Open dumps as a critical source of per- and polyfluoroalkyl substances in agricultural soils of Pakistan: evidence of trifluoroacetic acid dominance.

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.

Polyfluoroalkyl substances in Danjiangkou Reservoir, China: Occurrence, composition, and source appointment

It's not all about PFAS: Metal(loid)s are associated with physiological and metabolic changes in a native frog from conservation wetlands.

Concentrations and Exposure Risks of Per- and Polyfluoroalkyl Substances in Human Milk from Southern China During the First 400 days of Lactation

BackgroundPer- and polyflouralkyl substances (PFAS) are a group of persistent chemicals used extensively in industries and consumer products due to their water-repellent properties. Studies have linked PFAS exposure to adverse health effects, and human exposure to PFAS, especially during pregnancy, is of great concern. In this study, we report how serum PFAS concentrations during pregnancy correlated with serum PFAS of partners from the same household. Further, we report how serum PFAS concentrations change during the course of pregnancy and associations between PFAS and blood lipid concentrations as well as exploratory analyses of associations between physical activity and PFAS concentrations.MethodsIn this secondary analysis of data from the FitMum study conducted from 2018 to 2021, 216 healthy, pregnant women, and 110 of their partners were included. Non-fasting venous blood samples were collected from the mothers at three test visits during pregnancy and at delivery, where blood from partners were also collected. Serum samples from all timepoints were analyzed for 15 short- and long-chained PFAS using liquid chromatography triple quadrupole linear ion trap mass spectrometry. Total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride blood concentrations were measured at three test visits during pregnancy and at delivery. Physical activity was measured with a wrist-worn activity tracker 24/7 from inclusion before gestational age week 15 + 0 and throughout pregnancy.ResultsIn serum samples we detected the following PFAS: PFOS, PFOA, PFHxS, PFNA, PFDA, and PFUnDA. The maternal median concentrations at baseline were: PFOS: 4.09 ng/mL, PFOA: 0.81 ng/mL, PFHxS: 0.29 ng/mL, PFNA: 0.42 ng/mL, PFDA: 0.25 ng/mL, and PFUnDA: 0.19 ng/mL. Partner serum PFAS concentrations were 3–145% higher than maternal concentration (except for PFUnDA). PFAS concentrations correlated within couples. All PFAS decreased significantly during pregnancy (PFOS -23.1 percent 95%-CI [-31.9;-13.2] from baseline to delivery). All PFAS concentrations were associated with increased HDL-C concentrations. No associations between physical activity and maternal PFAS concentrations were found.ConclusionsOverall, serum PFAS concentrations decreased during pregnancy. PFAS concentrations within households were strongly correlated. PFAS and HDL-C concentrations were positively associated. We found no associations between physical activity and serum PFAS concentrations.Trial registrationThe study was registered at ClinicalTrials.gov; NCT03679130; 20/09/2018.

Influence of convective and stratiform precipitation types on per- and polyfluoroalkyl substance concentrations in rain

This study investigated the impact of precursors and bioaccessibility on childhood per- and polyfluoroalkyl substances (PFAS) exposure in house dust (n = 28) from Adelaide, Australia. Sum PFAS concentration (∑38) ranged from 3.0 to 2640 μg kg−1 with PFOS (1.5–675 μg kg−1), PFHxS (1.0–405 μg kg−1) and PFOA (1.0–155 μg kg−1) constituting the major perfluoroalkyl sulfonic (PFSA) and carboxylic acids (PFCA). The total oxidizable precursor (TOP) assay was applied to estimate concentrations of unmeasurable precursors that may undergo oxidation to measurable PFAS. Sum PFAS concentration post-TOP assay changed 3.8–112-fold (91.5–62,300 μg kg−1) with median post-TOP assay PFCA (C4-C8) concentrations (92.3–170 μg kg−1) increasing significantly (13.7–48.5-fold). As incidental dust ingestion is a significant exposure pathway for young children, PFAS bioaccessibility was determined using an in vitro assay. Sum PFAS bioaccessibility ranged from 4.6 to 49.3 % with significantly (p < 0.05) higher PFCA (10.3–83.4 %) bioaccessibility compared to PFSA (3.5–51.5 %). When in vitro extracts were assessed post-TOP assay, PFAS bioaccessibility changed (7–1060 versus 137–3900 μg kg−1) although percentage bioaccessibility decreased (2.3–14.5 %) due to the disproportionately higher post-TOP assay PFAS concentration. PFAS estimated daily intake (EDI) was calculated for a ‘stay-at-home’ 2–3-year-old child. Inclusion of dust specific bioaccessibility values resulted in a 1.7–20.5-fold decrease in ∑PFOA, PFOA and PFHxS EDI (0.02–1.23 ng kg bw−1 day−1) compared to default absorption assumptions (0.23–5.4 ng kg bw−1 day−1). However, when ‘worst-case scenario’ precursor transformation was considered, EDI calculations were 4.1–187-fold higher that the EFSA tolerable weekly intake value (equivalent to 0.63 ng kg bw−1 day−1), although this was moderated when exposure parameters were refined through PFAS bioaccessibility incorporation (0.35–17.0-fold higher than the TDI). Irrespective of exposure scenario, EDI calculations were below the FSANZ tolerable daily intake values for PFOS (20 ng kg bw−1 day−1) and PFOA (160 ng kg bw−1 day−1) for all dust samples analysed.

The occurrence and distributions of per- and polyfluoroalkyl substances (PFAS) in groundwater after a PFAS leakage incident in 2018.

Both emerging and legacy per- and polyfluoroalkyl substances (PFASs) exhibit bioaccumulative and potentially biomagnifying properties, posing risks to ecosystem and human health. This study focused on 26 legacy and emerging PFASs, investigating their concentration profiles, composition, and trophic transfer characteristics in major marine organisms from Laizhou Bay. The results demonstrated that both legacy and emerging PFASs extensively contaminated marine organisms in Laizhou Bay. Variations in PFASs concentration and compositions among different species were strongly associated with species-specific traits, trophic levels, and dietary preferences. The mean log bioconcentration factor (BAF) values of PFASs increased with carbon chain length, with perfluoroalkyl sulfonates (PFSAs) showing higher average log BAF values compared to perfluoroalkyl carboxylates (PFCAs) of the same chain length. In the study area, emerging alternatives such as perfluoro-1-butane-sulfonamide (FBSA) (4.25) and 6:2 fluorotelomer sulfonic acid (6:2 FTSA) (4.52) exhibited log BAF values exceeding 3.7, indicating significant bioaccumulation potential. Moreover, the emerging substitute 6:2 chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA) showed a trophic magnification factor (TMF) of 1.95-exceeding the bioamplification threshold of 1-providing strong evidence of trophic-level transfer and increasing contaminant concentrations in higher trophic organisms. The estimated daily intake (EDI) of perfluorooctanoic acid (PFOA) was relatively high, with a hazard ratio (HR) > 1, highlighting potential health risks for local residents near Laizhou Bay who regularly consume contaminated seafood.

Per- and polyfluoroalkyl substances behavior: Insights from autothermal thermophilic aerobic digestion - Storage nitrification-denitrification reactors

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

Per- and polyfluoroalkyl substances (PFAS) are high-priority pollutants posing significant environmental and health risks. British Columbia, Canada, is a large province in which communities rely on diverse drinking water sources with varying potential for PFAS contamination. However, research on PFAS occurrence in Canadian drinking water, particularly in British Columbia (BC), remains limited. This study presents the first province-wide, comprehensive assessment of PFAS in BC's tap water, analyzing 120 samples collected across the province and targeting 31 PFAS compounds with detection limits of 0.008-2.5ngL-1. While most total PFAS concentrations were below Health Canada's guideline of 30ng L-1, four samples exceeded this threshold. Short-chain PFAS (C6 and shorter) were detected in 74.5% of samples with detectable PFAS, which is consistent with the phase-out of long-chain PFAS, the environmental transformation of precursor compounds, and the greater mobility of short-chain PFAS. Centralized water systems exhibited consistent PFAS concentrations and composition profiles, whereas decentralized systems showed greater variability and appeared more susceptible to PFAS contamination, likely due to diverse contamination sources in the surrounding areas. Since most PFAS levels were low, further efforts should prioritize the small subset of communities with higher concentrations, representing 3.5% of samples collected in this study, and account for the relatively higher prevalence of non-regulated short-chain PFAS.

Bioaccumulation and impact of maternal PFAS offloading on egg biochemistry from wild-caught freshwater turtles (Emydura macquarii macquarii)

Sources and occurrence of per- and polyfluoroalkyl substances in industrial wastewater and assessment of current treatment approaches: A review.

Perfluoroalkyl and polyfluoroalkyl substances removal in a full-scale tropical constructed wetland system treating landfill leachate