Environmental Pollution

Perfluorooctane sulfonic acid (PFOS), a per- and polyfluoroalkyl substance (PFAS), is a widespread persistent environmental pollutant that has been implicated in various human health conditions, including infertility and cancer. Here, we investigate the effects of acute exposure to PFOS on human fallopian tube epithelial (FNE) cells that are essential for fertility and increasingly recognized as the origin site for high-grade serous ovarian cancer. We show that acute PFOS exposure changes morphology, arrests proliferation, impairs adhesion, and compromises epithelial integrity of FNE cells. Using transcriptomic profiling of FNE cells exposed to PFOS, we found increased expression of genes associated with stress-response signal transduction, including KRAS, and decreased expression of genes related to cholesterol transport and lipid homeostasis. We show that inhibition of MEK/ERK or cholesterol supplementation rescued changes in cell morphology. Further, we performed membrane fluidity measurements of cells exposed to PFOS and found elevated membrane disorder and fluidity. Our results are consistent with a model in which PFOS perturbs plasma membrane, activates stress-response signaling pathways, and impairs epithelial cell function. These studies establish a framework for understanding the effects of PFAS on cell physiology.

Bats are exposed to a variety of pollutants, including cadmium (Cd), that can impair immune function and potentially increase viral shedding and burden. Despite this, little is known about the impacts of heavy metals on bats. This study aimed to determine the impacts of Cd exposure on bat T and B cell immune responses in naive and coronavirus infected bats and determine the impact of Cd on viral replication in Jamaican fruit bat (JFB; Artibeus jamaicensis) cells. To determine the impact of Cd exposure on adaptive immune responses, splenocyte cultures from naive and BANAL-52 coronavirus infected JFB were treated with 0, 1, and 10 {micro}M Cd and stimulated overnight with concanavalin A. RNA was extracted, a SYBR Green qPCR was used to assess gene expression. To determine if Cd exposure increased viral replication, two JFB kidney cell clones were treated with 0, 1, 10, and 50 {micro}M of CdCl2 overnight and then infected with Cedar virus (CedV). Supernatants were collected and viral titers determined. Several transcripts were upregulated in both naive and virus infected JFB splenocytes treated with Cd. B cell transcripts were significantly upregulated in a dose-dependent manner and T cell transcripts were also increased in Cd treated splenocytes. Assessment of transcripts associated with T cell subsets suggest a predominant Th2 response in Cd treated splenocytes. Viral replication was not significantly different in Cd treated kidney clones compared to the non-treated cells. These studies provide evidence that JFB adaptive immune responses are altered when exposed to low Cd concentrations.

Micro and nanoplastics are pollutants which concentration in different biotopes increases continuously over time, which poses the question of their potential effects on health. In animals, these micro and nanoplastics are recognized as particulate materials and thus handled by macrophages, which are therefore a key cell type to study. Most studies have used an experimental scheme in which the cells are exposed to a single dose of plastics, with a readout made immediately after exposure. However, this classical experimental scheme does not take into account the impact of biopersistence, nor the potential cellular adaptation that may take place when cells are exposed repeatedly to a low dose of plastics. We thus used a repeated exposure scheme, in order to better take into account these phenomena. Within this frame, we compared the macrophages responses to a persistent nanoplastic, i.e. polystyrene nanoparticles and to a biodegradable nanoplastic, i.e. polylactide, by a combination of proteomic and targeted experiments. Our results show that under this repeated exposure scheme, the proteome changes were of a lesser (for PS) or similar (for PLA) extent than under the acute exposure mode, indicating cell adaptation. However, PLA particles induced mitochondrial dysfunction and depression of response to bacterial molecules perceived as danger signals, such as lipopolysaccharide. Polystyrene nanoparticles also induced a slight alteration of the immune functions of macrophages. This indicates harmful effects even in the repeated exposure scheme.

The East Asian region, known for its high levels of human and fishery activities, experiences serious plastic pollution in the marine environment, especially in seawater and along coastlines. Wharf roaches (Ligia spp.) collected from the coast of western Japan frequently ingest expanded polystyrene (EPS), which is then excreted as microplastic through their feces. However, the impact of EPS exposure and ingestion on the gut microbiome of wharf roaches remains unclear. Thus, this study aimed to investigate the effects of EPS ingestion on the gut microbiota of wharf roaches by examining their gut microbiota and gene expression. The expression levels of more than 400 genes, including those associated with xenobiotic metabolism, and the abundance of gut microbial community were altered. Microbial analysis revealed that at least five archaeal types, two to four bacterial types, three to seven eukaryotic types, and three viral types were involved in a correlation network composed of strong associations. Among them, Haloquadratum, Halalkalicoccus, and Methanospirillum (archaea); Volvox (eukaryote); and Varicellovirus and T4-like viruses showed significantly increased abundance. Furthermore, covariance structure analysis indicated that the viruses and methanogens played key causal roles as characteristic factors related to EPS administration. In conclusion, EPS disrupts the intestinal environment of wharf roaches and serves as a potential material for viral activation and methane production. Building on our previous field study that identified wharf roaches as potential indicators of coastal EPS pollution, this study provides novel insights into the ecological impacts of EPS ingestion and consequences of plastic pollution.

Tropical coral reef ecosystems worldwide are being impacted by combined pressures of climate change and human activities that introduce large quantities of nutrients and sediments into coastal areas. In this context, phytoplankton represent a critical link between dissolved inorganic nutrients and coral reef food webs, yet their role in these ecosystems remains understudied. We investigated ecological responses of the summer phytoplankton community of Shiraho Reef (Ishigaki Island, Okinawa, Japan) to nutrient enrichment using field-based microcosm experiments under natural light and temperature conditions in September 2022 and 2023. Treatments included single and combined additions of nitrogen, phosphorus, and silicon. Chlorophyll a (Chl a) concentrations increased after three days under combined nutrient conditions, whereas single-nutrient additions produced limited responses, indicating a strong co-limitation by nitrogen and phosphorus in the reef. Analysis of size-fractionated Chl a revealed shifts from picophytoplankton that typically dominate tropical oligotrophic ecosystems toward larger groups supported by enhanced nutrient availability. Our results show short-term impacts of nutrient enrichment events on phytoplankton size structure and biogeochemical cycling in coral reefs, and highlight the importance of pelagic processes in coral reef carbon dynamics under nutrient-enrichment.

A compact, in-house developed ultraviolet germicidal irradiation (UVGI) system adaptable to static, mobile, or robotic platforms was developed for the effective sterilization of bacteria and fungi using a wireless mode of operation. Under controlled laboratory conditions, its efficacy was evaluated against three representative biofilm-forming pathogens: Bacillus subtilis (Gram-positive, spore-forming, motile bacterium), Escherichia coli K12 (Gram-negative, non-spore-forming, non-motile bacterium), and Candida albicans M-207 (multi-drug-resistant, clinical yeast isolate). Microbial viability following UVGI exposure was assessed using colony-forming unit (CFU) and MTT assays, and morphological alterations were characterized by scanning electron microscopy (SEM). Cultures were exposed to UV-C radiation at distances of 1-5 m for 15-90 min. CFU assay demonstrated 100% kill of all tested organisms at 1 m and 15 min, corresponding to doses of 600.3, 576 & 697.5 mJ/cm{superscript 2}. Although MTT assays indicated residual metabolic activity under the same conditions, CFU results confirmed that surviving cells were unable to proliferate, highlighting the robustness of UV treatment for long-term inactivation. SEM confirmed distinct morphological alterations such as complete destruction of extracellular matrix & reduction in number of cells indicating cell death with increase in UV dose as compared to controls. A dose & time-dependent inactivation of biofilm-forming bacteria & fungi was observed on exposure to UVGI. Therefore, this pilot study validates the effectiveness of the newly developed UVGI surface sterilizer against biofilm-forming bacterial and fungal pathogens. Overall, the system demonstrates proof-of-concept efficacy under laboratory conditions and holds strong potential for future development and validation in hospitals and other contaminated public spaces. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=91 SRC="FIGDIR/small/715580v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@150cefcorg.highwire.dtl.DTLVardef@450831org.highwire.dtl.DTLVardef@1cfd6borg.highwire.dtl.DTLVardef@1419ba8_HPS_FORMAT_FIGEXP M_FIG C_FIG IMPORTANCEMicroorganisms that form biofilms on surfaces are difficult to eliminate and contribute to the spread of infections in healthcare and indoor environments. There is a need for practical, easy-to-use disinfection technologies that can effectively reduce such contamination. In this study, we developed a compact, in-house, wireless UV-C disinfection system designed for flexible operation across different surface types. The system was evaluated under controlled laboratory conditions using representative biofilm-forming bacterial and fungal pathogens. Our findings show that the system can effectively reduce microbial contamination, demonstrating proof-of-concept efficacy. This work highlights the potential of accessible, non-chemical UV-based technologies and supports their further validation for applications in real-world disinfection settings.

The accumulation of microorganisms and macroorganisms on aquatic surfaces poses economic and ecological challenges, particularly in maritime transport. Traditional antifouling methods, such as biocidal coatings containing toxic compounds like tributyltin (TBT) and copper, are effective but harmful to the environment. This study investigates eco-friendly antifouling alternatives, focusing on nature-inspired compounds (NIAFs) GBA 26 (GBA) and DPC345DHC (DH345), derived from polyphenols and flavonoids, respectively. The ecotoxicity of these compounds was evaluated using standardized assays with various species, including embryos of Danio rerio (zebrafish) (OECD TG 236), the algae Raphidocelis subcapitata (OECD TG 201), and the bacteria Vibrio fischeri (ISO 11348-2), along with nuclear receptor transactivation assays in Mytilus galloprovincialis (Mediterranean mussel). Gallic acid derivative GBA and 24h-transformation products showed low toxicity in zebrafish embryos, while dihydrochalcone DH345 inflicted developmental toxicity in zebrafish at 1 mg/L and above. Comparatively, tralopyril, a commercial biocide, exhibited significant toxicity at lower concentrations. Transcriptomic analysis of zebrafish embryos treated with GBA revealed selective gene modulation related to stress response, ion transport, and protein synthesis. Both, GBA and DH345, were shown to inhibit algae growth at 0.1 mg/L. Vibrio fischeri assay showed no toxic effects for any of the tested compounds. Nuclear receptor transactivation assays conducted with GBA revealed no activation of PPAR or PXR receptors. These findings suggest GBA and DH345 as potential eco-friendly antifouling agents with lower environmental risks than established antifoulants such as tralopyril. However, further research is needed to evaluate their potential long-term ecological impacts, particularly chronic toxicity across various organisms. This study advances the pursuit of sustainable antifouling solutions that prioritize environmental protection.

Bacteria of the genus Achromatium are known for their large cell sizes and intracellular calcium carbonate deposits. Achromatium inhabit freshwater, brackish, and marine sediments where they accumulate to high abundances at the oxic-anoxic interface. These bacteria alter their vertical position in the sediment along with daily fluctuations in oxygen concentrations. Yet, the mechanism behind their migration in the sediment remains unknown. In this study, we used chemotaxis assays and time-lapse microphotography to analyze the motility and chemotactic behavior of Achromatium oxaliferum. Microscopic observations revealed that rolling and gliding were the main forms of locomotion exhibited by Achromatium. In absence of any stimulant, the movement appeared to be mostly random and changes in direction frequently occurred. Chemotaxis assays showed a negative chemotaxis of Achromatium to oxygen, sulfide, and nitrate, as evidenced by the change from undirected to directed locomotion against the respective chemical gradient. For periods of more than 1 hour, Achromatium cells moved continuously towards regions of low concentration. We further investigated whether the genetic repertoire of Achromatium corresponds to our observations. Based on lab experiments and bioinformatic analyses we conclude that Achomatium motility is propelled by type IV pili guided by a plethora of chemo- and photoreceptors. We conclude that Achromatium uses negative chemo- and phototaxis to confine their distribution in aquatic sediments between opposing oxygen and sulfide gradients. This allows Achromatium to dynamically adjust its position in redox gradients, and thus is likely to have a major contribution to its success in the global colonization of diverse aquatic sediments.

The increasing discharge of treated wastewater effluent poses a growing threat to freshwater ecosystems. Although wastewater treatment plants reduce chemical pollution, they do not fully remove many biologically active compounds. Behavioural responses in aquatic organisms provide sensitive and ecologically relevant indicators of sublethal contaminant exposure, offering insight into underlying physiological disruption and potential ecological consequences. Here, we examined the behavioural and neurotoxic effects of a seven-day experimental exposure to treated wastewater effluent in the noble crayfish (Astacus astacus). We quantified four ecologically important behaviours: (1) shelter use, a key antipredator strategy, (2) food seeking, (3) the ability to detect and respond to wastewater-associated olfactory cues, and (4) locomotor activity was assessed across all behavioural contexts. Cholinesterase (ChE) activity was measured as a biomarker of neurotoxicity. Exposure to wastewater effluent significantly altered crayfish behaviour. Exposed individuals exhibited higher locomotor activity compared to controls, exposed crayfish avoided areas containing wastewater cues, spending less time near the effluent source. Similarly, ChE activity was significantly reduced in exposed crayfish, indicating neurotoxic effects. The concurrence of ChE inhibition and behavioural modification suggests that effluent-derived contaminants may interfere with neural signalling pathways underlying crayfish locomotion and habitat selection. Overall, our results demonstrate that short-term exposure to treated wastewater effluent can induce both neurochemical disruption and ecologically relevant behavioural changes in A. astacus. Such alterations may increase vulnerability to predation and influence population dynamics in effluent-receiving waters, highlighting the importance of integrating behavioural endpoints with mechanistic biomarkers in assessing sublethal impacts of wastewater contamination.

Background Ambient air pollution is a leading global health risk and disproportionately affects populations of Low- and Middle-Income Countries (LMICs). In 2021, WHO revised its Air Quality Guidelines (AQG), lowering recommended annual limits for Particulate Matter 2.5 (PM2.5) and Nitrogen Dioxide (NO2). We estimated the potential health and economic impacts of achieving WHO Interim Target 3 (IT3) and AQG concentrations across LMICs. Methods We conducted a health impact assessment across 136 LMICs to quantify one-year changes in all-cause and cause-specific mortality (chronic obstructive pulmonary disease [COPD], ischaemic heart disease [IHD], and stroke) and disease incidence (COPD, dementia, IHD, and stroke) under WHO IT3 and AQG counterfactual scenarios for PM2.5 and NO2. Concentration-response functions were applied at 1km x 1km resolution. Economic welfare impacts of mortality risk reductions were estimated using country-adjusted values of a statistical life (VSL, Int$ PPP-adjusted 2021). Direct medical and productivity-related costs associated with incident cases were estimated using a cost-of-illness (COI) framework. Uncertainty intervals (UI) reflect uncertainty in concentration-response functions. Results Attainment of WHO IT3 and AQG concentrations for PM2.5 was associated with an estimated 16.04% reduction (6.58million, UI: 6.10-7.07million) and 22.97% reduction (9.43million, UI: 8.75-10.11million) in annual deaths, respectively. Corresponding VSL-based estimates of deaths averted were Int$5.5 trillion (7.0% of aggregate LMIC GDP) and Int$8.4 trillion (10.6% of GDP), respectively. For NO2, IT3 and AQG scenarios were associated with estimated reductions of approximately 1.06% (approximately 435,000 deaths, UI: 388,000-483,000) and 2.79% (435,000 deaths; UI: 388,000-483,000), yielding gains of Int$0.6 trillion (0.7% of GDP) and Int$1.5 trillion (1.9% of GDP). Disease-specific mortality reductions were most prominent for IHD and stroke in Asia and Africa. Under the PM2.5 AQG scenario, an estimated 2.82million (1.67-2.97) COPD, 1.10million (0.83-1.37) dementia, 7.3million (6.41-8.19) IHD, and 2.3million (2.19-2.41) stroke cases could be delayed or averted in one year. Associated reductions in direct medical and productivity-related costs were greatest for IHD, COPD, and stroke. NO2-related morbidity reductions were smaller across all outcomes. All estimates represent one-year changes in risk relative to counterfactual exposure and may reflect delayed rather than permanently avoided events. Discussion Achieving both WHO IT3 and AQG values in LMICs could yield substantial reductions in premature mortality and disease incidence, particularly for cardiovascular and respiratory conditions, alongside large, monetised welfare gains from reduced mortality risk. These findings underscore the considerable societal value of air quality improvements and support accelerated action toward meeting WHO guideline levels in regions bearing the highest pollution burden.

Military aviation training noise remains understudied despite its widespread impacts across urban, rural, and wilderness areas. The predominance of low-frequency noise and repetitive training can create pervasive noise pollution, yet past research often fails to capture the full range of health and quality-of-life effects. This study analyzed two complaint datasets related to Whidbey Island Naval Air Station noise: U.S. Navy records (2017-2020) and Quiet Skies Over San Juan County data (2021-2023). We analyzed and mapped sentiment intensity from noise complaints relative to modeled annual noise exposure, developed a typology to classify impacts, and modeled the environmental and operational factors influencing complaints. Findings revealed widespread negative sentiment and anger, often beyond the bounds of estimated noise contours, suggesting that annual cumulative noise models inadequately estimate community impacts. Complaints consistently highlighted sleep disturbance, hearing and health concerns, and compromised home environments due to shaking, vibration, and disruption of daily life. Residents also reported significant social, recreational, and work disruptions, along with feelings of fear, helplessness, and concern for children's well-being. The number of complaints were strongly associated with training schedules, with late-night sessions being the strongest predictor. A delayed response pattern suggests residents reach a frustration threshold before filing complaints. Overall, our findings demonstrate persistent negative sentiment and diverse impacts from military aviation noise. Results highlight the need for improved noise metrics, modeling and operational adjustments to mitigate the most disruptive effects.

Antimicrobial resistance (AMR) is a significant and growing threat to human, plant and animal health, the global economy, and food security. The One Health approach to AMR recognises the role of the environment in the evolution, emergence, and dissemination of AMR. In part, this is due to anthropogenic pollution that releases AMR organisms alongside cocktails of compounds that may select for AMR in situ, which then pose an exposure risk to humans and animals. This has spurred growing interest from cross-sectoral stakeholders in environmental risk assessment (ERA) of antibiotics, with regards to their selective potential. Many different experimental and modelling approaches have been used to determine the lowest concentration of an antibiotic that may select for AMR. Debates continue regarding which individual approach, if any, may be best for determining concentrations of antibiotics that may select for AMR, for ERA purposes. This paper contributes to this ongoing discourse by refining and using a previously published method SELECT (SELection Endpoints in Communities of bacTeria) to rapidly generate predicted no effect concentrations for resistance (PNECRs) for 32 antibiotics on the premise that reduction in growth of complex community of bacteria correlates with selection for AMR resistance genes. The database of PNECRs of antibiotics presented here is the largest generated using a single experimental, empirical approach that will aid future efforts towards creating a standardised test. PNECR data were used to conduct ERAs using measured environmental concentrations of antibiotics to rank antibiotics by potential selection risk in different environments. The experimental approach and statistical code have been made open access, with online tutorials available to facilitate other laboratories using the SELECT 2.0 method. Finally, we discuss the limitations of this approach and how these could be addressed in future studies.

Industrial waste containing hydrophobic pollutants, like oils and hydrocarbons, is toxic and difficult to degrade, posing both ecological and human health risks. Biosurfactants are eco-friendly surface-active compounds produced by microorganisms, known for their ability to lower surface and interfacial tension, enhancing the solubility and bioavailability of hydrophobic compounds, facilitating their breakdown. The current study focuses on isolating biosurfactant-producing bacteria from industrial waste sources near Dhaka, Bangladesh, and characterizing their properties, determining potential usage. Using diesel-enriched nutrient agar, bacterial strains were isolated and screened for biosurfactant production by oil displacement, emulsification index (E24%), and drop collapse assay. The most promising isolates were characterized according to their biochemical activities and 16S rRNA amplicon-based sequencing. Isolation and characterization of the surfactants have been carried out using chromatographic techniques. The identified bacteria passed the drop collapse and oil displacement tests. CTAB agar assay, indicates their anionic nature, showing an emulsification index ranging 10-41%. The potential biosurfactant producers belong to Bacillus, Pseudomonas, Acinetobacter, and Enterobacterium genera. The surfactants showed antibacterial, antifungal, and plant growth promotion activity and have been characterized in terms of pH stability, salinity, adhesion, and temperature tolerance. The study successfully identified and characterized potential biosurfactant-producing bacteria from industrial waste, highlighting their efficiency in breaking down hydrophobic pollutants and hydrocarbons. These microorganisms provide a green and economical substitute for synthetic surfactants due to their biodegradability and lower toxicity. Upon further research and scaling, these bacteria can be a good source of biosurfactants for potential applications in industrial, agricultural, and biomedical fields. IMPORTANCEThe study carries high significance as it creates multi-disciplinary scopes for utilizing these environmentally adapted biosurfactant-producing bacteria in industry, agriculture, and medicine. Since the bacterial isolates have hydrocarbon degradation ability, upon optimization for higher production, industrial usage in oil refinery and other industries can be adopted. Due to their biodegradable nature, usage in wound healing bandages and as antimicrobial agents in medicine will be noteworthy. The isolates have plant growth promotion ability and utilizing them as biofertilizer will reduce the dependency on chemical fertilizers. This is the first detailed report on biosurfactant-producing bacteria from this industrial waste-polluted Turag River of Dhaka City. Moreover, it compiles detailed screening protocols and methods for analyzing such environmentally friendly microbes. Such characterization also opens the scope for optimizing the production of the surfactant compounds on a large scale and utilizing them commercially.

Air pollution has been increasingly linked to adverse neurodevelopmental and neurodegenerative outcomes. While experimental and preclinical studies suggest that exposure to particulate matter (PM), particularly during gestation, may disrupt cognitive development, the impact of short-term PM exposure on cognitive and behavioral functioning in healthy young populations remains insufficiently explored in Spain. Moreover, few studies have incorporated individualized dosimetry models to estimate exposure more accurately. This study included 186 healthy young adults (mean age = 20.4 years) recruited from three Spanish cities (Teruel, Almeria, and Talavera) characterized by different pollution levels. Ambient fine and coarse PM concentrations were recorded 8, 15, and 30 days prior to psychological assessment. Instead of relying solely on raw in situ environmental measurements, individualized PM deposition was estimated using the Multiple-Path Particle Dosimetry Model (MPPD), allowing a more biologically meaningful exposure approximation. Psychological outcomes were assessed using validated questionnaires: DASS-21 (depression, anxiety, stress), BIS-11 (impulsivity), UCLA Loneliness Scale, and SWLS (life satisfaction). Behavioral performance was evaluated using computerized versions of the Attentional Network Task (ANT) and the Stroop Task. Blood NRF2 concentrations were analyzed as a biomarker potentially related to oxidative stress mechanisms. In situ data indicated that Talavera presented the highest pollution levels, followed by Almeria and Teruel. Linear regression analyses showed that coarse PM exposure across 8-, 15-, and 30-day windows significantly predicted poorer Executive Control Index performance in the ANT. Additionally, 15-day coarse PM and 30-day fine PM exposure were associated with greater cognitive interference. Oxidative stress markers were significantly associated with PM exposure levels. These findings support emerging evidence that short-term PM exposure may negatively affect executive and attentional processes even in healthy young adults. Further longitudinal research incorporating individualized exposure modeling is warranted to clarify causal pathways and underlying biological mechanisms. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=97 SRC="FIGDIR/small/713644v1_ufig1.gif" ALT="Figure 1"> View larger version (79K): org.highwire.dtl.DTLVardef@1a0ac13org.highwire.dtl.DTLVardef@1812accorg.highwire.dtl.DTLVardef@120bf07org.highwire.dtl.DTLVardef@dd9a7c_HPS_FORMAT_FIGEXP M_FIG C_FIG

BackgroundRising global temperatures and eutrophication are increasing the intensity and frequency of cyanobacterial harmful algal blooms that release toxins including microcystin-LR (MC-LR). MC-LR inhibits protein phosphatases in the human liver and brain, but its accumulation in the placenta is unclear. Placental transporter expression varies across pregnancy and is influenced by physiological cues, such as low oxygen concentrations which activate HIF1A, and trophoblast cell fusion forming syncytiotrophoblasts that engage CREB-driven transcription. This study examined whether MC-LR accumulates in placental cells, which transporters mediate uptake, and how these transporters are regulated by HIF1A and CREB. MethodsIntracellular accumulation of MC-LR (0.1-10 {micro}M, 3 hour) was measured in human cytotrophoblasts (JAR, BeWo) and extravillous trophoblasts (HTR-8/SVneo) by western blotting for MC-LR-adducted proteins. Organic anion transporting polypeptide (OATP) involvement was tested using cyclosporin A (10 {micro}M), an OATP inhibitor, before exposure to the OATP substrate or MC-LR. Cells were also cultured under 3%, 8%, or 20% O2 to induce hypoxic responses or treated with forskolin (a potent intracellular cAMP inducer) to stimulate cell fusion before MC-LR exposure. ResultsMC-LR accumulated in all three placenta cell lines in a concentration-dependent manner. Cyclosporin A reduced MC-LR uptake by 57% in JAR cells, confirming OATP-mediated transport. Low O2 increased OATP4A1 expression and function but reduced protein phosphatase expression, decreasing MC-LR-bound proteins by 52-72%. Forskolin increased OATP4A1 expression and enhanced MC-LR uptake >2.5-fold. ConclusionMC-LR enters placental trophoblasts via active OATP transport, likely OATP4A1, and uptake increases under hypoxia and trophoblast fusion.

ObjectiveTo investigate associations between long-term environmental exposures, both external (ambient air pollution and built environment) and internal (circulating anthropogenic chemicals), and the human plasma metabolome, with the aim of generating biologically plausible hypotheses about affected metabolic pathways. MethodsWe analyzed plasma from 989 Estonian Biobank participants using untargeted LC-HRMS (Metabolon HD4). External exposures (PM2.5, PM10, NO2, ozone and built-environment metrics) were assigned using spatiotemporally resolved models developed in the EXPANSE project. Internal exposures were defined as ubiquitous anthropogenic compounds detected in the same metabolomics dataset. Associations between exposures and individual metabolites were quantified using left-censored regression models and then mapped to metabolite classes (Metabolon) and KEGG pathways. For enrichment analyses, one-sided Kolmogorov-Smirnov tests were applied to external exposures and Fishers exact tests to internal exposures. False discovery rate was controlled at 1% per exposure and database. ResultsExternal air pollutants exhibited distinct metabolic patterns: Higher NO2 exposure was associated with enrichment of metabolites involved in tyrosine metabolism; higher ozone with monohydroxy and dicarboxylate fatty acids (consistent with lipid peroxidation); and higher PM2.5 with acyl-carnitine subclasses and carbohydrate metabolism (glycolysis / gluconeogenesis / pyruvate). Built-environment associations were heterogeneous across metabolites and pathways. Internal anthropogenic chemicals showed broader metabolic associations than external exposures, involving a larger number of metabolites and metabolic classes. PFAS (PFOA, PFOS) were associated with long-chain polyunsaturated fatty acids (n3/n6) and lysophospho-lipids. Associations with 4-hydroxychlorothalonil, a fungicide, pointed to androgenic steroid metabolites and alpha-linolenic acid metabolism. The phenolic 2,4-di-tert-butylphenol, a plastic associated chemical, showed widespread associations with lipid classes, suggesting disruption of membrane remodeling and fatty acid handling. ConclusionLong-term environmental exposures, both external and internal, are measurably reflected in the human plasma metabolome. Across exposure domains, recurrent signals involved lipid metabolism, membrane composition, and oxidative stress-related pathways, highlighting these as common biological targets of environmental exposures. The findings generate testable hypotheses, including nitrosative stress-related alterations for NO2, lipid peroxidation for ozone, energy-metabolism perturbations for PM2.5, potential endocrine activity for chlorothalonil metabolites, and possible obesogenic effects of 2,4-di-tert-butylphenol.

Space-based platforms currently represent the most accurate means to experimentally assess the influence of the space environment on biological systems. However, performing such experiments remains technically challenging and requires highly specialized instrumentation. This study describes the current development and hardware qualification of ExocubeBio, a miniaturized experimental platform for in-situ biological space exposure. This experiment is scheduled for installation on the exterior of the International Space Station in 2027, as part of Exobio, the European Space Agencys new generation exobiology exposure facility. ExocubeBio will expose live microbial samples to the low Earth orbit environment, and combine autonomous in-situ optical density and fluorescence measurements, with the capacity to return preserved samples to Earth. Achieving these experimental goals requires a specialized, robust and reliable hardware system. The ExocubeBio hardware testing described here includes assessment of material biocompatibility and durability, functional validation of the miniaturized fluidic system, and optimization of the integrated optical subsystem for optical density and fluorescence measurements. These results demonstrate that the ExocubeBio experimental hardware components can each execute their core functional and operational requirements; subsystems allow for sample exposure, in-situ measurements of microbial cultures, and the chemical preservation of samples for post-flight analysis. As ExocubeBio transitions from hardware development to mission readiness, the results presented here validate the overall design and engineering approaches utilized. By combining the strengths of in-situ monitoring and sample return, ExocubeBio represents a significant advancement in space-based experimentation, and will provide new insights into microbial responses to the space environment.

The microbiota and microbiome associated with zooplankton remains rather understudied compared to other animal groups and/or taxa. The present study aimed at investigating the whole-body bacterial microbiota of Daphnia spp. in two contrasting Greek lakes, the shallow and hypertrophic Lake Koronia vs. the deep and mesotrophic Lake Vegoritida, including both egg-bearing and non-egg-bearing individuals. In both lakes, 2,060 bacterial operational taxonomic units (OTUs) were found, with 223 of them being conditionally rare (crOTUs) with low contribution even for the dominant phyla, with L. Vegoritida having more crOTUs than L. Koronia. The individuals microbiota had inconsiderable overlap with the surrounding water microbiota in both lakes. The two lakes showed significant differences in their Daphnia -associated microbiota. L. Koronia had richer OTUs and rather homogeneous bacterial communities, with higher occupancy. Overall, no significant differences in between the microbiota of egg-bearing and non-egg-bearing Daphnia individuals in both lakes. However, regarding the most important OTUs (miOTUs), the L. Koronia miOTUs were highly overlapped between the individuals with and without eggs, with only one missing from the individuals without eggs. In L. Vegoritida the individuals without eggs had only six miOTUs and while egg-bearing individuals had nine different ones; the two lakes had no shared miOTUs., considerable differences occurred.. A total of 27 miOTUs, was found and belonged to the Pseudomonadota, unclassified Bacteria, Cyanobacteria, Bacteroidota, Bacillota and Actinomycetota. Those miOTUs, where assignment to the genus level was possible, they were related to Cyanobium, Mucilaginibacter, Flavobacterium and Staphylococcus. This study showed that lake morphotype and ecological status can exert some impact on Daphnia-associated bacterial microbiota, with more pronounced effects on egg-bearing and non-egg-bearing individuals.

Benzalkonium chloride (BAC) is widely used as a disinfectant in cleaning products and is frequently detected in indoor dust. In this study, we assessed dust samples, along with information on cleaning product use, from 24 pregnant participants. Dust samples were analyzed for BAC concentration and microbial tolerance. Different chain lengths of BAC (C12, C14, and C16) were quantified using LC-MS/MS, and bacterial isolates were tested for BAC tolerance using minimum inhibitory concentration (MIC) assays. BAC was ubiquitously detected, with C12 and C14 being dominant. Higher BAC concentrations were associated with reported disinfectant use and increased microbial tolerance. These findings suggest that indoor antimicrobial use may promote microbial resistance, highlighting potential exposure risks in indoor environments and the need for further investigation into health and ecological impacts.

Ethylene oxide (EtO) is primarily used as an intermediate in the manufacture of chemicals, with a minor use as a sterilant for medical equipment and food products. It is a direct-acting alkylating agent that reacts with cellular macromolecules, including proteins and DNA. EtO has been shown to induce tumors in rodents and humans. DNA reactivity has been the postulated mode of action (MOA) for its carcinogenicity. The current study has investigated the dose response for EtO-induced genetic damage to inform the biological plausibility of a dose-response model for cancer risk assessment. Male and female B6C3F1 mice were exposed to 0, 0.05, 0.1, 0.5, 1, 50, 100, or 200 ppm EtO by whole-body inhalation (6 hours/day for 28 days, 7 days/week). Mutagenicity was assessed by determining the frequency of mutant Pig-a phenotype in reticulocytes (RET) and mature red blood cells (RBC) on Day 28. Cytogenetic damage was evaluated by the erythrocyte micronucleus (MN) test in blood samples collected on Days 5 and 28. EtO is a relatively weak genotoxicant with treatment-related increases in Pig-a and MN frequencies being seen primarily at 200 ppm. The hockey-stick shaped dose response for genetic damage may be conservatively interpreted as being no more than a linear response with a single slope. Thus, a cancer risk assessment dose-response model consisting of a single linear slope throughout the exposure range is biologically plausible and consistent if EtO were acting through a mutagenic MoA for its carcinogenicity.