Current state of knowledge of environmental occurrence, toxic effects, and advanced treatment of PFOS and PFOA

PFOS causes lysosomes-regulated mitochondrial fission through TRPML1-VDAC1 and oligomerization of MCU/ATP5J2

Perfluorooctane sulfonate (PFOS), a listed persistent organic pollutant, poses risks to human health and is closely linked to chronic metabolic diseases. Although the role of mitochondrial fission in these diseases has garnered attention, whether and how PFOS induces mitochondrial fission remains obscure. Here, we found that PFOS induced mitochondrial fission, as demonstrated by the fragmentation of mitochondria and the upregulation of dynamin-related protein 1 (DRP1), phospho-DRP1 and mitochondrial fission protein 1 (FIS1) in human hepatocytes MIHA and mice liver. Blocking the calcium transfer from lysosomes to mitochondria that was executed by transient receptor potential mucolipin 1 (TRPML1) of lysosomes and voltage-dependent anion channel 1 (VDAC1) of mitochondria, did not affect PFOS-induced mitochondrial fission. In contrast, knockdown of TRPML1 or VDAC1 reversed this process. Knockdown of mitochondrial calcium uniporter (MCU), rather than inhibiting its activity, effectively alleviated PFOS-induced mitochondrial fission. Additionally, PFOS increased MCU oligomers without affecting MCU monomer. Inhibiting autophagy reversed the MCU oligomerization. Further investigation unveiled the interactions of MCU with VDAC1, TRPML1, mitochondrial Fo complex subunit F2 (ATP5J2) and DRP1 in PFOS-exposed mice liver and MIHA cells. We also discovered that knockdown of ATP5J2 alleviated PFOS-induced mitochondrial fission. Ulteriorly, PFOS upregulated ATP5J2 that underwent oligomerization. Knockdown of MCU reversed the increase in ATP5J2. Our study uncovers the presence and molecular basics of lysosomes-regulated mitochondrial fission under PFOS exposure, explains the regulatory pathways on MCU and ATP5J2 oligomerization and their pivotal roles in mitochondrial fission, highlighting the involvement of mitochondrial fission in PFOS-related health risks.

Unveiling the nexus between environmental exposures and testicular damages: revelations from autophagy and oxidative stress imbalance

Recent evidence consolidates the deleterious impact of environmental exposure on testicular damage. Environmental exposures can instigate testicular toxicity, causing damage to the Sertoli-Sertoli cell-mediated blood-testis barrier (BTB) integrity, alterations in hormone levels orchestrated by aberrant Leydig cells, and disruption of spermatogenesis. Despite diverse study designs and methodologies, a consensus is emerging on how environmental factors induce oxidative stress by elevating ROS levels, affecting autophagy through pathways such as the ROS-mediated mTOR signaling pathway, ultimately culminating in testicular damage. This review synthesizes existing literature on how environmental exposures, including metals, air pollutants, industrial contaminants, and pesticides, disturb testicular homeostasis via autophagy-mediated oxidative stress, highlighting recent significant advancements. It also explores interventions like antioxidant support and autophagy regulation to alleviate testicular damage. These findings underscore the importance of elucidating the mechanisms of autophagy influenced by environmental exposures in disrupting the equilibrium of oxidative stress, identifying potential drug targets, and establishing a groundwork for enhancing future treatments and clinical management of testicular injuries.

PFOS and Its Substitute OBS Cause Endothelial Dysfunction to Promote Atherogenesis in ApoE-/- Mice

Perfluorooctanesulfonate (PFOS), an emerging contaminant with widespread concern, has been associated with the pathogenesis of atherosclerosis (AS). As a substitute for PFOS, sodium p-perfluorous nonenoxybenzenesulfonate (OBS) is extensively utilized in various applications and detected in human blood. However, its potential health risk in AS remain unclear. In this study, we investigated the comparative impacts of PFOS and OBS on endothelial dysfunction and atherogenesis. In the in vivo study, Apolipoprotein E knockout (ApoE-/-) mice were exposed to 0.4 or 4 mg/L PFOS/OBS for 12 weeks. We found that dyslipidemia developed more rapidly in the OBS-exposed mice than in the PFOS-exposed mice. PFOS exhibited a higher enrichment capacity in both blood and aortic tissues than OBS. Remarkably, OBS induced a more pronounced inflammatory response and caused a more significant disruption of the endothelial barrier in the aorta of ApoE-/- mice compared to PFOS. In vitro experiments showed that OBS, at the same exposure concentrations and durations as PFOS (0.1-20 μmol/L, 48 h), more effectively inhibited cell viability of human umbilical vein endothelial cells (HUVECs), caused higher levels of lactate dehydrogenase (LDH) release, and enhanced cell adhesion between HUVECs and monocytes. Both PFOS and OBS were found to activate the NF-κB signaling pathway and upregulate the expression of inflammatory factors. Notably, the use of OBS, but not PFOS, was shown to disrupt cell junctions and increase endothelial permeability by activating the MAPK/ERK signaling pathway. Our findings suggest that OBS may lead to endothelial dysfunction and have a greater impact on AS compared to PFOS, presenting significant health risks in cardiovascular diseases.

Does exposure to zinc, methomyl, and perfluorooctanoic acid alter feeding behavior on MUG® in the freshwater amphipod Gammarus fossarum?

Feeding rate alteration is one of the first observed responses when animals are exposed to toxic stress and is recognized as a relevant tool for studying chemical compounds toxicity. However, food substrates that are currently used for ecotoxicity tests are not always easily available compared with referenced products. Using the European freshwater amphipod Gammarus fossarum, we here propose a standardized food substrate fabricated with referenced ingredients: the MUG® (meal unit for gammarid) for ecotoxicity tests. To investigate the suitability of using MUG to study behavioral response of amphipods to toxic stress, in laboratory-controlled conditions, we explored whether three chemical compounds belonging to different families of contaminants (zinc [Zn], a metal; methomyl [MT], an insecticide; and perfluorooctanoic acid [PFOA], a per-/poly-fluoroalkyl substance) could affect gammarids feeding rates on MUG. First, we explored the effects of 7-day exposure to different concentrations of each contaminant alone. Although PFOA did not affect feeding rate, Zn induced feeding behavior on MUG at a lower concentration but inhibited food consumption at higher ones, whereas MT decreased feeding rate with increased concentration. Then, we explored effects when gammarids were exposed during 7 days to mixtures of molecules in pairs. No effect of mixtures was observed on MUG consumption compared with the control group. Observed effects of binary mixtures were also compared with predicted values based on additive effects of contaminants. Both Zn/MT and Zn/PFOA mixtures inhibited feeding behavior compared with predictions, resulting in feeding rate values similar to controls. Overall, our study supports that MUG represents a promising standardized food substrate for evaluating substance effects on amphipod behavior during laboratory ecotoxicological bioassays.

Molecular Mechanism of Perfluorooctane Sulfonate-Induced Lung Injury Mediated by the Ras/Rap Signaling Pathway in Mice

Perfluorooctane sulfonate (PFOS), a persistent organic pollutant, has raised significant public health concerns because of its widespread environmental presence and potential toxicity. Epidemiological studies have linked PFOS exposure to respiratory diseases, but the underlying molecular mechanisms remain poorly understood. Male C57 BL/6J mice were divided into a control group receiving Milli-Q water, a low-dose PFOS group (0.2 mg/kg/day), and a high-dose PFOS group (1 mg/kg/day) administered via intranasal instillation for 28 days. Lung tissue transcriptome sequencing revealed significantly enriched differentially expressed genes in the Ras and Rap signaling pathways. Key genes including Rap1b, Kras, and BRaf as well as downstream genes, such as MAPK1 and MAP2K1, exhibited dose-dependent upregulation in the high-dose PFOS exposure group. Concurrently, the downstream effector proteins MEK, ERK, ICAM-1, and VEGFa were significantly elevated in bronchoalveolar lavage fluid (BALF). These alterations are mechanistically associated with increased oxidative stress, inflammatory cytokine release, and pulmonary tissue damage. The results indicated that PFOS-induced lung injury is likely predominantly mediated through the activation of the Rap1b- and Kras-dependent BRaf-MEK-ERK axis. These findings highlight the critical role of Ras/Rap signaling pathways in PFOS-associated respiratory toxicity and underscore the need to develop therapeutic interventions targeting these pathways to mitigate associated health risks.

Additive effect of Bisphenol A and Pefluoro-sulphoctanoic acid exposure at subacute toxic levels, on a murine model of sertoli cell

PURPOSE

Endocrine disruptors (EDs) interfere with the endocrine system leading to health consquences and reproductive derangements. Most EDs are environmental pollutants whose risk evaluation is hampered by the simultaneous exposure to a number of chemicals. Here we investigated the possible mechanistic involvement of Sertoli cells, the nurse cell population in the seminiferous tubule, in the reproductive toxicity of Bisphenol A (BPA) and perfluoro-octane sulphonate (PFOS), two acknowledged EDs, at recognized subacute toxic levels.

METHODS

Mouse Sertoli cell line TM4 were exposed for 24 h to 40 ng/mL BPA or 30 ng/mL PFOS or their association. Cell proliferation was measuerd by MTT assay. Cell apoptosis was evaluated with Annexin-V/propidium iodide staining. Protein expression analysis was peformed by western blotting.

RESULTS

Compared to unexposed controls (100.0 ± 3.5%), cells exposed to BPA (79.5 ± 3.5%) or PFOS (76.0 ± 7.9%) showed reduced survival rate (P < 0.001 vs control). The exposure to the mixture of BPA and PFOS was associated with a further reduction of cell survival (63.9 ± 7.2%, P < 0.001 vs control) and an increase of the percentage of apoptotic cells (13.7 ± 4.6% control, 40.3 ± 13.5% BPA, PFOS 28.7 ± 5.6%, 67.1 ± 19.6% BPA + PFOS P = 0.001 vs control; P = 0.022 vs BPA). The exposure to the combination of BPA and PFOS was associated with Akt-signaling pathway activation and with the downstream caspase 3 cleavage. In addition, the exposure to the combination of BPA and PFOS was associated with NF-κB activation and increased expression of FasL.

CONCLUSION

Subacute toxic levels of BPA and PFOS display additive effects on Sertoli cell apoptosis with the possible involvement of FasL-dependent germ cell apoptosis.

Holistic assessment of chemical and biological pollutants in a Mediterranean wastewater effluent-dominated stream: Interactions and ecological impacts

The discharge of treated wastewater from wastewater treatment plants (WWTPs) into river systems is a significant source of pollution, introducing a range of chemical and biological pollutants that impact the chemical and ecological quality status of rivers. This study evaluates the effect of a secondary treated wastewater effluent on the Onyar River, in the northeast of Spain. Water and biofilm samples were collected at one upstream and four downstream sampling points (up to 2.8 km from the discharge point) across four seasons. A wide array of pollutants, including metals, pharmaceuticals, microplastics (MPs), per- and polyfluoroalkyl substances (PFAS), antibiotic resistance genes (ARGs), among other emerging pollutants, were detected downstream, with significant differences between upstream and downstream concentrations. Our results show that WWTP discharge also altered biofilm microbiome composition and ARGs presence, being these changes distinguishable from seasonal variations. Nevertheless, a partial recovery further downstream (525 m) was observed for biofilm microbiome and ARGs composition. These findings highlight the value of microbiome analysis in assessing wastewater impacts on river ecosystems and emphasize the need for further research to improve pollutant attenuation and biofilm recovery strategies in river streams.

Destruction of perfluorooctanoic acid (PFOA) and perfluorooctadecanoic acid (PFOcDA) by incineration: Analysis of the by-products and their characteristics

Per- and polyfluoroalkyl substances (PFAS), which are considered an international problem due to their persistence in the environment, need to be properly treated in the end. In the destruction method by incineration, basic data are required to quantify the destruction characteristics of the target substance and the temperature-dependent behavior of its by-products. In this study, we conducted incineration tests targeting perfluorooctanoic acid (PFOA) and perfluorooctadecanoic acid (PFOcDA). The tests were conducted at temperatures ranging from 450 °C to 1000 °C in a pure air atmosphere, with a residence time of 2 s. The incineration tests at 850 °C achieved a destruction efficiency (DE) of 99.999% for both PFOA and PFOcDA. The DE significantly decreased at temperatures below 700 °C. Various by-products were identified during these tests, including short- and long-chain carbon compounds with ether bonds. Byproducts such as PFOA and polyfluoroalkyl ether carboxylic acids (PFECAs) were produced during the low-temperature incineration of PFOcDA. The amount of by-products produced increased as the temperature decreased, but short-chain by-products increased at incineration temperatures from 450 to 700 °C. The capture media for the by-products varied depending on the carbon chain length of the PFCAs. The proportion captured by glass filters, adsorbents, and sodium hydroxide increased sequentially from long-to short-chain compounds. An examination of the distribution patterns of PFCAs across the different media revealed their predominant presence in the exhaust gas. Sufficient incineration at temperatures above 850 °C is considered necessary for effective destruction of PFOA and PFOcDA, including their by-products.

Identification of emerging contaminants in greywater emitted from ships by a comprehensive LC-HRMS target and suspect screening approach

The increase in maritime traffic has led to substantial greywater discharges into the marine environment. Greywater, originating from sinks, showers, kitchen, and laundry facilities, contains a wide array of chemical contaminants influenced by on-board activities, ship size, and management practices. The lack of comprehensive regulations for greywater management, along with limited research on its chemical composition, highlights the need to characterize these waste streams. This study is one of the first to provide a comprehensive characterization of greywater samples from ships using advanced liquid chromatography coupled to high-resolution-mass-spectrometry (LC-HRMS) strategies, including wide-scope target and suspect screening. The target analysis detected 86 compounds, such as pharmaceuticals, stimulants, tobacco and food-related products, personal care products, UV filters, surfactants, perfluoroalkyl compounds, plasticizers, and flame retardants, many of which are rarely measured in routine monitoring programs. Furthermore, 11 additional compounds were tentatively identified through suspect screening. A novel scoring system further highlighted 25 priority compounds posing ecological risks to marine ecosystems, including pharmaceuticals such as tapentadol, dextrorphan, citalopram, or irbesartan. This study emphasizes the significant introduction of chemicals at μg L-1 levels through greywater discharges, underscoring the urgent need for improved management practices to mitigate ecological risks to the marine ecosystem.

Migration characteristics and toxic effects of perfluorooctane sulfonate and perfluorobutane sulfonate in tobacco

Perfluorooctane sulfonate (PFOS) and its new substitute, perfluorobutane sulfonate (PFBS), are increasing in concentration in the environment annually, and their toxicity cannot be ignored. With an increasing amount of PFOS and PFBS entering the environment, especially into farmland soil, it is very likely to pollute tobacco-planting soil. Therefore, we chose tobacco (Nicotiana tabacum L.) as the test organism. Through the analysis of migration characteristics, we found that PFOS (0.82) is more likely to migrate within tobacco plants than PFBS (0.42). Pot experiments showed that PFOS has a more obvious inhibitory effect on the growth of tobacco. Further investigations revealed that PFOS induces oxidative stress reactions in tobacco and stimulates the increase in the activities of enzymes such as superoxide dismutase (SOD) and catalase (CAT). In addition, both PFOS and PFBS inhibit the expression of genes related to the synthesis of auxin and aroma substances in tobacco. In particular, under the exposure of 10 mg/kg PFOS, the inhibition rates are as high as 88.53 % and 92.32 % respectively. The results of this study compared the differences in toxicity between PFOS and PFBS, and provided a theoretical reference for the behavioral characteristics of new per-polyfluoroalkyl substances (PFASs) in the environment and their potential risks to the ecological environment.

Impacts of hexafluoropropylene oxide tetrameric acid (HFPO-TeA) on neurodevelopment and GABAergic signaling in zebrafish larvae

Hexafluoropropylene oxide oligomer acids (HFPOs), an emerging environmental pollutant, are increasingly utilized in the manufacture of fluorinated synthetic materials as a substitute for traditional perfluorooctanoic acid (PFOA), resulting in a corresponding rise in detection rates in aquatic environments, which may present inherent safety hazards to ecosystems and public health. However, few data are available on the issue of their toxicity and mechanism. This study aimed to investigate the potential toxic effects of hexafluoroepoxypropane tetrameric acid (HFPO-TeA), a typical HFPO, on the early developmental stages of zebrafish larvae. It revealed that HFPO-TeA exposure resulted in significant detrimental effects, including adverse impacts on general morphological characteristics, such as eye area, heart rate, and swimming bladder, in zebrafish embryos and larvae. Targeted metabolomics and transcriptomics inquiries clarified that HFPO-TeA exposure reduced the levels of the neurotransmitter gamma-aminobutyric acid (GABA) and downregulated the expression of genes related to the GABA pathway. Simultaneously, transgenic zebrafish exhibited that exposure to HFPO-TeA impedes the growth of GABAergic neurons. Moreover, the molecular docking analysis indicated that GABAA receptors might be the potential targets of HFPO-TeA. Taken together, the current data highlights that the HFPO-TeA might not be safe alternatives to PFOA. This study presented a model for HFPO-TeA-induced neurotoxicity in developing zebrafish that can aid in ecological risk assessments.

Mechanistic insights into adsorption-desorption of PFOA on biochars: Effects of biomass feedstock and pyrolysis temperature, and implication of desorption hysteresis

Adsorptive removal of the emerging organic pollutant perfluorooctanoic acid (PFOA) from contaminated water using biochar is a promising cost-effective approach. To determine the stability of PFOA adsorption on biochar, the thermodynamic analysis of the adsorption-desorption behavior is essential. This study comprehensively investigated the adsorption and desorption of PFOA on biochars derived from maple sawdust, peanut shells and corn stalks, pyrolyzed at peak temperatures of 400, 600 and 800 °C. The findings indicated that the micropore volume of the biochars was key to PFOA adsorption, with peanut shell biochar produced at 800 °C showing the highest adsorption capacity of 16.75 mg/g, attributed to its larger micropore volume (0.22 m3/g). Thermodynamic analysis showed that the negative values of ∆G0 of PFOA adsorption ranged from -2.24 to -5.38 kJ/mol, confirmed that the process was spontaneous and involved physical pore-filling. However, the close similarity between the adsorption and desorption isotherms, coupled with a low hysteresis coefficient, clarified that the PFOA adsorption was unstable and prone to desorption. The thermodynamic insights from this study highlighted that lignin-rich biochar produced at high temperature with high micropore content was very favorable for the effective adsorptive removal of PFOA, while the long-term adsorption stability should not be overlooked in the remediation applications.

Prenatal exposure to per- and polyfluoroalkyl substances, genetic factors, and autistic traits: Evidence from the Shanghai birth cohort

The epidemiological evidence regarding prenatal PFAS exposure and its interaction with genetic factors on the autistic traits risk is unclear. This study included 1610 mother-child pairs from the Shanghai Birth Cohort (SBC). Ten PFAS were quantified in blood serum collected in the first trimester. Child autistic traits were evaluated at age 4 using a Chinese version of the social responsiveness scale-short form (SRS-SF). We calculated the polygenic risk score (PRS) to evaluate the cumulative genetic effects of autism. Additive interaction models were established to explore whether genetic susceptibility modified the effects of prenatal PFAS exposure. After adjusting for confounders, we found prenatal PFOA exposure was associated with an increased risk of autistic traits in children (OR, 3.05; 95 % CI, 1.14-7.58), and the increased risk associated with PFOA was mitigated among women who reported pre-pregnancy folic acid supplementation. Additionally, an increased risk of autistic traits was observed in children with higher levels of prenatal PFHxS exposure and a high PRS (p for interaction = 0.021). Our findings suggest prenatal PFAS exposure may increase the risk of autistic traits in children, especially in those with a high genetic risk. Further research is warranted to confirm this association and explore the underlying mechanisms.

Thyroid Hormone Neuroprotection Against Perfluorooctane Sulfonic Acid Cholinergic and Glutamatergic Disruption and Neurodegeneration Induction

Background: Perfluorooctane sulfonic acid (PFOS), a widely used industrial chemical, was reported to induce memory and learning process dysfunction. Some studies tried to reveal the mechanisms that mediate these effects, but how they are produced is still unknown. Basal forebrain cholinergic neurons (BFCN) maintain cognitive function and their selective neurodegeneration induces cognitive decline, as observed in Alzheimer's disease. PFOS was reported to disrupt cholinergic and glutamatergic transmissions and thyroid hormone action, which regulate cognitive processes and maintain BFCN viability. Objective/Methods: To evaluate PFOS neurodegenerative effects on BFCN and the mechanisms that mediate them, SN56 cells (a neuroblastoma cholinergic cell line from the basal forebrain) were treated with PFOS (0.1 µM to 40 µM) with or without thyroxine (T3; 15 nM), MK-801 (20 µM) or acetylcholine (ACh; 10 µM). Results: In the present study, we found that PFOS treatment (1 or 14 days) decreased thyroid receptor α (TRα) activity by decreasing its protein levels and increased T3 metabolism through increased deiodinase 3 (D3) levels. Further, we observed that PFOS treatment disrupted cholinergic transmission by decreasing ACh content through decreased choline acetyltransferase (ChAT) activity and protein levels and through decreasing muscarinic receptor 1 (M1R) binding and protein levels. PFOS also disrupted glutamatergic transmission by decreasing glutamate content through increased glutaminase activity and protein levels and through decreasing N-methyl-D-aspartate receptor subunit 1 (NMDAR1); effects mediated through M1R disruption. All these effects were mediated through decreased T3 activity and T3 supplementation partially restored to the normal state. Conclusions: These findings may assist in understanding how PFOS induces neurodegeneration, and the mechanisms involved, especially in BFCN, to explain the process that could lead to cognitive dysfunction and provide new therapeutic tools to treat and prevent its neurotoxic effects.

Non-extractable residues of perfluorooctanoic acid (PFOA) in soil

PER: and polyfluoroalkyl substances have gained increased attention due to their persistence, ubiquitous presence in the environment, and toxicity. We hypothesised that the formation of non-extractable residues [NER] occurs in soils and contributes to the overall persistence of these priority pollutants, and that NER formation is controlled by temperature. To test these hypotheses, we used 14C-labelled perfluorooctanoic acid [PFOA] as target compound, added it to two arable soils (Cambisol, Luvisol), and incubated them at 10 °C and 20 °C in the dark. To support potential co-metabolic decomposition, some samples were additionally fed with glucose to enhance microbial activity. The PFOA residues were then sequentially extracted using 0.01 M CaCl2, followed by accelerated solvent extraction (ASE) with methanol or methanol/acetic acid after 0, 1, 3, 9, 30, 62, and 90 days of incubation. In addition, we monitored the release of 14C into the gas phase as well as [14C]-PFOA-NER after dry combustion and liquid scintillation counting. After 90 days, we found that the [14C]-PFOA content declined in the extraction order of CaCl2 ((bio)available fraction) > ASE (residual fraction) > NER > gas fraction), with most rapid changes occurring in the first 9 days of incubation. NER formation was different in the two soils and reached 5-9% of the applied amount in the Cambisol and Luvisol, respectively. Noteworthy the proportion of 14C-PFOA in the (bio)available fraction remained relatively stable over time at 56-62% of the applied amount, indicating the reversible transfer into this fraction from a bi-exponentially declining residual (ASE) pool. These dissipation patterns were neither influenced by temperature nor by the addition of glucose. We conclude that NER exist for PFOA, but that the majority of PFOA remains in (bio)available form, thus maintaining toxicity and mobility in soil for prolonged periods of time.

Whatever does not kill them makes them stronger: Using quaternary ammonia antimicrobials to alleviate the inhibition of ammonia oxidation under perfluorooctanoic acid stress

Perfluorooctanoic acid (PFOA), benzalkyl dimethylammonium compounds (BAC) and antibiotic resistance genes (ARGs) have negative effects on biological sewage treatment. The performance of nitrification systems under stress of PFOA (0.1-5 mg/L) or/and BAC (0.2-10 mg/L) was explored during 84-day experiments using four sequencing batch reactors, in this study. Low (0.1 mg/L) concentration PFOA had a positive influence on ammonia removal, while medium and high (2 and 5 mg/L) concentrations PFOA caused severe inhibition. Meanwhile, PFOA stress resulted in the enrichment of ARGs in water (w-ARGs). BAC (0-10 mg/L) had no obvious influence on ammonia removal. However, BAC promoted the reduction of ARGs and the bacterial community was the main participator (48.07%) for the spread of ARGs. Interestingly, the joint stress of PFOA and BAC increased the ammonia-oxidizing bacteria (AOB) activity from 5.81 ± 0.19 and 6.05 ± 0.79 mg N/(g MLSS·h) to 7.09 ± 0.87 and 7.23 ± 0.29 mg N/(g MLSS·h) in medium and high concentrations, compared to single stress of PFOA, which was observed for the first time. BAC could reduce bioavailability of PFOA through competitive adsorption and decreasing sludge hydrophobicity by the lower β-Sheet and α-Helix in tightly bound protein. Furthermore, the joint stress of PFOA and BAC was able to intensify the proliferation of w-ARGs and extracellular ARGs in sludge, and developed the most active horizontal gene transfer mediated by intl1 compared to single stress of PFOA or BAC. The batch tests verified the detoxification capacity of BAC on nitrification under 2.5 mg/L PFOA (48 h exposing), and the maximum alleviation of AOB activity was achieved at BAC and PFOA mass ratio of 2:1. In summary, BAC could be used to alleviate the inhibition of PFOA on ammonia oxidation, providing an efficient and sustainable approach in wastewater treatment.

Microfiltration Membrane Pore Functionalization with Primary and Quaternary Amines for PFAS Remediation: Capture, Regeneration, and Reuse

The widespread production and use of multi-fluorinated carbon-based substances for a variety of purposes has contributed to the contamination of the global water supply in recent decades. Conventional wastewater treatment can reduce contaminants to acceptable levels, but the concentrated retentate stream is still a burden to the environment. A selective anion-exchange membrane capable of capture and controlled release could further concentrate necessary contaminants, making their eventual degradation or long-term storage easier. To this end, commercial microfiltration membranes were modified using pore functionalization to incorporate an anion-exchange moiety within the membrane matrix. This functionalization was performed with primary and quaternary amine-containing polymer networks ranging from weak to strong basic residues. Membrane loading ranged from 0.22 to 0.85 mmol/g membrane and 0.97 to 3.4 mmol/g membrane for quaternary and primary functionalization, respectively. Modified membranes exhibited a range of water permeances within approximately 45-131 LMH/bar. The removal of PFASs from aqueous streams was analyzed for both "long-chain" and "short-chain" analytes, perfluorooctanoic acid and perfluorobutyric acid, respectively. Synthesized membranes demonstrated as high as 90% rejection of perfluorooctanoic acid and 50-80% rejection of perfluorobutyric acid after 30% permeate recovery. Regenerated membranes maintained the capture performance for three cycles of continuous operation. The efficiency of capture and reuse can be improved through the consideration of charge density, water flux, and influent contaminant concentration. This process is not limited by the substrate and, thus, is able to be implemented on other platforms. This research advances a versatile membrane platform for environmentally relevant applications that seek to help increase the global availability of safe drinking water.

Perfluorooctane sulfonate-induced Sertoli cell injury through c-Jun N-terminal kinase: a study by RNA-Seq

Per- and polyfluoroalkyl substances (PFASs) are a family of "forever chemicals" including perfluorooctane sulfonate (PFOS). These toxic chemicals do not break down in the environment or in our bodies. In the human body, PFOS and perfluoroctanoic acid (PFOA) have a half-life (T1/2) of about 4-5 yr so low daily consumption of these chemicals can accumulate in the human body to a harmful level over a long period. Although the use of PFOS in consumer products was banned in the United States in 2022/2023, this forever chemical remains detectable in our tap water and food products. Every American tested has a high level of PFAS in their blood (https://cleanwater.org/pfas-forever-chemicals). In this report, we used a Sertoli cell blood-testis barrier (BTB) model with primary Sertoli cells cultured in vitro with an established functional tight junction (TJ)-permeability barrier that mimicked the BTB in vivo. Treatment of Sertoli cells with PFOS was found to perturb the TJ-barrier, which was the result of cytoskeletal disruption across the cell cytoplasm, disrupting actin and microtubule polymerization. These changes thus affected the proper localization of BTB-associated proteins at the BTB. Using RNA-Seq transcriptome profiling, bioinformatics analysis, and pertinent biochemical and cell biology techniques, it was discovered that PFOS -induced Sertoli cell toxicity through the c-Jun N-terminal kinase (JNK; also known as stress-activated protein kinase, SAPK) and its phosphorylated/active form p-JNK signaling pathway. More importantly, KB-R7943 mesylate (KB), a JNK/p-JNK activator, was capable of blocking PFOS-induced Sertoli cell injury, supporting the notion that PFOS-induced cell injury can possibly be therapeutically managed.NEW & NOTEWORTHY PFOS induces Sertoli cell injury, including disruption of the 1) blood-testis barrier function and 2) cytoskeletal organization, which, in turn, impedes male reproductive function. These changes are mediated by JNK/p-JNK signaling pathway. However, the use of KB-R7943, a JNK/p-JNK activator was capable of blocking PFOS-induced Sertoli cell injury, supporting the possibility of therapeutically managing PFOS-induced reproductive dysfunction.

Maternal PFOS exposure in mice induces hepatic lipid accumulation and inflammation in adult female offspring: Involvement of microbiome-gut-liver axis and autophagy

Perfluorooctane sulfonates (PFOS) are the persistent organic pollutants. In the present study, 0, 0.3, or 3-mg/kg PFOS were administered to pregnant mice from GD 11 to GD 18. The histopathology of liver and intestine, serum and hepatic lipid levels, lipid metabolism related genes, and gut microbiota were examined in adult female offspring. The results suggested that maternal PFOS exposure increased serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and induced F4/80+ macrophage infiltration in adult female offspring, in addition to the elevation of TNF-α and IL-1β mRNA levels in low-dose and high-dose groups, respectively. Furthermore, maternal exposure to PFOS increased serum triglyceride (TG) and hepatic total cholesterol (TC) levels, which was associated with the alteration of the process of fatty acid transport and β-oxidation, TG synthesis and transport, cholesterol synthesis and excretion in the liver. The AMPK/mTOR/autophagy signaling was also inhibited in the liver of adult female offspring. Moreover, changes in gut microbiota were also related to lipid metabolism, especially for the Desulfovibrio, Ligilactobacillus, Enterorhabdus, HT002 and Peptococcaceae_unclassified. Additionally, maternal exposure to PFOS decreased mRNA expressions of the tight junction protein and AB+ goblet cells in the colon, while increasing the overproduction of lipopolysaccharides (LPS) and F4/80+ macrophage infiltration. Collectively, maternal PFOS exposure induced liver lipid accumulation and inflammation, which strongly correlated with the disruption of the gut-liver axis and autophagy in adult female offspring, highlighting the persistent adverse effects in offspring exposed to PFOS.

Crop Contamination and Human Exposure to Per- and Polyfluoroalkyl Substances around a Fluorochemical Industrial Park in China

Due to their significant environmental impact, there has been a gradual restriction of the production and utilization of legacy per- and polyfluoroalkyl substances (PFAS), leading to continuous development and adoption of novel alternatives. To effectively identify the potential environmental risks from crop consumption, the levels of 25 PFAS, including fourteen perfluoroalkyl acids (PFAAs), two precursor substances and nine novel alternatives, in agricultural soils and edible parts of various crops around a fluoride industrial park (FIP) in Changshu city, China, were measured. The concentration of ΣPFAS in the edible parts of all crops ranged from 11.64 to 299.5 ng/g, with perfluorobutanoic acid (PFBA) being the dominant compound, accounting for an average of 71% of ΣPFAS. The precursor substance, N-methylperfluoro-octanesulfonamidoacetic acid (N-MeFOSAA), was detected in all crop samples. Different types of crops showed distinguishing accumulation profiles for the PFAS. Solanaceae and leafy vegetables showed higher levels of PFAS contamination, with the highest ΣPFAS concentrations reaching 190.91 and 175.29 ng/g, respectively. The highest ΣAlternative was detected in leafy vegetables at 15.21 ng/g. The levels of human exposure to PFAS through crop consumption for various aged groups were also evaluated. The maximum exposure to PFOA for urban toddlers reached 109.8% of the standard value set by the European Food Safety Authority (EFSA). In addition, short-chained PFAAs and novel alternatives may pose potential risks to human health via crop consumption.