Search Results (178)

This study evaluated the reliability and application of relative potency factors (RPFs) for assessing hepatic mixture risks of per- and polyfluoroalkyl substances (PFASs) in Korean finished drinking water. A total of 1254 finished water samples collected from 70 drinking water treatment plants between 2018 and 2024 were analyzed for eight PFAS compounds. Hepatic RPFs proposed by the National Institute for Public Health and the Environment (RIVM) were assessed using a structured scoring system and applied to estimate PFOA-equivalent mixture risks. Hazard quotients (HQs) based on hepatic toxicity reference doses were also calculated for comparison. PFAS concentrations generally declined over time, including PFOA from 0.0032 to 0.0014 μg/L, PFOS from 0.0008 to 0.0003 μg/L, and PFHxS from 0.0072 to 0.0004 μg/L between 2018 and 2024. The RPF-based method produced higher cumulative risk estimates than the individual toxicity-based approach, suggesting that single-compound HQs may underestimate risks from co-occurring PFASs. Although total risks were generally below the non-carcinogenic threshold of 1.0, the 95th percentile PFOA-equivalent risk for PFNA exceeded the individual threshold of 0.1. These findings support endpoint-specific RPF-based assessment for PFAS mixtures in drinking water. Full article

The widespread application of per- and polyfluoroalkyl substances (PFASs) has established perfluorooctanesulfonic acid (PFOS), a representative PFAS, as a critical environmental pollutant. Although PFOS exposure causes significant bioaccumulation and potential myelotoxicity, its specific impact on the chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) remains to be elucidated. In this study, we established a murine model of PFOS exposure to isolate primary BMSCs and investigated this issue through in vitro differentiation assays, cellular senescence evaluations, and an in vivo subcutaneous implantation model using gelatin methacryloyl (GelMA) hydrogel scaffolds. Our results demonstrated that PFOS exposure triggered intracellular reactive oxygen species (ROS) accumulation and induced a senescent phenotype in BMSCs, characterized by restricted cellular proliferation and the release of senescence-associated secretory phenotype (SASP) factors, thereby markedly suppressing their chondrogenic capacity. Mechanistically, the inhibition of the Nrf2 signaling pathway by PFOS was identified as the principal driver of this process. Furthermore, both in vitro and in vivo assays confirmed that pharmacological activation using the Nrf2 agonist sulforaphane (SFN) effectively mitigated the senescent phenotype and restored the chondrogenic potential of PFOS-exposed BMSCs. Altogether, these findings elucidate the specific mechanisms of PFOS-induced stem cell toxicity and offer a potential strategy to overcome the resulting limitations in BMSC-based cartilage regeneration. Full article

Research on the river-groundwater cross-contamination of per- and polyfluoroalkyl substances (PFAS) in karst regions is limited. We therefore investigated the PFAS occurrence, spatial distribution, sources and ecological risks in the Lijiang River basin, a typical karst area. PFAS concentrations were relatively low (0.08–74.0 ng/L, mean 4.13 ng/L). PFBA, PFHxA, PFNA and 6:2 FTS were widely detected. Short-chain PFAS concentrations (0.08–74.0, mean 4.75 ng/L) were higher than long-chain ones (0.02–3.31, mean 0.72 ng/L). Unusually, groundwater PFAS concentrations (0.08–74.0, mean 7.97 ng/L) exceeded those in rivers (0.08–11.7, mean 2.31 ng/L). Positive matrix factorization (PMF) combined with spatial distribution identified five main sources: sewage treatment plants (24.0%), gas station leaks/wastewater discharges (21.3%), untreated domestic sewage (18.1%), small-scale industrial wastewater (16.7%), and agricultural/aquaculture wastewater (20.2%). The ecological risk assessment showed that, except for PFUnDA posing a low risk to algae, the other PFASs presented no significant risk to algae, daphnia or fish. The human health risk assessment indicated minimal direct health risks. Our findings indicate that some PFASs in groundwater and river water may share common sources, highlighting the complex PFAS migration between rivers and groundwater in karst regions. Full article

Per- and polyfluoroalkyl substances (PFASs) are persistent environmental contaminants whose mobility in soil and groundwater is strongly controlled by adsorption and desorption processes. In saturated clay-rich soils, these processes are complex because PFASs interact with hydrated mineral surfaces, organic matter, metal oxides, exchangeable cations, and pore-water constituents. This review synthesizes the current literature on PFAS adsorption and desorption in saturated soils, with an emphasis on clay mineralogy, mineral–water interfaces, pore-water chemistry, and electrochemical double layer (EDL) effects. PFAS retention is influenced by molecular properties such as chain length, functional head group, and charge state, as well as soil properties such as organic carbon content, clay mineral type, surface charge, cation exchange capacity, and Fe/Al oxide content. Longer-chain PFASs and sulfonate-based compounds generally show stronger retention, while shorter-chain PFASs tend to remain more mobile. This review focuses particularly on how an EDL affects PFAS behavior in saturated clay systems. Unlike dry clay surfaces, saturated clay surfaces are covered by structured water, exchangeable ions, and diffuse counterion layers. These hydrated interfacial conditions influence how closely anionic PFASs can approach negatively charged clay surfaces, how dissolved cations reduce electrostatic repulsion or promote cation-mediated binding, and how effectively short-range interactions such as hydrophobic association, van der Waals forces, hydrogen bonding, and surface association contribute to adsorption. Desorption is also emphasized because adsorption does not necessarily represent permanent immobilization. Changes in pH, ionic strength, cation composition, dissolved organic matter, or competing solutes can weaken retention and promote PFAS release. Overall, PFAS mobility in saturated clay-rich soils should be interpreted as a coupled interfacial process rather than simple partitioning to soil solids. Future work should better connect molecular-scale mechanisms, EDL behavior, adsorption–desorption experiments, and saturated transport studies to improve predictions of PFAS retention and long-term groundwater release. Full article

Per- and polyfluoroalkyl substances (PFASs) present a critical challenge to global public health and environmental integrity due to the exceptional stability of the carbon–fluorine (C–F) bond. This review synthesizes current knowledge on PFAS physicochemical properties, exposure pathways, and toxicological outcomes, while evaluating global regulatory efficacy. A central problem addressed in this review is the widening discrepancy between rigid, yet deeply fragmented, international regulatory frameworks and the increasingly complex, non-linear epidemiological data regarding PFAS health risks. While historical paradigms focused heavily on direct carcinogenicity, recent high-resolution data reveal significant heterogeneity and methodological inconsistencies in cancer links. Instead, robust evidence points to severe systemic toxicities—including hepatotoxicity, immunotoxicity, and maternal–fetal disruptions—frequently driven by mixture co-exposures and sex-specific metabolic dimorphisms. Furthermore, the industrial transition to short-chain substitutes has inadvertently compounded the crisis due to their high environmental mobility and resistance to conventional water treatment. By critically evaluating these toxicological and regulatory contradictions, this review demonstrates that current substance-by-substance legislative models fail to mitigate real-world pollution trends. Ultimately, we emphasize the urgent need to transition to holistic mixture modeling, implement unified class-based global regulations, and accelerate advanced destructive remediation technologies to mineralize the resilient C–F bond. Full article

Per- and polyfluoroalkyl substances (PFASs) are persistent emerging contaminants characterized by high environmental stability and biotoxicity. Ubiquitous detection of these contaminants across aquatic environments poses severe threats to ecosystem stability and human health, while constructed wetlands (CWs) serve as a sustainable low-carbon alternative for the remediation of PFAS-laden wastewater. However, traditional mechanisms such as matrix adsorption, phytoaccumulation, and microbial transformation often suffer from low efficiency, rapid saturation, and incomplete degradation. To overcome the above drawbacks, the arbuscular mycorrhizal fungi (AMF)–plant–microbe synergistic consortium has become a promising remediation candidate, which facilitates PFAS immobilization and biodegradation via symbiotic crosstalk among three components. This paper reviews recent advancements in PFAS remediation within AMF-facilitated systems, examining fundamental synergistic mechanisms, treatment efficiencies, and key influencing factors. We propose several optimization strategies, including substrate modification, operational parameter refinement, and the integration of advanced technologies. Furthermore, we emphasize the necessity of elucidating the molecular pathways governing long-chain PFAS degradation and addressing current bottlenecks in engineering applications. Future research should prioritize molecular interaction level interaction mechanisms, the development of anti-interference systems, and field-scale validation. This review provides a theoretical foundation and technical framework for leveraging AMF–plant–microbe synergism to enhance PFAS removal in CWs. Full article

Per- and polyfluoroalkyl substances (PFASs) are persistent environmental contaminants of growing concern for soil ecosystems, yet their effects on the humoral arm of innate immunity in soil invertebrates remain poorly characterized. Here, we used the earthworm Eisenia fetida to screen 31 legacy and emerging PFAS congeners for their ability to modulate the hemolytic activity of cell-free coelomic fluid, a functional readout of soluble immune effectors including the pore-forming toxin lysenin. Earthworms were exposed under OECD 207 contact-filter conditions at two concentrations (0.6 and 229 µM) for 72 h, after which decellularized coelomic fluid was tested against sheep erythrocytes. To dissect direct biochemical interference from organism-mediated regulation, the same panel was also applied ex vivo (2.5 µM) to coelomic fluid from unexposed earthworms. In vivo, PFASs produced markedly heterogeneous, congener-specific responses: PFBS, PFBA and PFMOPrA suppressed hemolytic activity, whereas PMDA, PFHxA and HFPO-DA enhanced it. In contrast, ex vivo exposure produced a consistent, broad inhibition of hemolysis, indicating a direct interaction of PFASs with soluble immune proteins. Proteomic profiling of the lysenin family under PFOA and HFPO-DA suggested isoform-level reweighting rather than uniform abundance shifts, although effects did not survive multiple-testing correction. Together, these data show that PFASs act as congener-specific immunomodulators of extracellular humoral defense in E. fetida and identify candidate congeners for confirmatory mechanistic studies. Full article

To address the environmental evolution and management needs of emerging contaminants in the Yellow River Basin (Henan Section), China, nine typical functional cross-sections, covering industrial outfalls, sewage treatment plant (STP) effluents, human activity-dense areas, and baseline tributaries, were selected to systematically investigate the occurrence, potential sources, and multi-dimensional risks of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in surface water. The results indicated a 100% detection rate of the target pollutants across all sites, with PFOA (0.45–7.46 ng/L) being the absolute dominant analogue. The spatial distribution exhibited an evident industrial point-source-driven pattern, where the pollution loads at the Jili District industrial outfall (S7) and STP effluent (S5) were significantly higher than those in non-point sources and natural baseline waters. Source apportionment suggested that direct wastewater discharge and secondary release from regional industrial clusters were likely key contributors to PFAS spatial heterogeneity. Multi-dimensional risk assessments revealed that the current ecological risk quotients (RQ < 0.01) for aquatic organisms and the human health risk values (HR < 0.1) via drinking water ingestion for various age groups were well within safe and controllable ranges. However, PFOS contributed significantly more to the ecological risk than PFOA, and children exhibited slightly higher health exposure vulnerability than adults. Although the overall risk is minimal, PFOA concentrations at high-load cross-sections have exceeded the latest stringent maximum contaminant level (4.0 ng/L) mandated by the US EPA in 2024. This study suggests an urgent need to establish a dynamic, life-cycle monitoring network for PFASs in the basin and to prioritize targeted deep-reduction strategies for high-risk industrial point sources. Full article

Per- and polyfluoroalkyl substances (PFASs) constitute a chemically diverse family of persistent contaminants, the regulation of which is tightening rapidly in Europe and the United States. Granular activated carbon, selective ion exchange, and pressure-driven membranes remove many long-chain PFASs, but their performance is less robust for short-chain and ultrashort species, and all generate concentrated secondary waste streams. Hydrophobic deep eutectic solvents (DESs), including natural deep eutectic solvents (NADESs), have emerged as tunable liquid extractants able to concentrate PFASs into small solvent volumes that can be regenerated or coupled to destruction. This perspective differs from existing DES-PFAS reviews by converting qualitative solvent-selection arguments into a decision framework with explicit acceptance gates: broad PFAS affinity, a component-resolved non-migration specification for treated water, viscosity and mass-transfer limits, regenerability targets, and techno-economic/life-cycle benchmarking against incumbent processes. We refine the bifunctional DES design hypothesis by separating validated regimes from unresolved cases, identifying the reliability limits of COSMO-RS, molecular dynamics, and machine-learning screening, and defining tiered reporting requirements for early-stage studies. The central message is that PFAS-extracting DES should no longer be evaluated only by single-compound removal percentages; they must be judged as integrated, closed-loop treatment materials with solvent losses, regeneration stability, destruction compatibility, cost, and environmental impacts that are quantified from the outset. Full article

Per- and polyfluoroalkyl substances (PFASs) are persistent aquatic contaminants whose strong C–F bonds make conventional water treatment ineffective. This review critically synthesizes recent progress in aqueous PFAS degradation through four mechanistic routes: oxidation-driven, biodegradation, reduction-driven, and nonradical processes. Rather than evaluating technologies by parent-compound disappearance alone, we compare their defluorination and mineralization capacities, matrix tolerance, byproduct risks, energy demand, operational stability, and technology readiness. Oxidative and reductive systems can promote rapid degradation or defluorination, but their performance is often constrained by radical/electron quenching, incomplete mineralization, and sensitivity to PFAS structure and water chemistry. Biodegradation and enzymatic approaches offer mild transformation pathways but remain limited by slow kinetics, narrow substrate specificity, and uncertain toxicity evolution. Nonradical and thermochemical processes show stronger potential for deep destruction, particularly in concentrated PFAS streams. Overall, electrochemical oxidation, plasma treatment, and thermal/supercritical oxidation appear closer to practical implementation for spent adsorbents, regenerants, industrial concentrates, and other high-strength wastes, whereas many photocatalytic, biological, and microdroplet systems remain laboratory-stage. Future research should prioritize integrated separation–destruction treatment trains and standardized metrics including total organic fluorine removal, fluoride release, final residual PFAS concentrations relative to regulatory thresholds, transformation-product toxicity, energy consumption, and life-cycle impacts. Full article

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are persistent pollutants resistant to conventional treatment processes and pose significant environmental risks. The aim of this study was to comparatively evaluate the metatranscriptomic responses of activated sludge bacterial communities to PFOS and PFOA exposure at environmentally relevant (150 ng/L) and elevated (1050 ng/L) concentrations. Activated sludge from the Zeekoegat Wastewater Treatment Plant (Pretoria, South Africa) was used under aerobic conditions for 45 days. Taxonomic profiling revealed a Proteobacteria-dominated community with distinct pollutant-specific shifts. Under PFOA exposure, Pseudomonas dominated at low concentration, while Achromobacter and Burkholderia increased at higher levels. Under PFOS exposure, Kerstersia dominated at low concentration, whereas Comamonas, Sphingopyxis, and Polaromonas were enriched at higher concentration. Functional analysis revealed increased abundance of stress-response and metabolic pathways, including ABC transporters, chaperonins (GroEL), and β-oxidation. Overall, the results indicate a dose-dependent microbial adaptation, with pollutant type driving functional responses. These findings highlight pollutant-specific microbial responses and adaptation under PFAS exposure in activated sludge systems. These findings highlight pollutant-specific microbial strategies and the potential of activated sludge microbiomes in PFAS transformation processes. Full article

Per- and polyfluoroalkyl substances (PFASs) are persistent micropollutants whose carbon–fluorine bonds resist conventional advanced oxidation. Nonthermal plasmas have emerged as a promising option for PFAS degradation, but the relative contributions of reactive oxygen species (ROS) and electrons are still being investigated. Herein, we compared sinusoidal alternating-current (AC) and nanosecond-pulsed discharges―in an identical plasma reactor with the same input power (30 W)―through diagnostics including voltage–current characterization, optical emission spectroscopy with vibrational and rotational temperatures and Hα Stark broadening for electron density, and aqueous H₂O₂ quantification. AC discharges produced more aqueous H₂O₂, stronger ·OH emission, and higher vibrational and rotational temperatures, yet showed lower perfluorooctanoic acid (PFOA) removal (85% ± 2%) and lower defluorination (61% ± 1%) than the pulsed discharge (96% ± 2% and 80% ± 2%, respectively). Among the diagnostics examined, electron density tracked the removal trend, being higher under pulsed operation (1.2 × 10¹⁶ vs. 8.3 × 10¹⁵ under AC operation). A pseudo-first-order kinetic model based on electron density qualitatively reproduced the observed PFOA decay rate, suggesting that the waveform may serve as a design variable for tuning electron and ROS-mediated pathways in plasma–water reactors. Full article

Per- and polyfluoroalkyl substances (PFASs) in fluorinated firefighting wastewater (FFW), which are difficult to remediate using conventional technologies, represent a critical environmental hazard due to the extreme persistence and bioaccumulation potential of soil–groundwater systems. Niobium-supported boron-doped diamond (BDD) anodes were synthesized by microwave plasma chemical vapor deposition, and their performance in the electrochemical advanced oxidation processes (EAOPs) of FFW were systematically investigated. Under optimized conditions (100 mM Na₂SO₄ electrolyte with 100 mM peroxymonosulfate (PMS), current density of 33.3 mA/cm², pH = 6), the BDD anode achieved near-complete mineralization, with 92.5% total organic carbon (TOC) removal and significant defluorination (77.5% F⁻ release) within 240 min in simulated FFW-contaminated groundwater. For FFW-contaminated soil remediation, 90.2% TOC removal and 41.6% defluorination were achieved after 720 min under optimal treatment (water-to-soil ratio of 20:1). Quenching experiments and electron paramagnetic resonance (EPR) tests revealed that hydroxyl radicals (·OH) and singlet oxygen (¹O₂) were the predominant reactive species. Liquid chromatography–mass spectrometry/mass spectrometry (LC-MS/MS) analysis indicated that PFASs were removed by shortened carbon chains, ultimately mineralizing to CO₂ and F⁻. Toxicity assessment using Vibrio fischeri luminescence demonstrated a reduction in toxicity (from 99.8% to 20.9%), confirming the effective detoxification of BDD-based EAOPs. This work establishes BDD-based EAOPs as a promising technology for eliminating PFASs in groundwater and soil, offering theoretical insights into EAOPs and engineering solutions for PFAS remediation. Full article

Per- and polyfluoroalkyl substances (PFASs) are a large class of thousands of synthetic organofluorine chemical compounds used for many industrial applications. Humans are exposed to PFASs mainly through diet and contaminated drinking water. Studies show that PFASs induce several adverse effects on humans. A great number of human biomonitoring studies have been widely conducted with the aim of estimating exposure to PFASs. The matrices mainly investigated are blood, serum and breast milk. However, in many cases, the need for non-invasive sampling methods with a minimal impact on donors has become paramount to comply with modern ethical standards and regulations. For this reason, we developed a streamlined and efficient method for the analysis of eight perfluorocarboxylic and perfluorosulfonic acids (PFHpA; PFHxS; PFOA; PFHpS; PFNA; PFOS; PFDA; and PFUdA) in human urine samples by UPLC chromatography tandem mass spectrometry. Chromatographic and MS parameters were optimized; the method was validated for: repeatability (<20%), within-lab reproducibility (<20%), trueness (within the set 20% variation limit of agreement between the mean of the data set and the true value), efficiency (51–97%), linearity (R² > 0.99), limits of detection (0.0003 ng/mL), and limits of quantification (0.001 ng/mL). To our knowledge, this is the first published method in Italy for the detection of PFASs in human urine. Full article

Per- and polyfluoroalkyl substances (PFASs) include thousands of fluorinated organic compounds of anthropogenic origin. Their extensive use, combined with their high stability, has led to the widespread contamination of water and soil resources. Here, single-step foam fractionation enhanced soil washing was carried out for the remediation of PFAS-contaminated soil. Concentrations of target Perfluoroalkyl Carboxylic Acids (PFCAs) and Perfluoroalkane Sulfonic Acids (PFSAs) were monitored in foam and leachate along the duration of the treatment. Among PFCAs, only long-chain compounds peaked in foam at the beginning of the treatment. This was consistent with the increase in the sorption affinity to the air–water interface with chain length. The same behavior was observed also in PFSAs by comparing PFHXs, PFHpS and PFOS. The fraction of PFCAs still in the leachate after 40 min of treatment was found to decrease with chain length, with PFSAs showing a similar trend. PFAS removal significantly increased with soil particle size, ranging from 48.2 ± 3.2% (fraction < 0.063 µm) to 64.1 ± 1.9% (fraction > 2 mm). Final mass balance analyses detail PFAS distribution among soil, leachate, and foam, providing valuable information for the additional treatment required to destroy the PFAS load extracted from the contaminated soil. Full article