detection limit to 560 ng g−1 dry weight. In groundwater (n = 28), the ∑PFAS concentration near a military airbase FFTS reached 1000 ng L−1. Principal component analysis (PCA) identified the military FFTS as the main source of PFAS contamination in drinking water wellfields >10 km down-gradient. Groundwater samples taken close to the military FFTS site showed no ∑PFAS concentration change between 2013 and 2021, while a location further down-gradient showed a transitory 99.6% decrease. Correlation analysis on PFAS composition profile indicated that this decrease was likely caused by dilution from an adjacent conflating aquifer. ∑PFAS concentration reached 15 ng L−1 (PFOS 47% and PFHxS 41% of ∑PFAS) in surface river water (n = 6) and ranged between 1 ng L−1 and 8 ng L−1 (PFHxS 73% and PFBS 17% of ∑PFAS) in drinking water (n = 4). Drinking water had lower PFAS concentrations than the wellfields due to PFAS removal at the water treatment plant. This demonstrates the importance of monitoring PFAS concentrations throughout a groundwater aquifer, to better understand variations in transport from contamination sources and resulting impacts on PFAS concentrations in drinking water extraction areas.

Fate and transport of per- and polyfluoroalkyl substances (PFAS) across the groundwater-to-estuary continuum in an aqueous film forming foam (AFFF)-impacted watershed.

In Spring 2013, the Institute of Water Research of the Italian National Research Centre published a study on the presence of perfluoroalkyl substances (PFAS) in the main Italian river basins, unveiling a serious contamination of water bodies and drinking water across the provinces of Vicenza and Padua.PFAS are man-made chemicals with a completely fluorinated carbon chain of various length, widely used for their heat-resistant and grease- and water-repelling properties. Until recently, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were the two most employed PFAS congeners. PFAS are exploited for the production of fluoropolymers, non-stick and waterproof coverings, fire-fighting foams, lubricants, drugs, cosmetics, and pesticides. PFOA and PFOS are highly persistent in the environment and can spread at long distances through water and air. Moreover, they accumulate in biological tissues and along the food chain.The European Union Regulation 757/2010/EU included PFOS among Persistent Organic Pollutants (POPs). In 2013, PFOA was classified as a Persistent-Bioaccumulative-Toxic (PBT) substance and more recently (Reg. 2017/100/EU) it was added to the Annex XVII of the REACH Regulation (Reg. 1907/2006/EC). When the PFAS contamination in the Veneto Region was discovered, there were no enforceable thresholds for these substances in the various environmental matrices (soil, surface water, groundwater, drinking water). Afterwards, the European Directive 2013/39/EU added PFOS to the list of priority hazardous substances for water policy and set up Quality Standars in surface water and biota. Italy implemented the above-mentioned Directive with the Legislative Decree no. 172 of October 13th 2015, which also established Quality Standars in surface water for five more perfluorinated compounds (PFOA; perfluorobutanoic acid, PFBA; perfluorobutane sulfonate, PFBS; perfluoropentanoic acid, PFPeA; and perfluorohexanoic acid, PFHxA). Moreover, with Decree of July 6th 2016 the Italian Ministry of Environment established legal thresholds for PFBS, PFPeA, PFHxA, PFOA, and PFOS in groundwater. As regards drinking water, in January 2014 the Italian Ministry of Health issued a statement of the National Institute of Health setting up performance thresholds for PFOA, PFOS and the sum of other PFAS. Recently, with Deliberation no. 1590 of October 3rd 2017, the Veneto Regional Government established new and stricter performance thresholds in drinking water taking advantage of improved water filtering technologies, with the aim of attaining the maximum available protection of population health according to the precautionary principle.To tackle the issue of PFAS pollution, the Veneto Region adopted an integrated methodology for risk analysis and management, which took into account any possible exposure pathway for the population and required the coordinated action of many different Institutions and Stakeholders, under the oversight of the Regional Directorate of Prevention, Food Safety, and Veterinary Health.Municipalities involved in the contamination were identified and environmental matrices were analysed with the aim of performing a Health Impact Assessment and defining a Health Surveillance Plan for the exposed population.

The treatment of per‐ and polyfluoroalkyl substances (PFAS) within groundwater is an emerging topic, with various technologies being researched and tested. Currently, PFAS‐impacted groundwater is typically treated ex situ using sorptive media such as activated carbon and ion exchange resin. Proven in situ remedial approaches for groundwater have been limited to colloidal activated carbon (CAC) injected into aquifers downgradient of the source zones. However, treatment of groundwater within the source zones has not been shown to be feasible to date. This study evaluated the use of CAC to treat dissolved PFAS at the air–water interface within the PFAS source zone. Studies have shown that PFAS tends to preferentially accumulate at the air–water interface due to the chemical properties of the various PFAS. This accumulation can act as a long‐term source for PFAS, thus making downgradient treatment of groundwater a long‐term requirement. A solution of CAC was injected at the air–water interface within the source zone at a site with PFAS contamination using direct push technology. A dense injection grid that targeted the interface between the air and groundwater was used to deliver the CAC. Concentrations of PFAS within the porewater and groundwater were collected using a series of nine lysimeters installed within the vadose and saturated water columns. A total of six PFAS were detected in the porewater and groundwater including perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA). Detectable concentrations of PFAS within the pore and groundwater before treatment ranged from values greater than 300 µg/L for PFPeA to less than 3 µg/L for PFNA. Following the injection of the CAC, monitoring of the porewater and groundwater for PFAS was conducted approximately 3, 6, 9, 12, and 18 months postinjection. The results indicated that the PFAS within the porewater and groundwater at and near the air–water interface was effectively attenuated over the 1.5‐year monitoring program, with PFAS concentrations being below the method detection limits of approximately 10 ng/L, with the exception of PFPeA, which was detected within the porewater during the 18‐month sampling event at concentrations of up to 55 ng/L. PFPeA is a five carbon‐chained PFAS that has been shown to have a lower affinity for sorption onto activated carbon compared to the longer carbon‐chained PFAS such as PFOA. Examination of aquifer cores in the zone of injection indicated that the total organic carbon concentration of the aquifer increased by five orders of magnitude postinjection, with 97% of the samples collected within the target injection area containing activated carbon, indicating that the CAC was successfully delivered into the source zone.

In recent years, due to the production and use of per- and poly-fluoroalkyl substances (PFASs), the research on the pollution characteristics and sources of PFASs in surface water and precipitation in China has attracted increasing attention. In this study, the related published articles with sampling years from 2010 to 2020 were reviewed, and the concentration levels, composition characteristics and possible sources of PFASs in surface water (rivers and lakes) and precipitation in China were summarized, including those in the Tibetan Plateau region. The results show that the concentrations of PFASs in surface water in different areas of China vary greatly, ranging from 0.775 to 1.06 × 106 ng/L. The production processes of fluorinated manufacturing facilities (FMFs) and sewage discharge from wastewater treatment plants (WWTPS) were the main sources of PFASs in surface water in China, and the concentrations of PFASs in water flowing through cities with high urbanization increased significantly compared with those before water flowed through cities with high urbanization. The compositions of PFASs in surface water gradually changed from long-chain PFASs, such as per-fluoro-octanoic acid (PFOA) and per-fluoro-octanesulfonic acid (PFOS) to short-chain PFASs, such as per-fluorobutanoic acid (PFBA), per-fluorobutanesulfonic acid (PFBS), perfluorohexanoic acid (PFHxA) and per-fluoropentanoic acid (PFPeA). The concentrations of PFASs in precipitation in China ranged from 4.2 to 191 ng/L, which were lower than those of surface water. The precipitation concentrations were relatively high around a fluorination factory and in areas with high urbanization levels. PFASs were detected in the surface water and precipitation in the Tibetan Plateau (TP), which is the global “roof of the world”, but the concentrations were low (0.115–6.34 ng/L and 0.115–1.24 ng/L, respectively). Local human activities and surface runoff were the main sources of PFASs in the surface water of the Tibetan Plateau. In addition, under the influence of the Southeast Asian monsoon in summers, marine aerosols from the Indian Ocean and air pollutants from human activities in Southeast Asia and South Asia will also enter the water bodies through dry and wet depositions. With the melting of glaciers caused by global warming, the concentration of PFASs in the surface water of the TP was higher than that before the melting of glaciers flowed into the surface water of the TP. Generally, this study summarized the existing research progress of PFAS studies on surface water and precipitation in China and identified the research gaps, which deepened the researchers’ understanding of this field and provided scientific support for related research in the future. The concentrations of PFASs in the water bodies after flowing through FMFs were significantly higher than those before water flowed through FMFs, so the discharge of the FMF production process was one of the main sources of PFASs in surface water.

Impacts of rapidly urbanizing watershed comprehensive management on per- and polyfluoroalkyl substances pollution: Based on PFAS “diversity” assessment

Longitudinal trends in per- and polyfluoroalkyl substances (PFAS) serum concentrations across pregnancy have not been thoroughly examined, despite evidence linking prenatal PFAS exposures with adverse birth outcomes. We sought to characterize longitudinal PFAS concentrations across pregnancy and to examine the maternal-fetal transfer ratio among participants in a study of risk and protective factors for adverse birth outcomes among African Americans. In the Atlanta African American Maternal-Child cohort (2014-2020), we quantified serum concentrations of four PFAS in 376 participants and an additional eight PFAS in a subset of 301 participants during early (8-14 weeks gestation) and late pregnancy (24-30 weeks gestation). Among these, PFAS concentrations were also measured among 199 newborns with available dried blood spot (DBS) samples. We characterized the patterns, variability, and associations in PFAS concentrations at different time points across pregnancy using intraclass correlation coefficients (ICCs), maternal-newborn pairs transfer ratios, linear mixed effect models, and multivariable linear regression, adjusting for socioeconomic and prenatal predictors. Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were detected in of maternal samples, with PFHxS and PFOS having the highest median concentrations. We observed high variability in PFAS concentrations across pregnancy time points (). All median PFAS concentrations increased from early to late pregnancy, except for PFOA and N-methyl perfluorooctane sulfonamido acetic acid (NMFOSAA), which decreased [paired -test for all PFAS except for PFOA and perfluorobutane sulfonic acid (PFBS)]. Prenatal serum PFAS were weakly to moderately correlated with newborn DBS PFAS ( ). The median maternal-fetal PFAS transfer ratio was lower for PFAS with longer carbon chains. After adjusting for socioeconomic and prenatal predictors, in linear mixed effect models, the adjusted mean PFAS concentrations significantly increased during pregnancy, except for PFOA. In multivariable linear regression, PFAS concentrations in early pregnancy significantly predicted the PFAS concentrations in late pregnancy and in newborns. We found that the concentrations of most PFAS increased during pregnancy, and the magnitude of variability differed by individual PFAS. Future studies are needed to understand the influence of within-person PFAS variability during and after pregnancy on birth outcomes. https://doi.org/10.1289/EHP14334.

Per- and polyfluoroalkyl substances (PFAS) are a large family of synthetic fluorinated chemicals. Studies using multiple analytical approaches to evaluate PFAS-contaminated soils are still limited, potentially leading to an underestimation of PFAS pollution. This study introduced a stepwise analytical workflow for a comprehensive assessment of organofluorine, integrating total fluorine (TF) determination, extractable organofluorine (EOF) analysis, PFAS target analysis, and PFAS precursor oxidative conversion assay. The workflow was applied to ten field soil samples collected from aqueous film-forming foam (AFFF)-contaminated sites. The sum target PFAS concentration (∑PFAS) ranged from 51.8 to 23200ng/g dry weight. Perfluorooctanesulfonic acid was the predominant PFAS, accounting for 13%-82% (mean value: 53%) of the ∑PFAS. Target PFAS accounted for 1%-80% of the EOF in the soil samples, and the integration of oxidative conversion revealed additional EOF contributions ranging from 0% to 31%. However, a considerable proportion (20%-94%) of unknown organofluorine still persists after combining targeted PFAS analysis and oxidative conversion, likely due to non-oxidizable PFAS, incomplete conversion of unknown PFAS precursors, and persistence of ultra-short chain PFAS post oxidative conversion. In addition, a significant positive correlation was observed between oxidative conversion and EOF results, but not with PFAS target analysis, suggesting that oxidative conversion may better represent the organofluorine burden in AFFF-impacted soils. Our findings indicate that TF analysis is unsuitable for tracing PFAS contamination in soils. Instead, combining oxidative conversion with routine PFAS target analysis is recommended to comprehensively assess PFAS contamination in soils.

Questions remain about the distribution of per- and polyfluoroalkyl substances (PFAS) in the environment, the sources and movement within and between ecosystems, and whether there are effects from such exposure. Information from the Upper Midwest and the mid-Atlantic regions of the United States, which have different PFAS sources, were investigated. Concentrations of Total40 (sum of 40 PFAS), perfluorooctane sulfonate, perfluorohexane sulfonate, and Total13 (sum of 13 PFAS) were consistently higher, by as much as a factor of 40, in tree swallow (Tachycineta bicolor) tissue samples (eggs, nestlings, and diet) at sites along the East Coast, where aqueous film-forming foams (AFFF) were extensively used when compared with East Coast reference sites. Sites in the Upper Midwest, with other PFAS sources, had qualitatively lower concentrations of PFAS than AFFF source sites. Perfluorooctane sulfonate was the only PFAS detected in all samples. Concentrations of most other PFAS, such as the carboxylates and fluorotelomers, did not differ between AFFF and reference sites. Perfluorohexane sulfonate, the second-most common constituent of some legacy AFFF formulations, was <1% of Total40 at the reference sites in eggs and nestlings, but perfluorohexane sulfonate represented up to 9.7% (eggs) and 9.0% (nestlings) at AFFF-influenced sites. Despite differences in PFAS exposure, the daily probability of egg and nestling survival, as well as haptoglobin-like activity (PIT54) and total immunoglobulin Y, was similar across all sites. There were also no significant associations between these end points and concentrations of Total40 or individual PFAS in eggs or nestlings.

Per- and polyfluoroalkyl substances (PFAS) are environmentally persistent contaminants with the potential to adversely affect ecosystem health. Characterizing the spatial dynamics, bioavailability, and potential for biomagnification within exposed ecosystems is necessary for gauging potential risk to wildlife and humans. In this study, we analyzed PFAS concentrations in surface waters, sediments, and biota collected from 30 locations across watersheds on the U.S. Department of Energy's Savannah River Site (SRS). The 800 km2 SRS was designated the Nation's first National Environmental Research Park in 1972, and we contextualize measured PFAS concentrations within a rich history of environmental and ecotoxicological research. Concentrations of total PFAS ranged from non-detect to 2,226 ng/L in water, 65 ng/g in sediment, and 158 ng/g in mosquitofish. Per- and polyfluoroalkyl substances concentrations in fish were elevated despite relatively low concentrations in water and sediment at some locations, demonstrating the importance of including biota for bioavailability assessments. Co-occurrence analyses of PFAS with 22 metals/metalloids revealed strong positive correlations between PFAS and metal concentrations in sediment. At the landscape scale, we identify linkages between PFAS concentrations and watershed landcover dynamics, including watershed size, proportion of watershed development, and sediment composition. Additionally, we examine PFAS concentrations and stable isotope signatures in an impacted stream community and find that sum PFAS, long-chain perfluoroalkyl carboxylic acids (C8 up to C14), perfluorooctane sulfonic acid, and 7:3 fluorotelomer carboxylic acid concentrations were positively related to nitrogen isotope signatures, indicating their potential biomagnification. Collectively, our study characterizes initial environmental and biological PFAS levels on the SRS within stream ecosystems and will serve as a guide for future ecotoxicological studies and risk assessments.

Tackling per- and polyfluorinated alkyl substances in the North African Environment: Slight progress amidst significant challenges

Accumulation and trophic transfer of per- and polyfluoroalkyl substances (PFAS) in estuarine organisms determined via stable isotopes.

As an emerging pollutant, polyfluoroalkyl substances (PFASs) are of significant concern globally, yet the contamination characteristics and sources of PFASs in the cultivation base for the production of raw materials, specifically Hongyingzi sorghum, represented by Moutai Wine, remain largely unknown. In this study, PFASs was tested for the first time in tilled soil (0–20 cm) across eight sample sites in the Hongyingzi sorghum cultivation base using liquid chromatography-triple quadrupole mass spectrometry (LC-TQMS). Two legacy PFASs and five emerging PFASs were detected, with Σ 7 PFAS concentrations ranging from 87.8 to 446 ng/kg and an average concentration of 248 ± 106 ng/kg. The ΣPFAS concentrations, predicted using the ordinary kriging method, were relatively uniform across most of the study area, ranging from 232 to 234 ng/kg. The emerging PFASs contributed 41.8% to the Σ 7 PFASs, and short-chain fluorine-containing products were identified as the primary substitutes for perfluorooctanoic acid (PFOA) in the study area. The principal component analysis results suggested that PFAS pollution originated from PFOA, perfluorononanoic acid, perfluorobutanoic acid, perfluoropentanoic acid, and perfluoroheptanoic acid, which are linked to rural living and agricultural activities, as well as perfluorobutanesulfonic acid, which is associated with industrial activities. The ecological risk assessment indicated that PFOA in the soils in the study area poses a very low ecological risk. In addition, the health risk assessment revealed that the PFASs in the soil do not present a significant risk to human health. These findings provide a scientific basis for the prevention, control, and management of PFAS pollution in the Hongyingzi sorghum cultivation base.

PFASs pollution in Galveston Bay surface waters and biota (shellfish and fish) following AFFFs use during the ITC fire at Deer Park (March 17th–20th 2019), Houston, TX

Associations of legacy and emerging per- and polyfluoroalkyl substances (PFAS) with aquatic communities in a typical subtropical estuary.