Search Results (2,812)

The contamination of microplastics (MPs) and heavy metals (HMs) in water has caused widespread concern, while their effects on submerged macrophytes have rarely been reported. Experiments were carried out to investigate the toxic effects of polyamide microplastics (PAMPs; 0.1%, 0.3%, and 1.0% w/w) and cadmium (Cd; 0.3 and 1.0 mg/L), alone or in combination, on the submerged macrophyte Vallisneria natans (V. natans). The results showed that PAMPs significantly reduced Cd accumulation in leaves (decrease of 2.38% ~ 26.12%) but elevated Cd accumulation in roots. Both Cd exposure and high PAMP exposure alone inhibited plant growth. The combined stress showed concentration-dependent effects: the low Cd concentration (0.3 mg/L) and PAMPs synergistically exacerbated toxicity (synergism, MDR > 1.3), as PAMPs disrupted the sediment structure and enhanced the bioavailability of Cd, whereas when V. natans was co-exposed to the high Cd concentration (1.0 mg/L) and PAMPs, the PAMPs blunted the toxicity of Cd by efficiently adsorbing it (antagonism, MDR < 0.7). Both individual and combined exposures decreased chlorophyll a and chlorophyll b synthesis and increased superoxide dismutase (SOD) and peroxidase (POD) activities as well as malondialdehyde (MDA) content in plant tissues. However, exposure to low and medium concentrations of MPs (0.1% and 0.3%w/w) alone had positive effects on plant growth and photosynthesis systems, while combined exposures exacerbated the damaging effects of PAMPs on the antioxidant defense system in V. natans. These results allow for a better understanding of the synergistic effect of co-contamination of microplastics and heavy metals in freshwater ecosystems, and highlight the necessity of ecological risk assessment during phytoremediation using submerged macrophytes. Full article

The occupational health implications of solar photovoltaic (PV) recycling remain critically under-investigated. This study assessed occupational exposure across the PV recycling value chain in Taiwan, evaluating primary mechanical dismantling and downstream reuse sectors (glass milling and controlled low-strength material [CLSM] batching). Area and personal samples were analyzed for total dust, respirable dust, and trace heavy metals. Results indicated that primary mechanical crushing yielded relatively low ambient dust and negligible toxic heavy metal (e.g., Pb, Cd) aerosols, attributed to the macroscopic ductility of metallic ribbons and EVA shock-absorbing properties. Conversely, a critical “hazard transfer” phenomenon was empirically identified downstream, where intensive secondary grinding and aggregate blending in the downstream reuse sector (glass milling and CLSM batching) systematically shifted the aerodynamic particle size distribution, causing the respirable dust fraction to surge to 38.9–72.6%. The pursuit of zero-waste material circularity inadvertently amplifies highly dispersive, respirable dust hazards in downstream sectors, necessitating targeted occupational exposure controls. Full article

Cadmium is a toxic heavy metal classified by the International Agency for Research on Cancer as a human carcinogen and recognized as an endocrine-disrupting chemical. The present study aimed to evaluate tissue-specific susceptibility to cadmium-induced oxidative damage to membrane lipids (lipid peroxidation, LPO) and to assess the antioxidative effects of melatonin in porcine tissue homogenates representing endocrine (the thyroid and the ovary) and non-endocrine (the liver, the kidney, and the brain) organs. Homogenates were incubated with cadmium chloride (CdCl₂; 2.5–1000 µM) without/with melatonin (0.1–5.0 mM). Lipid peroxidation was assessed spectrophotometrically by measuring malondialdehyde + 4-hydroxyalkenals (MDA + 4-HDA) levels. Cadmium significantly increased LPO in the liver (2.5–1000 μM) and in the kidney (25–1000 μM), whereas no prooxidative effect was observed in endocrine tissues or in the brain. Liver damage was mitigated by melatonin doses as low as 0.1 μM across the 250–1000 μM cadmium range, while protection in the kidney was limited to higher melatonin concentrations (2.5–5.0 mM) against damage induced by 100–1000 μM cadmium concentrations. The findings demonstrate pronounced tissue-specific differences in susceptibility to cadmium-induced oxidative stress and support the potential of melatonin as a preventive agent against heavy metal-induced oxidative stress, particularly in non-endocrine organs. Full article

Landfill leachate represents a long-term source of contamination that may significantly affect groundwater and receiving water bodies through the migration of organic, inorganic, and toxic pollutants. This study evaluated the long-term migration of landfill leachate and its potential environmental impacts using the LandSim Release 2 probabilistic software model applied to two municipal waste landfills in the Republic of Serbia: the regional sanitary landfill “Gigoš” in Jagodina and the sanitary landfill “Meteris” in Vranje. The modelling framework integrated laboratory leachate analyses, hydrogeological conditions, engineered barrier system characteristics, and receptor-oriented contaminant transport assessment. Model validation was performed through comparison of simulated and laboratory-measured concentrations. Two scenarios were analyzed for each site: an engineered sanitary landfill scenario with a functional containment system and a conservative barrier-failure scenario representing complete loss of engineered barrier functionality. Ten representative leachate parameters were included, covering nitrogen compounds, inorganic ions, toxic substances, and heavy metals/metalloids. The results showed that engineered protection systems significantly delay contaminant migration and reduce receptor concentrations, while barrier-failure conditions lead to earlier pollutant breakthrough and higher environmental risk. The simulations demonstrated that under the engineered sanitary landfill scenario, receptor concentrations of all analyzed contaminants remained below the corresponding maximum allowable concentrations, with contaminant migration occurring only after several centuries. In contrast, the conservative barrier-failure scenario resulted in substantially earlier contaminant breakthrough, with nitrogen compounds and phenols representing the greatest environmental concern due to their rapid migration and exceedance of regulatory thresholds, while the “Meteris” landfill generally exhibited higher receptor concentrations than the “Gigoš” landfill. These findings highlight the importance of predictive modelling and long-term monitoring for sustainable landfill management and groundwater protection. Full article

Water resources are essential for human well-being. However, water pollution is a major global problem with significant implications for the environment and public health. To address these challenges, this study presents an integrated perspective on water pollution by correlating pollution sources, transport pathways, exposure routes, and associated risks to human health. The methodology combined a systematic review conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines with a bibliometric analysis performed by using VOSviewer version 1.6.19, a software tool for constructing and visualizing bibliometric networks. A total of 332 publications published between 2015 and 2025 were retrieved from the Scopus and Google Scholar databases and met the PRISMA eligibility criteria. The findings indicate that both natural and anthropogenic sources contribute to water contamination, introducing pollutants such as heavy metals, pesticides, pharmaceutical residues, microplastics, and pathogenic microorganisms with potential human health impacts. Bibliometric analysis revealed a transition from conventional water quality assessments toward integrated approaches emphasizing health risks and environmental interactions. The study further identified important knowledge gaps regarding contaminant mixture effects and synergistic toxicity, which remain insufficiently addressed in current scientific and regulatory frameworks. These findings highlight the need for strengthened regulatory strategies, advanced treatment technologies, and evidence-based water governance to support environmental sustainability and public health protection. Full article

The contamination of aquatic environments by cadmium and other toxic heavy metals represents a major environmental concern requiring efficient and operationally sustainable remediation strategies. In this work, iron oxide materials were synthesized through a microwave-assisted hydrothermal method and evaluated for Cd(II) removal from aqueous systems. Different precursor compositions and organic additives were initially screened in order to identify the most suitable adsorbent formulation. The selected Fe-Tart material was characterized by FTIR, SEM-EDS, and XRD analyses, revealing hydroxylated and poorly crystalline iron oxide structures with heterogeneous surface organization. Batch adsorption experiments were performed under controlled conditions to investigate the influence of pH and equilibrium adsorption behavior, while adsorption data were analyzed using Langmuir and Freundlich isotherm models. Cd(II) uptake showed strong pH dependence, with adsorption progressively increasing from acidic to near-neutral conditions and reaching approximately 80% removal at pH 7–8. The Langmuir model provided the best fitting results (R² = 0.988), suggesting preferential occupation of energetically comparable surface sites with a maximum adsorption capacity of 6.51 mg g⁻¹. The adsorption behavior was interpreted within a pH-dependent surface complexation framework involving hydroxylated iron oxide surfaces. Although the adsorption capacity remained lower than that reported for some highly engineered adsorbents, the results indicate that microwave-assisted synthesis may provide a relatively simple and rapid route for preparing iron oxide-based materials potentially applicable to water remediation systems. Full article

Introduction: Heavy metal contamination in water represents a major environmental and public health challenge because toxic ions frequently occur as complex multi-species mixtures rather than isolated pollutants. This study presents a numerical design and optimization of a surface plasmon resonance (SPR) sensor based on a LaF/Au/BaTiO₃/WS₂ heterostructure for monitoring refractive-index changes associated with mixed heavy metal ions in aqueous media. Methodology: The optical response of the multilayer sensor was evaluated using the transfer matrix method under TM-polarized illumination at 633 nm. Systematic optimization was performed for the prism substrate, Au thickness, dielectric oxide layer, and 2D nanomaterial interface. The final configuration consisted of a LaF prism, 50 nm Au film, 2.0 nm BaTiO₃ spacer, and 0.80 nm WS₂ monolayer. Sensor performance was assessed using resonance-angle shift, sensitivity, detection accuracy, quality factor, figure of merit, FWHM, attenuation, and estimated limit of detection. Results and Discussion: The optimized LaF/Au/BaTiO₃/WS₂ configuration produced stable simulated SPR responses across single, binary, quaternary, and five-ion heavy metal matrices. The WS₂ monolayer provided the highest angular displacement among the evaluated 2D materials, while BaTiO₃ improved field confinement and limited optical damping in the numerical model. The configuration maintained attenuation near 1.6%, FWHM values around 7.9°, detection accuracy between 0.030 and 0.032 deg⁻¹, and model-based refractometric LoD values down to 3.49 × 10⁻⁵ RIU under the assumed angular-resolution criterion. Conclusions: The proposed LaF/Au/BaTiO₃/WS₂ SPR configuration provides a numerical framework for label-free monitoring of refractive-index changes associated with complex heavy-metal-ion mixtures in contaminated water. Experimental fabrication and testing are required to validate the simulated performance. Full article

Soil contamination around iron ore complexes in semiarid zones is usually described by total metal concentrations, which underestimate the labile mobile pool. At the Sokolovka-Sarbai mining and beneficiation complex (SSGPO, Northern Kazakhstan), total (EPA 3051A) and mobile (neutral NH₄OAc, pH 7) forms of ten heavy metals were analyzed in 87 site-horizon composites (29 sites × 3 pits × 3 horizons; 261 field samples). Descriptive indices flag Co as the only moderately contaminated element (I_geo 1.16) and Mn as the only one in persistent deficit (Kc_total 0.62); Co and Mn show the largest mobility-factor increments above background (Δ_MF +17.8 and +22.3 p.p.). The priority toxic elements As, Cd and Pb remain at or near depth-matched background in the total fraction (median Kc_total 0.98–1.09; I_geo < 0 for all three), although Pb shows a moderate mobile-fraction enrichment (median Kc_mobile 2.6); mercury was not among the ten metals analyzed. Factor analysis of mobile forms resolves two independent sources (F1-siderophile Cr-Ni-Fe-Mn-Co; F2-Zn-dominant, non-sphalerite) and a humus-driven sorption pool (F3), coherently localized in the dump2A-pit2 sector; mobile-fraction attribution greatly outperforms the total fraction (21 vs. 0 FDR-significant trends). The raw Mn-deficit-Co-mobility correlation (ρ = −0.54) is fully mediated by humus (partial ρ = +0.05). Total Mn deficit and enhanced Co lability are therefore interpreted as coupled consequences of a single humus-Ca-pH Kastanozem geochemistry rather than a causal “Mn-buffer depletion → Co mobilization” chain. Because the dataset is cross-sectional, this distinction remains correlational; sequential fractionation and mineralogical verification are priorities for future work. Full article

This study examined the removal of toxic heavy metals Pb²⁺ and As⁵⁺ from wastewaters by applying a waste nut biomass for adsorption. The waste material was steam-activated and further modified with zinc nitrate tetrahydrate to improve its affinity for arsenate. The adsorption performance was evaluated across a range of contact times, sorbent dosages, initial metal concentrations, and pH levels, for both single-metal and mixed-metal systems. When the raw material was modified by Zn, the maximum uptake of As⁵⁺ reached a value of 51 mg/g, at a sorbent dosage of 2 g/L. In binary metal solutions, the biochar exhibited maximum capacities of 25.5 mg/g for Pb²⁺ and 48.5 mg/g for As⁵⁺, indicating minimal competition between the two ions for adsorption sites on the biochar surface. Full article

Nanoplastics (NPs) and heavy metal cadmium (Cd) are common co-existing pollutants in freshwater environments, but their combined toxic effects on the liver of herbivorous economic fish remain unclear. In this study, grass carp (Ctenopharyngodon idella) were exposed to polystyrene nanoplastics (PS-NPs, 100 nm) and/or Cd to investigate their individual and combined effects on hepatic toxicity. The results revealed that co-exposure interactively suppressed interleukin-10 (IL-10) expression and heme oxygenase-1 (HO-1) antioxidant response, and induced more severe hepatic necrosis, melanization, and fibrinoid necrosis, with the highest integrated biomarker response index and extensive disruption of lipid and steroid metabolism pathways. This study clarified the toxicological interaction of NPs and Cd on the liver of grass carp, and provided a theoretical basis for understanding the combined toxicity of NPs and heavy metal pollution in extreme contamination scenarios or accidental pollution events. Full article

The oxidative potential (OP) of atmospheric particulate matter serves as an effective indicator for assessing the health risks posed by reactive oxygen species (ROS). Existing studies have mainly focused on conventional particulate matter including PM_2.5, whereas systematic investigations into the OP of road dust in coal–resource–based cities are still limited. Taking Huainan City, China as the study area, this paper explored the characteristics and influencing factors of OP in water–soluble fractions of road dust from different functional zones. The results indicated that the OP of water-soluble fractions in road dust from Huainan City was 0.162 ± 0.079 pmol/min/μg, with the value in the coal mining zone being significantly lower than that in the commercial and industrial zones. The average concentration of water–soluble organic carbon (WSOC) was 67.3 ± 59.4 mg/kg, with lower levels observed in the coal mining and power plant zones. WSOC was primarily dominated by fulvic acid–like (C1) and tryptophan–like (C2) components. C1 prevailed in coal mining, power plant, and other functional zones, whereas C2 was dominant in commercial, park and residential zones. Overall, the WSOC showed a mixed-source signature dominated by endogenous sources and characterized by a low degree of humification. The total concentration of water–soluble heavy metals in road dust was 43.46 mg/kg, dominated by Fe, Sr, Cu, Ba, and Mn, with relatively lower concentrations observed in the industrial and coal mining zones. The influencing factors of OP exhibited differentiation among functional zones: in industrial zones, it was regulated by As, Mn, TC (total carbon), WSOC and its fluorescent components, while in non-industrial zones, it was closely associated with Co, TC, and WSOC. These findings indicate that road dust toxicity and its key chemical drivers in coal mining and power plant zones of coal resource–based cities exhibit distinctive characteristics. This study provides a scientific basis for the precise management of road dust pollution and the prevention of associated health risks. Full article

Semiconductor–biological hybrid systems (SBHS) have emerged as a disruptive technology for solar-driven chemical manufacturing, effectively bypassing the thermodynamic bottlenecks of natural photosynthesis. However, the aggressive pursuit of record-breaking solar-to-chemical conversion efficiencies has inadvertently fostered an efficiency trap. A profound interdisciplinary schism exists wherein the acute environmental toxicity and long-term interfacial instability of these hybrid architectures are frequently overlooked. This review provides a critical appraisal of the oft-ignored environmental risks inherent in current SBHS designs. We systematically dissect the heavy metal leaching toxicity of first-generation inorganic photosensitizers and unveil the complex, bidirectional degradation mechanisms at the abiotic–biotic interface. Specifically, we highlight the dual threats of photogenerated reactive oxygen species inducing cellular oxidative stress and active, microbially induced material dismantling via reductive dissolution driven by extracellular electron transfer. To navigate beyond this purely performance-driven paradigm, we propose a multidimensional, standardized evaluation matrix that systematically balances catalytic efficiency with biological safety and life-cycle sustainability. Ultimately, this review offers a comprehensive roadmap to transition biohybrid platforms from fragile laboratory concepts into robust, scalable, and ecologically benign negative-emission technologies. Full article

Rice, a staple food for over half of the global population, faces significant threats from environmental stressors such as heavy metal (HMs) contamination, notably cadmium (Cd) and arsenic (As), and increasing drought severity, exacerbated by climate change. These challenges not only compromise rice yield and quality but also pose serious food safety risks due to HM accumulation in grains, endangering human health. Modified biochar (MBC), a carbon-rich material derived from the pyrolysis of organic matter with post-treatment enhancements, has emerged as a strategy to address these dual stressors. MBC application (typically 5–20 t ha⁻¹) reduces Cd and As bioavailability in paddy soils by 40–60% and decreases metal accumulation in rice grains by 20–85% compared to the control. Under drought conditions, MBC improves soil water-holding capacity by 11–45% and enhances crop water use efficiency by 15–24%, leading to yield improvements of 20–50% under moderate water deficit. Furthermore, MBC supports nutrient availability, fosters robust root systems, and enhances soil aeration, collectively improving rice growth under adverse conditions. Beyond its agronomic benefits, MBC provides a framework for addressing multiple challenges by integrating scientific innovation, policy alignment, and community participation. This approach not only reduces heavy metal toxicity and strengthens plant resilience but also enhances food security and advances Sustainable Development Goals (SDGs 2, 3, 4, 12, 13, 15, 17). By promoting environmentally sustainable agriculture and contributing to climate change mitigation, MBC represents a transformative tool for ensuring sustainable rice production in the face of global challenges. Full article

Heat and Cd²⁺ stress are major environmental challenges for marine benthic invertebrates. This study examined their combined effects on growth, physiology, and transcriptomic responses in the peanut worm (Sipunculus nudus). After 30 days, Cd²⁺ reduced survival at 26 °C without significantly affecting growth, whereas at 32 °C, both survival and growth declined with increasing Cd²⁺ concentration, indicating that heat stress exacerbates Cd²⁺ toxicity. Cd accumulation increased with exposure concentration but was not affected by temperature. Heat stress increased immune (AKP) and antioxidant (SOD, CAT) enzyme activities, although significant increases in SOD and CAT were observed only under Cd²⁺ exposure. AKP activity rose at low Cd²⁺ concentrations and fell at high Cd²⁺ concentrations at 26 °C, whereas no significant difference occurred at 32 °C between 0 and 0.25 mg/L Cd²⁺. At the same temperature, SOD and CAT activities were significantly higher under high Cd²⁺ exposure than under low Cd²⁺ exposure. Transcriptome analysis showed that Cd²⁺ exposure activated longevity-related pathways, protein processing, and translation initiation. Heat stress activated Jak-STAT signaling and endoplasmic reticulum protein processing while inhibiting the ribosome pathway. Under combined stress, pathways related to xenobiotic metabolism, nutrient digestion and absorption, and amino acid derivative metabolism were broadly suppressed. These results highlight that heat stress exacerbates Cd²⁺ toxicity, affecting growth, enzyme activity, and transcriptomic responses, and provide insights into the adaptive strategies of marine benthic organisms under the combined pressures of climate change and heavy metal pollution. Full article

Heavy metal pollution poses a significant threat to industrial and agricultural ecosystems; however, thorough research on the coupled risks and migration mechanisms of heavy metals within soil-groundwater systems in arid-region industrial parks remains limited. This study systematically collected 312 surface soil samples and 239 groundwater samples from typical chemical industrial parks in Xinjiang, northwestern China. The pollution levels of six typical heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) were quantitatively evaluated utilizing the Single Pollution Index (P_i), Nemerow Pollution Index (P_N), and Potential Ecological Risk Index (RI) for soil and the improved Heavy Metal Contamination Index (HCI) for groundwater. Additionally, GIS mapping and the Positive Matrix Factorization (PMF) model were integrated to delineate spatial distributions and primary emission sources. The assessment results indicated overall moderate pollution risks for Cd, Cu, and Ni in the soil, and for Cd, Pb, Cr, and Ni in the groundwater. Notably, Cd emerged as the primary risk contributor across both media. The RI identified Cd as the element posing the highest soil toxicity risk (with a mean RI of 53.57), while the HCI revealed that specific industrial zones face severe contamination levels (HCI > 4500), predominantly driven by Cd and Pb. GIS analysis illustrated a distinct distance–decay diffusion pattern emanating from industrial point sources. Crucially, PMF source apportionment demonstrated divergent contamination pathways: surface soil heavy metals (e.g., Cr, Cu, Pb, Zn) were primarily governed by top-down local industrial emissions (52.5%), whereas groundwater contamination was largely dictated by regional groundwater flow carrying mixed agricultural and natural geogenic inputs (75%). Furthermore, Pearson correlation analysis revealed a prevalent weak or negative correlation between heavy metal concentrations in the two media, suggesting a spatial “decoupling” of their contamination pathways. This phenomenon is likely driven by a dynamic “retention-leaching” mechanism within the arid vadose zone, where alkaline pH and high clay content act as a hydrochemical barrier impeding vertical migration. These findings underscore that soil and groundwater in arid industrial regions should be managed as distinct hydrochemical systems, providing a robust scientific basis for targeted remediation and the sustainable redevelopment of industrial brownfields. Full article