Search Results (967)

Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant widely detected in aquatic ecosystems, but its subcellular targets and the mechanisms by which it disrupts light resource utilization in photosynthetic protozoa remain poorly understood at concentrations spanning environmentally typical to supra-environmental levels. Here, Euglena gracilis G.A. Klebs was exposed to PFOS at concentrations spanning environmentally typical (0.5 µg/L), hotspot-relevant (5 µg/L), and supra-environmental (50 µg/L) levels. Subcellular distribution, phototaxis, photosynthetic light reactions, and energy metabolism were investigated using isolated chloroplast assays, transcriptomics, and proteomics. TEM-EDS mapping revealed pronounced fluorine signal enrichment, attributable to PFOS, in the eyespot and chloroplasts. Eyespot fluorine enrichment was associated with impaired phototactic motility and an altered light perception threshold. PFOS did not acutely inhibit the maximum photochemical efficiency of photosystem II (Fv/Fm); instead, a transient upregulation of photosynthesis-related genes was observed, which weakened with prolonged exposure, whereas the photosynthetic electron transport rate (ETR) was significantly reduced. PFOS significantly reduced ATP levels and ETR, while Fv/Fm remained unchanged and non-photochemical quenching (NPQ) was elevated. Isolated chloroplast assays revealed that PFOS inhibits Mg²⁺-dependent ATP hydrolytic activity in the chloroplast-enriched fraction and impairs thylakoid electron transport, consistent with impaired chloroplast ATP synthase function, though the specific molecular target and mechanism remain to be conclusively demonstrated. Transcriptomic and proteomic analyses revealed compensatory upregulation of photosynthesis pathways but suppression of ATP synthesis and redox homeostasis. Collectively, our results suggest that PFOS impairs chloroplast ATP synthase function, accompanied by reduced ETR and elevated NPQ. Together with the eyespot-associated phototaxis impairment, these effects suggest that PFOS may dually disrupt light acquisition (behavioral) and light conversion (physiological) in E. gracilis. This dual impairment may compromise the ecological fitness of Euglena in PFOS-contaminated environments, especially under prolonged exposure. It should be noted that the subcellular fluorine mapping is qualitative, the phototaxis assay reflects population-level responses, and the ATP synthase impairment interpretation is indirect; the proposed mechanistic model remains a hypothesis requiring further direct experimental validation. Full article

African soils face increasing levels of metal pollution due to industrialization, artisanal mining activities, improper waste management, and enhanced agricultural productivity. However, unlike many organic pollutants, heavy metals do not degrade naturally and therefore persist in environmental systems for prolonged periods. Heavy metals accumulate over many decades in the soil and bioaccumulate through the food chain causing severe health complications such as cancer, kidney problems, and neurological impairment. This paper reviews the current literature on the origin, prevalence, and behavior of the main pollutants Pb, Cd, Cr, As, Hg, and Cu. The major phytoremediation methods including phytoextraction, rhizofiltration, phytostabilization, and phytovolatilization are highlighted alongside in planta screening methods for hyperaccumulating plants including Berkheya coddii (Ni) and Haumaniastrum robertii (Co). The paper evaluates various enhancement techniques such as the use of chelators, Rhizobium inoculations, and genetic modifications. The significance of these approaches in tropical and subtropical climates is discussed. The paper suggests a holistic framework involving empirical kinetic modeling, geospatial machine learning (random forest, kriging), and molecular omics in prediction modeling. Major hurdles in such predictions include lack of field-based verification of the models, biotechnology safety of genetically modified (GM) organisms, and inadequate regulations. Future perspectives emphasize community-driven phytomining, biomass recycling, and resilient phytoremediation solutions. Full article

Introduction: The discharge of treated wastewater into coastal and marine environments represents a continuous source of pollutants, including pharmaceuticals and plastic additives with endocrine-disrupting (ED) potential. These compounds are of increasing concern for the European Union due to their capacity to interfere with hormonal systems and their inclusion in current environmental monitoring priorities. ED compounds may induce sublethal effects in aquatic organisms, particularly in vertebrates, where endocrine pathways are highly conserved. In this context, the use of Cyprinodon variegatus, a euryhaline fish species, provides a suitable model to assess potential risks in marine ecosystems. Despite advances in wastewater treatment technologies, the persistence of biologically active substances in treated effluents remains a concern. Objective: This study aims to evaluate whether treated effluent water still contains compounds with endocrine-disrupting activity and to assess their potential effects on marine organisms. Methodology: Larvae of C. variegatus from a laboratory stock maintained at ECIMAT (University of Vigo), one of the few available stocks of this species in Europe, were exposed for 48 h to environmentally relevant dilutions (1:10, 1:30, and 1:100) of wastewater treatment plant effluent collected after UV disinfection as the final treatment step. Pools of 10 larvae were used for each condition. Sublethal effects were assessed through gene expression analysis using quantitative PCR (qPCR), targeting biomarkers involved in endocrine regulation. Two housekeeping genes (tbp and hprt) were used for normalization. Estrogenic responses were evaluated through vtgab and zp2, while androgenic responses were assessed using 17hsd and 11hsd. Results: Preliminary results indicate significant alterations in estrogen-related gene expression, particularly in vitellogenin (vtgab) and zona pellucida (zp2), highlighting the activation of estrogenic pathways and supporting the presence of endocrine-disrupting activity in treated effluent water. Conclusions: This study highlights the relevance of assessing endocrine disrupting activity in treated effluents and supports the use of molecular biomarkers as sensitive tools for evaluating their potential impact on marine ecosystems, contributing to the improvement of wastewater monitoring and management strategies. Full article

Polycyclic aromatic hydrocarbons (PAHs) are widespread, persistent pollutants that can be sequestered within human adipose tissue due to their lipophilic nature. While this accumulation poses toxicological risks depending on dose and individual susceptibility, the specific morphological impact of chronic PAH storage on tissue architecture remains poorly defined. Here, we performed a histopathological and morphometric analysis on human subcutaneous adipose tissue samples characterized by high pyrene levels. We evaluated tissue organization, collagen distribution, the presence of inflammatory, neural, and vascular alterations and adipocyte morphometry to assess the structural response to PAH sequestration. Despite high pyrene concentrations, PAH-positive tissues maintained preserved overall architecture with normal collagen distribution, absence of lymphocytic infiltration, low macrophages, unaltered nerve fiber patterns, without evidence of vascular remodeling. Morphometry revealed smaller adipocyte area in PAH-positive samples, although not statistically significant. Our experimental data indicate that high PAH accumulation does not necessarily induce subcutaneous adipose tissue remodeling, suggesting that biochemical or metabolic alterations might occur even in the absence of evident histological changes. Further studies, with a broadened cohort, are needed to define the threshold at which PAHs’ presence translates into permanent tissue damage. Full article

Introduction: Temperature is a key environmental factor influencing the physiological and biochemical processes of aquatic organisms, including xenobiotic metabolism. Understanding how temperature modulates the toxicological effects of pollutants such as polycyclic aromatic hydrocarbons (PAHs) is crucial in the context of climate change. Among these compounds, benzo[a]pyrene (BaP) and benzo[a]anthracene (BaA) are priority pollutants in aquatic environments, resulting from incomplete combustion. Their relevance is attributed to persistence and metabolic bioactivation potential. Fish primary hepatocyte cultures represent a relevant in vitro model for studying combined effects of thermal stress and chemical exposures, while supporting the 3Rs principles (Replacement, Reduction, and Refinement). Objective: This study aims to assess temperature-dependent effects of BaP and BaA, and their mixtures in brown trout hepatocytes using cytochrome P450 1A (CYP1A) immunohistochemistry as an indicator of xenobiotic metabolism. Methodology: Primary hepatocytes were isolated using a two-step collagenase perfusion method and cultured in 24-well plates at 18 °C and 22 °C. Cells were exposed for 72 h to supplemented L-15 medium (control) or to 0.1% dimethyl sulfoxide in supplemented L-15 medium (solvent control), as well as to single exposures of 1 and 10 µM of BaP and BaA and to equimolar mixtures of both compounds (1 and 10 µM). Viability was assessed using the lactate dehydrogenase (LDH) assay. CYP1A immunostaining was quantified based on cytoplasmic staining intensity relative to background area. Results: No significant effects on cell viability were observed under any condition. Temperature significantly reduced CYP1A expression in single exposures at 22 °C compared to 18 °C. BaP induced a significant dose-dependent increase, while BaA differed from controls only at 10 µM. In mixtures, only treatment- and dose-dependent effects were observed, with no temperature influence detected. Conclusions: Overall, the data highlight temperature as a key modulator of biochemical responses to PAHs, with single and mixed exposures eliciting distinct effects and suggesting potential synergism in mixtures. Full article

Introduction: Aquatic ecosystems are major reservoirs for both legacy and emerging contaminants, facilitating their distribution throughout the environment and bioaccumulation across different trophic levels. As such, wildlife acts as a valuable tool for biomonitoring these contaminants and serves as a key indicator of environmental pollution within the One Health framework. Despite this, knowledge regarding the application of this framework alongside the assessment of aquatic contaminants using wildlife species remains fragmented. Objective: This study aims to synthesize current evidence on aquatic contaminants using wildlife as sentinels of environmental pollution and to explore how the One Health concept is applied in this field. Methodology: A systematic database search was conducted in SCOPUS, and the retrieved studies were screened according to predefined inclusion and exclusion criteria, as well as their relevance to the One Health concept. Results: Despite its timely relevance, only fourteen studies have adopted the One Health approach to assess contaminants in aquatic species. The selected studies focused mainly on plastic particles (53.33%), such as macro- and microplastics; heavy metals (26.67%), such as mercury (Hg), cadmium (Cd), Nickel (Ni), lead (Pb), and selenium (Se); persistent organic pollutants (13.33%), such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), per- and polyfluoroalkyl substances (PFAS), and dioxin/furans; and metalloid (6.67%) arsenic (As). These contaminants were evaluated across four different taxonomic groups: fishes (61.54%), waterbirds (23.08%), mollusks (7.69%) and crustaceans (7.69%). Most studies were conducted in Portugal (37.5%) and the United States of America (18.75%), whereas other countries, including Canada, Australia, Ecuador, Mexico, Indonesia, and Turkey, were mentioned in only one study each (6.25%). Conclusions: Monitoring levels of contaminants in wildlife is essential not only to understand the dynamics of environmental pollution, but also to preserve the integrity of ecosystems while safeguarding animal and human health. However, the limited number of studies adopting a One Health perspective results in an incomplete representation of contaminant classes and affected taxa. These findings highlight the urgent need to expand wildlife-based monitoring strategies within a One Health framework, aiming to improve environmental risk assessment and deepen our understanding of the impacts of pollution across ecosystems, animals and humans. Full article

Eutrophication remains a persistent water-quality problem in shallow lakes, where external inputs interact with internal loading and biogeochemical cycling. Although floating treatment wetlands (FTWs) are increasingly promoted as nature-based solutions for water remediation, their field-scale interpretation in hydrologically complex eutrophic lakes remains challenging. This study examined the spatial organization of water quality during the operation of a floating-island system in a eutrophic urban lake affected by polluted tributary inflow. The study was not designed to quantify isolated FTW removal efficiency, but to evaluate spatial water quality organization during FTW operation under real-use field conditions. Water quality was monitored over two growing seasons across six functionally defined zones, and spatial and temporal patterns were analyzed using descriptive statistics and linear mixed-effects models. The results showed parameter-specific spatial structuring rather than a uniform treatment response. The clearest inlet-lake contrasts were observed for electrical conductivity (EC), suspended matter (SM), and nitrate nitrogen (NO₃-N), whereas biochemical oxygen demand (BOD₅), ammonium nitrogen (NH₄-N), and total organic carbon (TOC) showed lower values at the inlet and higher values in downstream zones. Dissolved oxygen (DO), oxygen saturation (SO), chemical oxygen demand (COD), nitrite nitrogen (NO_2-N), and orthophosphate phosphorus (PO₄-P) showed moderate or non-robust zonal effects. These findings indicate that FTWs in shallow eutrophic lakes should be evaluated through functional zoning and parameter-specific interpretation rather than as isolated units with uniform removal responses. Full article

Particulate emerging contaminants (PECs) pose increasing ecological risks due to their widespread occurrence and complex environmental behaviors, yet their heterogeneous toxic mechanisms remain poorly understood, especially under environmentally relevant conditions and concentration gradients. Here, Chlorella vulgaris was used as a model organism to systematically compare the effects of polystyrene nanoparticles (PSNPs), silver nanoparticles (AgNPs), and titanium dioxide nanoparticles (TiO₂NPs) across environmentally relevant and elevated concentrations (100 μg/L and 10 mg/L). Distinct toxicity pathways were identified among PEC types. PSNPs primarily induced chronic interference via particle–cell interactions, heteroaggregation, sedimentation-driven shading, and extracellular polymeric substance (EPS) regulation, rather than ROS-dominated toxicity. In contrast, AgNPs exhibited transformation-driven toxicity, undergoing intracellular speciation into Ag₂S, AgCl, and Ag⁺, which triggered oxidative stress, membrane damage, and lipid peroxidation. TiO₂NPs showed relatively high bioavailability and persistent oxidative stress effects. These results demonstrate that PEC toxicity evolves with particle type and concentration. Importantly, oxidative stress alone is insufficient to capture PEC ecotoxicity, which also involves the long-term impacts on algal behavior, sedimentation dynamics, and energy metabolism. This study provides mechanistic insights into PEC-induced algal toxicity and supports the source-oriented management of particulate pollutants in aquatic environments, particularly in hotspot scenarios such as wastewater discharge and sediment resuspension. Full article

The sustainability, crop production, and food safety of agriculture are increasingly challenged by microplastic pollution, as agricultural soils are the largest reservoirs and may serve as points of contact for plastic particles in the food chain. This review provides a comprehensive overview of plant materials, fate and uptake pathways, detection techniques, and the possible risks of microplastics in agriculture. Agroecosystems are also a source of microplastics, such as plastic mulch films, sewage sludge, compost and manure additives, wastewater irrigation, polymer-coated fertilizers, greenhouse materials, atmospheric deposition, and decomposition of discarded agricultural plastics. Their distribution and mobility in soil are controlled by polymer composition, particle size, morphology, density, surface ageing, soil texture, organic matter content, tillage practices, runoff, leaching, and soil biota. Recent data show that microplastics, especially smaller microplastics and nanoplastics, can attach to root surfaces, penetrate plants via cracks in roots, areas of lateral root development, and apoplastic pathways, and eventually move to tissues aboveground. Plant tissue detection is often accomplished by digestion of the sample, density separation, visual and fluorescence microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, pyrolysis–gas chromatography mass spectrometry, and electron microscopy, but standardization of these methods remains a significant challenge. Microplastics can disrupt seed germination, root structure, nutrient absorption, photosynthesis, oxidative homeostasis, biomass buildup, yield development, and quality. Further, their capacity to transport additives, plasticizers, heavy metals, and persistent organic pollutants raises concerns about the transfer of contaminants to edible plant parts and their potential transfer to human diets. Further studies are needed focusing on field-realistic exposure conditions, long-term crop–soil interactions, nanoplastics behaviour, standardised analysis procedures, uptake and translocation pathways, edible crop risk assessments, and sustainable mitigation approaches to reduce microplastics in agroecosystems. Full article

Climate change is intensifying the release and dispersion of various hazardous chemicals into marine ecosystems, such as algal biotoxins, heavy metals, persistent organic pollutants, and agricultural and industrial wastes. Eutrophication and global warming are responsible for the increase in known and emerging marine biotoxins, such as brevetoxins, palytoxins, pinnatoxins, and cyclic imines. Furthermore, tetrodotoxins and ciguatoxins, which are primarily found in tropical regions, have recently been identified in fish and bivalve molluscs from temperate areas where they had never been previously reported. These toxicants can accumulate in seafood and enter the human food chain, posing a public health concern. This review describes the interrelationship between climate change and its impact on marine organisms and human health, as well as the environment. It recommends integrating a broad range of scientific knowledge, reviewing regulatory policies, and proactively managing public health to counter these environmental threats. Full article

Imidacloprid (IMI), the commonly used neonicotinoid pesticide, has emerged as a persistent aquatic contaminant due to its high solubility and stability, posing risks to non-target organisms and ecosystem health. In this study, a MnZnFe₂O₄/SrWO₄ ferrite–tungstate nanocomposite was synthesized via a hydrothermal process and its ability to photocatalytically degrade IMI under UV light was assessed. SEM, XRD and FT-IR were used to characterize the composite to confirm its structural and morphological features. Photocatalytic performance was systematically investigated by examining the effects of operational factors, including initial pollutant concentration, catalyst dosage, pH, and irradiation time. The MnZnFe₂O₄/SrWO₄ nanocomposite exhibited significantly enhanced activity, achieving up to 87% degradation of IMI within 30 min at pH 9, outperforming individual components (SrWO₄: 37%; MnZnFe₂O₄: 75%) under identical conditions. The degradation kinetics followed a pseudo-first-order model consistent with the Langmuir–Hinshelwood mechanism. Effective interfacial charge transfer between the ferrite and tungstate phases, which suppresses electron-hole recombination and increases the production of reactive species, is responsible for the enhanced performance. Furthermore, the composite demonstrated good stability and reusability across several cycles, indicating its practical applicability. Overall, the results demonstrate the potential of MnZnFe₂O₄/SrWO₄ nanocomposites as efficient and sustainable photocatalysts for removing imidacloprid and similar organic contaminants from aqueous systems. Full article

The electro-oxidation of persistent organic pollutants such as 2-chlorophenol (2-CPh) using boron-doped diamond (BDD) electrodes offers a promising wastewater treatment route, yet conventional mechanistic models (e.g., CFD) suffer from prohibitive computational costs. This study develops a hybrid physics-informed neural network (PINN) to model the electro-oxidation of 2-CPh in a flow-by reactor coupled with a continuous stirred tank under batch recirculation mode. The PINN integrates a diffusion–convection partial differential equation with a lumped-parameter ordinary differential equation for the tank, embedding physical constraints directly into the loss function. The model was trained on simulated data generated from a previously validated parametric model and optimized using a systematic hyperparameter grid search. The PINN achieved excellent agreement with experimental data, yielding a coefficient of determination (R²) of 0.9927, a mean square error of 0.0009, and a root mean square error of 0.0294—outperforming both the CFD and parametric models in accuracy. Sensitivity analysis revealed that the apparent kinetic constant is the most influential parameter (normalized sensitivity of 14.20). While the CFD model required 42 days and the parametric model 8 s, the PINN achieved a balanced trade-off with a runtime of 7.36 h. We conclude that the PINN provides a highly accurate, computationally feasible surrogate model suitable for integration into digital twins and real-time control frameworks for electrochemical wastewater treatment. Full article

China’s pollutant discharge permit system mandates total-quantity emission control for industrial volatile organic compounds (VOCs), yet the actual utilization of permitted capacity remains poorly studied. This study developed an “emission idle rate” (IR = 1 − actual/permitted emissions) framework and applied it to 130 chemical enterprises across three cities in Jiangsu Province using 2020–2024 panel data. The mean idle rate reached 78.1%, with no significant inter-city differences (H = 0.96, p = 0.619), attributable to both production underutilization and systematic over-estimation of emission ceilings inherent in the design-capacity-based permit methodology. Ward hierarchical clustering revealed three emission behavioral patterns, Persistent Surplus (n = 74, IR = 0.95), Declining Surplus (n = 32, IR = 0.69), and Growing Surplus (n = 19, IR = 0.59), exhibiting distinct idle rate levels and temporal trajectories. Cluster differentiation was significantly associated only with production-side emission characteristics, while enterprise economic variables showed no significant effects. The estimated tradeable emission surplus reached 668.3 t/a, though its realization faces transaction cost barriers including the lack of standardized transfer mechanisms and formal VOC trading infrastructure. A quadrant-based strategy matrix integrating idle rate levels with temporal trends is proposed for differentiated permit management. Full article

Edible insects have emerged as a promising alternative to conventional livestock as the global demand for sustainable protein sources rises. Ensuring the safety of insect-based foods is crucial for consumer acceptance and regulatory approval. This review provides a comprehensive overview of the primary chemical and microbiological contaminants associated with edible insects, including heavy metals, pesticides, veterinary drugs, persistent organic pollutants (POPs), mycotoxins, microbiological hazards, and allergenic risks. Current evidence indicates that, when insects are farmed and processed under controlled conditions and in compliance with existing European Union regulations, contaminant levels are generally low and within the range of those found in traditional animal-derived foods. Most studies report that current risks are primarily linked to substrate quality and storage practices. Allergenic risks, particularly cross-reactivity with crustacean and mite allergens, remain a crucial consideration for individuals with sensitivities. Despite these reassuring findings, knowledge gaps persist regarding insect-specific contaminant limits, the metabolic fate of toxins, and the long-term safety of consuming novel insect-derived products. Continued research, targeted monitoring, and regulatory adaptation will be essential to ensure the safe and sustainable integration of insect-based foods into the human diet. Full article

Microplastics (MPs) are increasingly detected environmental contaminants in both marine and freshwater ecosystems, with reported concentrations ranging from a few to thousands of particles per cubic meter depending on location and methodology. Although growing evidence suggests potential risks to aquatic organisms, the extent of their ecological and biological impacts is still under active investigation. Their size, persistence and capacity to transport chemical additives and co-contaminants allow them to enter biological systems by ingestion and respiration. When ingested, MPs cause oxidative stress, inflammation, and metabolic disorders, resulting in the destruction of vital tissues in major body organs including liver, gills, intestines, and brain. They also change gene expression, cause endocrine and immune pathway perturbation, induce apoptosis, and cause gut microbiome dysbiosis, all of which worsen the health and survival of the organism. MPs also serve as vectors of heavy metals, antibiotics, pesticides, and pathogens and enhance toxicity due to the Trojan horse effect and enable bioaccumulation in food webs. Due to their widespread presence in water, soil, air, and food, MP pollution has direct effects on human, animal, and ecosystem health. This review synthesizes current knowledge on the sources of MPs, the mode of exposure, and the mechanism of toxicity and new ecological implications. It also presents mitigation measures, and stresses a One Health paradigm as the key to taking concerted action on the international level to minimize MP pollution and protect both the environment and human health. Full article