Search Results (296)

Per- and polyfluoroalkyl substances (PFAS) are persistent, chemically stable compounds widely used in daily life. Perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), and perfluorooctanesulfonic acid (PFOS) were identified as the most relevant PFAS due to their prevalence and toxicity. This study aimed to investigate the immunotoxic mechanisms of a mixture of these PFAS using an in silico approach. Comparative Toxicogenomic Database (CTD), GeneMANIA, CytoHubba (Cytoscape), ToppGene Suite, and Metascape were used for the analysis. A total of 65 immune-related genes were identified as common to all four PFAS, with IFNG, TNF, IL1B, IL6, TYK2, CD3E, CASP8, VAV1, ARHGAP4, and CARD11 emerging as key hub genes. CTD phenotype analysis indicated immune dysregulation, with decreased humoral and adaptive immune responses in humans and tissue-specific modulation of B- and T-cell activity in mice, while no immune-related phenotypes were observed for PFNA. Network analysis identified functional modules associated with apoptotic and immune signaling, endothelial cell migration and angiogenesis, and shared inflammatory and viral response pathways. Disease enrichment analysis associated PFAS with autoimmune disorders (rheumatoid arthritis, asthma), metabolic conditions, and cardiovascular diseases (experimental diabetes, hypertensive disease). These results highlight PFAS involvement in immune modulation, cytokine signaling, and disease susceptibility. Full article

Endocrine-disrupting chemicals (EDCs) are important environmental risk factors for urogenital malignancies, but the shared molecular mechanisms underlying their carcinogenic effects remain poorly understood. Here, we systematically investigated the common pro-tumorigenic mechanisms of 12 prevalent EDCs, including anthracene, benzo[a]pyrene (BaP), bisphenol A, clofenotane, di(2-ethylhexyl) phthalate, diazinon, dibutyl phthalate, glyphosate, malathion, perfluorooctanoic acid, polychlorinated biphenyls, and triclosan, across four urogenital cancers, including bladder cancer (BLCA), renal cell carcinoma (RCC), prostate adenocarcinoma (PRAD), and testicular germ cell tumor (TGCT). By integrating network toxicology and protein–protein interaction analysis, we identified shared hub targets linking EDC exposure to tumor progression. EGFR and CASP3 were identified as core targets in BLCA, EGFR and CASP9 in RCC, and CASP3, ESR1, and EGFR in PRAD, whereas KIT emerged as a broadly relevant target in TGCT. Molecular docking and molecular dynamics simulations supported the stable binding of EDCs to these targets. Among the predicted interactions, BaP showed strong binding affinity for CASP9 (ΔG = −9.8 kcal/mol) and was therefore selected for experimental validation. Analysis of TCGA data showed that elevated CASP9 expression was significantly associated with poorer overall survival in patients with RCC. In 786-O and ACHN cells, chronic exposure to an environmentally relevant concentration of BaP significantly increased CASP9 protein stability without altering its mRNA expression, suggesting post-transcriptional regulation. Collectively, these findings identify shared molecular targets of EDCs across urogenital cancers and provide new mechanistic insight into EDC-driven tumor progression, prioritizing potential biomarkers and therapeutic targets for environmentally related malignancies. 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

To achieve efficient removal and defluorination of perfluorooctanoic acid (PFOA), a visualized micro-scale fused quartz tube reactor (FQTR) was constructed to systematically investigate sub/supercritical water oxidation (SCWO) processes. Under operating conditions of 200–400 °C and 8–27.3 MPa, PFOA underwent rapid degradation with near-complete conversion. The incorporation of γ-MnO₂ markedly enhanced the PFOA degradation at low temperature and achieved faster fluorine removal. At the conditions of 300 °C, 40 min, O/C ratio (oxygen-to-carbon molar ratio) = 1.5, and pH = 7, the degradation and defluorination efficiencies increased by 12.56% and 15.21%, respectively, compared with the non-catalytic system. This enhancement is primarily attributed to the efficient activation of H₂O₂ by γ-MnO₂, which promotes the breaking of C–F bond and accelerates the converting of PFOA into CO₂ and fluoride ions. The SEM, Raman and leaching experiment results demonstrated that γ-MnO₂ exhibits excellent structural stability and reusability. Furthermore, density functional theory (DFT) calculations were performed to identify potential reactive sites and elucidate degradation pathways at the molecular level, providing mechanistic support for the experimental observations. Overall, the γ-MnO₂-catalyzed SCWO exhibits excellent degradation and defluorination performance for PFOA removal, providing useful insight into the treatment of fluorinated wastewater. 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

Widespread exposure to per- and polyfluoroalkyl substances (PFAS) is a growing public health concern, but its link to muscle damage remains largely unexplored. As PFAS exposure is associated with liver dysfunction, which is an established risk factor for muscle damage, we examined their associations and potential mediating pathways. A total of 1261 participants were recruited from Guangdong province, China, from November 2018 to August 2019 and examined for muscle mass, strength, serum PFAS levels, and biomarkers of liver function. The key results demonstrated significant positive associations between serum PFAS exposure and sarcopenia risk. Specifically, a per ln ng/mL increase in linear perfluorooctane sulfonate (PFOS), branch PFOS, and perfluorooctanoic acid (PFOA) was associated with adjusted odds ratios of 2.32 (95% CI: 1.77 to 3.00), 2.18 (95% CI: 1.67 to 2.90) and 3.01 (95% CI: 1.96 to 4.70), respectively. Analysis of PFAS mixtures via the BKMR model revealed a linear dose–response relationship of sarcopenia, with PFOS and PFOA being the primary contributor. Importantly, mediation analyses showed that liver function biomarkers served as significant mediators of the PFAS–sarcopenia association. Notably, liver synthesis function markers (albumin and globin) mediated a substantial proportion of the association, ranging from 3.48% to 82.42%, whereas liver injury markers (aspartate aminotransferase and gamma-glutamyl transferase) accounted for only 1.54% to 15.44%. This study underscores the need to be aware of the increased risk of muscle damage associated with PFAS exposure, which may primarily operate through liver function abnormalities. Full article

The performance of a sequencing batch biofilter granular reactor (SBBGR), followed by a dual media granular activated carbon (GAC) column, was evaluated in terms of its ability to remove selected per- and polyfluoroalkyl substances (PFAS) from landfill leachate. The results show that the SBBGR achieved an overall reduction of 51%, with the preferential removal of long-chain PFAS, while short-chain PFAS were only partially removed. Subsequent GAC treatment exhibited compound-specific breakthrough behavior, which was governed by chain length. Short-chain PFAS (e.g., perfluorobutanoic acid) exhibited rapid bed volumes at 50% breakthrough (BV₅₀ ≈ 88), whereas long-chain PFAS (e.g., perfluorooctanoic acid and perfluorooctanesulfonic acid) were substantially more retained (BV₅₀ ≈ 446 and 361, respectively), with perfluorohexanesulfonic acid and perfluorodecanoic acid failing to reach BV₅₀ within the monitored period. Mass balance analysis showed that the hybrid GAC column captured ~73% of the influent PFAS mass. This resulted in >80–95% retention of long-chain PFAS and <40% retention of short-chain PFAS. Although long-chain PFAS were preferentially adsorbed, mobile short-chain species dominated residual effluent loads. These findings highlight the need for optimized contact times or dual-media strategies to control the breakthrough of short-chain PFAS. Full article

Perfluorooctanoic acid (PFOA) is an environmentally persistent chemical that enters the gastrointestinal tract (GIT) via the food chain, posing a harmful, long-term threat to human health. In response to this challenge, research on the PFOA-GIT interaction is thriving. Currently, studies on the effect of PFOA on the epithelial cells of the GIT and those on its influence on the microbial community are often implemented separately, and less attention has been paid to the combinational effects of the chemical, the gut microbiome and metabolome. In the present study, we co-cultured fecal samples from healthy adults aged 25–70 in the ex vivo SIFR^® simulator, adding PFOA at 10 mg/L to represent the accumulated effects of long-term exposure. The results obtained from bacterial cell counting by flow cytometry and shotgun metagenomic sequencing revealed that PFOA was broadly disruptive to the microbiome and that Pseudomonadota emerged as the dominant phylum by replacing Bacteriodota and Bacillota, including key members of short-chain fatty acid-producing groups. Bacterial culture media with and without PFOA were collected and used in human colonoid cell culture for TEER and transcription measurement. It was shown that the PFOA-impacted microbial culture had stronger effects on the cell’s protective functions, in terms of tissue junction tightening, mucin biosynthesis, and immune response, than either untreated bacterial culture or PFOA alone. The results point out the possibility that the combination of PFOA and PFOA-impacted bacterial metabolites more strongly induces a change in epithelial cells’ protective function than either one alone. 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

This study evaluated the impact of a fire at a plastic recycling plant in the suburbs of Osijek on the concentrations of per- and polyfluoroalkyl substances (PFAS) in home-produced eggs (HPE) collected from nearby settlements exposed to smoke. The assessment was conducted over three time periods following the fire. Commercial eggs from supermarkets and HPE from northwestern Croatia were also analyzed. Thirteen out of 30 compounds were quantified. In both HPE groups—the one closer to and more exposed to smoke (Zone A) and the one farther from fire (Zone B)—linear perfluorooctane sulfonic acid (L-PFOS) showed the highest detection frequency (91–100%). The highest mean concentrations of L-PFOS and the sum of the four main PFAS (∑4PFAS: PFOS, perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS)), at 1.33 μg/kg, were measured in HPE from Zone A one month after the fire. In Zone B, a lower total ∑4PFAS of 0.93 μg/kg was detected. After eight months, concentrations of all quantified compounds decreased. The sums of ∑4PFAS decreased to 0.41 μg/kg (A) and 0.37 μg/kg (B), respectively. Concentrations are higher than those from northwestern Croatia and the previously determined national average. Weekly intakes of ∑4PFAS exceeded the tolerable weekly intake for toddlers and children even eight months after the fire. Full article

The molecular mechanism underlying male reproductive toxicity associated with Perfluorooctanoic acid (PFOA), a persistent environmental endocrine disruptor (EDC), has not yet been fully elucidated. Six-week-old male C57BL/6 mice were treated with PFOA by oral gavage at 0, 1.25, 5, 10, and 20 mg/kg/day for 35 days to explore its toxic effects on the male reproductive system and the underlying mechanisms. Analyses of semen quality, testicular histopathology, and blood–testis barrier (BTB) integrity revealed that PFOA caused dose-dependent structural and functional damage to the BTB, leading to markedly reduced semen quality. Based on transcriptomic sequencing and differential gene enrichment analysis, the glycolytic pathway was identified as a key regulatory target for PFOA-induced damage to the reproductive system. Further validation revealed that PFOA exposure inhibited glycolysis-related enzymes (Hexokinase 1 (HK1), Glucose Transporter 1 (GLUT1), and Lactate Dehydrogenase A (LDHA)), reduced lactate production and ATP synthesis, lowered Pan-Kla and H3K18la levels, and diminished H3K18la enrichment at the Hk1, Glut1, and Ldha promoters, whereas exogenous sodium lactate reversed these changes. This study is the first to identify the “glycolysis–lactate–H3K18la” chain as a key regulator in PFOA-induced BTB damage and spermatogenesis impairment, offering a new theoretical foundation for understanding EDC-induced male reproductive toxicity. Full article

Electrochemical oxidation (EO) possesses numerous advantages and great potential for organic pollutant degradation. However, traditional plate anodes for EO are limited by pollutant mass transfer, leading to low oxidation efficiency and high energy consumption. Herein, a three-dimensional (3D) polyacrylonitrile-based carbon fiber brush (PAN-CFB) anode was employed to enhance mass transfer and improve oxidation efficiency. The oxidation capacity of the PAN-CFB anode was compared with those of boron-doped diamond (BDD) and Ti/IrO₂-Ta₂O₅ plate anodes using oxalic acid (OA), phenol, and perfluorooctanoic acid (PFOA) as target pollutants, respectively. Experimental results demonstrated that the 3D PAN-CFB anode exhibits superior direct oxidation capacity compared to BDD and the Ti/IrO₂-Ta₂O₅ plate anode in degrading OA, which is attributed to the significantly enhanced mass transfer of OA toward the brush anode surface. Under a constant current of 400 mA for 240 min, the total organic carbon (TOC) removal from 50 mmol/L OA reached 90.5%, 57.5% and 6.6% for PAN-CFB, BDD and the Ti/IrO₂-Ta₂O₅ anode, respectively, and the energy consumption followed the order of PAN-CFB (5.5~8.9 kWh/kg_TOC) < BDD (11.2~19.3 kWh/kg_TOC) < Ti/IrO₂-Ta₂O₅ (76.1~120.7 kWh/kg_TOC). However, the 3D PAN-CFB anode exhibited poor stability at high potential and failed to promote phenol and PFOA degradation due to the weak direct oxidation capacity toward the two pollutants and the poor generation capacity of reactive oxygen species, associated with its low oxygen evolution potential. Therefore, future efforts should focus on developing stable 3D brush electrodes with a higher oxygen evolution potential to enable non-selective oxidation of a broader range of pollutants. Full article

Environmental contaminants pose threats to exposed organisms and negatively impact the nervous, cardiovascular, immune, and reproductive systems. Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals that are ubiquitous in the environment. Given that mixtures of environmental contaminants have the potential to exacerbate toxicity, we reviewed the current literature on pesticides, microplastics, or metal exposure in combination with PFAS on aquatic vertebrates and invertebrates. The objectives were to evaluate the toxicological effects of mixtures of the selected contaminants with PFAS on aquatic organisms to better understand biological responses in animals. Based on our review, data suggest that PFAS can modify the toxicity of co-occurring pollutants. For example, synergistic effects on toxicity include chlorpyrifos + perfluorohexanoic acid (PFHxA), which increased reactive oxygen species (ROS) and upregulated neurotoxicity-related genes in zebrafish, and perfluorooctanoic acid (PFOA) + atrazine, which increased the presence of malformations and oxidative stress. However, antagonistic interactions were also observed, for example, reduced herbicide toxicity in PFOA + 2,4-dichlorophenoxyacetic acid (2,4-D) mixtures. PFAS combined with microplastics often intensified oxidative stress and developmental or reproductive effects, though polyethylene microplastics attenuated perfluorooctane sulfonic acid (PFOS)-induced immunotoxicity in fish like seabass. Interactions with metals also varied, with copper and cadmium enhancing oxidative stress while mercury mixtures with PFAS showed antagonism, underscoring the complexity of mixture effects in real environments. A computational approach demonstrated that PFOS can engage in intermolecular interactions with pesticides, microplastic monomers, and metals, suggesting chemical-level effects that could modify toxicity or bioavailability. Future studies should focus on elucidating the mechanisms underlying these complex interactions, investigating effects at different trophic levels and in a broader range of species, and should consider environmentally relevant mixtures. Full article

The persistence of per- and polyfluoroalkyl substances (PFASs) in aquatic environments requires efficient and sustainable treatment technologies. In this study, the electrochemical degradation of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) was investigated using a grid-shaped Ti₄O₇ Magnéli-phase anode under electro-oxidation (EO) and electro-oxidation coupled with electro-Fenton (EO-EF) conditions. Structural characterization confirmed the predominance of Ti₄O₇ in the electrode material. At an initial concentration of 2 ppm, PFOS was rapidly and almost completely removed under both EO and EO-EF, whereas PFOA exhibited slower degradation kinetics, identifying it as the kinetically limiting compound. Coupling EO with electro-Fenton mainly enhanced the degradation kinetics, particularly for PFOA, while final removal efficiencies remained comparable. The influence of initial concentration was further examined, showing that lowering the PFOA concentration to 0.2 ppm, representative of environmentally relevant levels, enabled nearly complete removal within 300 min. Fluoride ion monitoring under optimized EO-EF conditions confirmed partial defluorination, demonstrating that PFOA removal is accompanied by C-F bond cleavage. These findings highlight the respective roles of EO and EO-EF processes and support the potential of Ti₄O₇-based anodes for energy-competitive PFAS remediation. Full article

Background: Per- and polyfluoroalkyl substances (PFAS) represent a large class of synthetic fluorinated compounds characterized by highly stable carbon–fluorine bonds that confer exceptional environmental persistence and bioaccumulative properties. Although regulatory measures have restricted the production of several PFAS, including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), their environmental persistence continues to maintain widespread human exposure, while newly introduced replacement compounds raise additional toxicological concerns. Notably, the recent evidence demonstrating PFAS-induced alterations in key cardiac ion channel activity and electrocardiographic parameters suggest potential electrophysiological mechanisms that may contribute to arrhythmogenesis and cardiac arrhythmias including the most frequent one, atrial fibrillation (AF). Methods: We conducted a narrative literature review of experimental, epidemiological, and mechanistic studies investigating and reporting the cardiovascular, electrophysiological, and potential arrhythmogenic effects of PFAS. Results: Available evidence indicates that PFAS exposure is associated with alterations in cardiac electrophysiology, including modulation of ion channel activity (notably sodium, calcium, and potassium channels), disruption of calcium handling, and changes in electrocardiographic parameters such as QT interval prolongation, which are key contributors to arrhythmogenesis and AF. Conclusions: This review highlights the need for improved understanding of PFAS-induced electrophysiological alterations, to clarify the role of PFAS in cardiac arrhythmias including AF. Full article