Search Results (1,786)

The production of green hydrogen via aqueous electrolysis of hydrogen sulfide (H₂S) holds significant potential to address challenges related to sustainable energy generation and environmental protection. The electrocatalytic splitting of water polluted with highly toxic H₂S is attractive for industrial applications because the process: (i) is less power-consuming than direct thermal H₂S decomposition; (ii) achieves high Faradaic efficiencies for hydrogen production; and (iii) yields elemental sulfur as an added-value by-product. This review covers a brief discussion on sulfide-containing water sources and electrochemical methods for hydrogen production from H₂S, specifically Direct, Indirect, and Electrochemical Membrane Reactor (EMR) systems. To become commercially and economically attractive, these approaches require improvements in electrolysis efficiency through the development of low-cost electrode materials that are resistant to sulfur poisoning and corrosion, while possessing high catalytic activity, enhanced stability, and durability. Early research focused on carbon-based materials combined with noble metal oxides, transition metal compounds, and related materials. Since their practical performance is limited, investigations have shifted toward nanostructured electrocatalysts with unique crystal structures and designs, which show significantly improved efficiency for H₂S electrolysis. This review highlights the potential of H₂S electrolysis for hydrogen production, giving special attention to recent advancements in electrode materials. Full article

Metal(loid) contamination is a persistent environmental stressor in terrestrial ecosystems, yet field-based evidence linking cumulative soil contamination to physiological responses in social insects remains limited. In this study, we investigated an industrial pollution gradient by measuring soil concentrations of potentially toxic elements across multiple sites and integrating multi-element exposure into a cumulative pollution index. Two ant taxa, Lasius niger (Linnaeus, 1758) and Tetramorium cf. caespitum (Linnaeus, 1758), were sampled using a standardized field design, and biochemical endpoints were assessed to characterize antioxidant defense, thiol-based redox status, oxidative damage, and neuroenzymatic responses. Ant homogenates were analyzed spectrophotometrically for antioxidant enzymes, reduced glutathione, lipid peroxidation, protein oxidation, and acetylcholinesterase activity compared with the local low-contamination reference site. In addition, PLI showed positive site-level associations with multiple biomarkers, suggesting coordinated covariation between cumulative soil contamination and biochemical responses. Because these analyses were based on site-level mean values and direct tissue metal burdens were not measured, the findings should be interpreted as field-based associations rather than evidence of direct internal dose–response or metal-specific causality. These findings suggest that cumulative soil metal(loid) contamination is linked to integrated oxidative and neuroenzymatic stress responses in ants and support the use of ant-based biomarkers as informative tools for ecological biomonitoring under field conditions. Full article

Nanoparticles (NPs) have great potential for stimulating plant growth and development, reducing the negative impact of various types of stress on plants, and increasing the yield of agriculturally important crops. Metal oxide NPs (MONPs) have been shown to have a significant effect on the physiological and biochemical processes in plants, enhancing plant resilience. Among them, CuO, Mn_xO_x, and ZnO NPs are of particular interest because they contain elements essential for plant function. However, widespread use in agrochemistry and plant protection requires a preliminary risk assessment due to their potential phytotoxic effects. Phytotoxicity manifests through the development of oxidative stress, genotoxicity, and transcriptional disruption. A decrease in plant growth and photosynthesis, increased lipid peroxidation (LPO), and the accumulation of toxic NPs in plant tissues were also observed. Among the studied MONPs, CuO and ZnO NPs exhibit the greatest phytotoxic effects. However, the effects of MONPs are dose-dependent. Numerous studies have shown that MONPs can stimulate plant biometric parameters and productivity, as well as influence biochemical processes. MONPs have been shown to influence the functioning of the plant antioxidant system, manifested by modulating the content of reactive oxygen species (ROS), the activity of antioxidant enzymes (AOEs), and the regulation of signaling pathways mediated by ROS and reactive nitrogen species. Furthermore, MONPs influence the accumulation of proline and phenols in plant tissues. MONPs have a pronounced effect on the functioning of the plant photosynthetic apparatus, manifested by changes in pigment content, the activity of photosynthetic enzymes, and the functioning of photosystems. MONPs can improve nutrient absorption, regulate osmotic balance, and activate plant defense mechanisms. ZnO NPs are effective in mitigating salt stress. CuO and Mn_xO_x NPs have shown promise in mitigating biotic stress. Furthermore, these NPs were found to reduce the toxicity of heavy metals to plants. Overall, when used wisely, MONPs hold promise for enhancing the physiological, biochemical, and agronomic performance of crop plants under conditions of global climate change, effectively addressing food security issues. Full article

Potentially toxic elements (PTEs) in mining-impacted wetlands can transfer from soil and water to forage and grazing livestock, resulting in dietary exposure for nearby communities. In this study, arsenic (As), lead (Pb), and cadmium (Cd) were quantified in key environmental matrices (soil, surface water, and forage) and in sheep tissues (liver, kidney, and muscle) from six georeferenced grazing sites in the Ite coastal wetland (Tacna, Peru) during the dry season. Samples were acid-digested following U.S. EPA protocols and analyzed by atomic absorption spectrometry (AAS) under QA/QC procedures (certified reference materials, blanks, duplicates, and matrix spikes); matrix-specific detection and quantification limits are reported. Arsenic dominated the contamination profile (forage: 428.6 mg kg⁻¹, dry weight; soil: 48.61 mg kg⁻¹; water: 0.97 mg L⁻¹) and was detected in sheep tissues (kidney: 0.1577 mg kg⁻¹; muscle: 0.1538 mg kg⁻¹; liver: 0.0644 mg kg⁻¹). Lead and cadmium were <LOQ in muscle and liver but were measurable in kidney (Pb: 0.0415 mg kg⁻¹; Cd: 0.0011 mg kg⁻¹). To support the interpretation of trophic transfer, screening transfer/bioaccumulation metrics (soil-to-forage, forage-to-tissue, and water-to-tissue) were calculated. Human dietary exposure was screened using estimated daily intake (EDI), hazard quotient (HQ), and margin of exposure (MOE). Because arsenic speciation was not measured, inorganic arsenic (iAs) risk was evaluated as a conservative upper bound (100% iAs) and through sensitivity scenarios (10–50% iAs). Under a high-meat-consumption scenario (300 g day⁻¹), the upper-bound assumption yielded HQ = 2.2 and MOE = 0.46; however, scenario analyses indicate that risk conclusions are highly dependent on the assumed iAs fraction. Overall, the results identify arsenic as a priority contaminant and support targeted grazing management, the provision of low-arsenic water sources, and remediation and monitoring actions to reduce exposure in vulnerable rural communities. Full article

A growing body of epidemiological and toxicological evidence indicates that exposure to toxic elements (TEs), including As, Cd, Cr(VI), Pb, and Hg, is associated with a wide range of adverse health outcomes, including cancer, neurological and cardiovascular diseases. Given their widespread presence and toxicity, understanding the factors underlying inter-individual differences in susceptibility is essential, as not all exposed individuals develop the same health effects. Genetic variability, particularly single-nucleotide polymorphisms (SNPs), is increasingly recognized as a key determinant of individual responses to TE exposure. Variants in genes involved in metal transport, detoxification, and DNA repair, including DMT1, GSTP1, MT2A, hOGG1, and XRCC1, may influence internal dose and biological effects and have been proposed as potential susceptibility markers. However, current evidence remains inconsistent due to small sample sizes, heterogeneous exposure assessments, and limited considerations of ethnic diversity and gene–environment interactions. Future research should prioritize large and well-characterized populations integrating detailed exposure and lifestyle data. This review focuses on genetic susceptibility and gene–environment interactions in TE exposure, with particular emphasis on SNPs as key modulators of individual risk. It summarizes major toxic metals, reviews epidemiological evidence of the associated health risks, and highlights the role of genetic background in modulating TE-induced toxicity. Full article

This study conducts a cradle-to-gate Environmental Life Cycle Assessment (E-LCA) of tea production in Sri Lanka, comparing smallholder and estate-owned plantations processed by Orthodox and Crush–Tear–Curl (CTC) methods. Unlike most tea LCA studies that treat cultivation as a single undifferentiated phase, this work explicitly incorporates the perennial nature of tea by using a modular life cycle framework that separates the agronomic stages alongside factory processing up to the packed-tea gate. This approach allows a more precise allocation of long-term environmental burdens over the entire productive lifespan of the tea plant, addressing a methodological gap in the literature. Four production scenarios were evaluated: Smallholder-Orthodox, Smallholder-CTC, Estate-Orthodox, and Estate-CTC, with the functional unit set to 1 tonne of processed tea. Primary data were gathered through structured surveys of 30 plantations (25 smallholders, 5 estates) and 5 tea factories, supplemented by secondary data from Ecoinvent v3.11 and national statistics. The CML-IA Baseline method in SimaPro v9.5 was applied to characterize impacts across eight impact categories: global warming potential (GWP), abiotic element depletion, fossil fuel depletion, acidification, human toxicity, terrestrial ecotoxicity, freshwater ecotoxicity, and eutrophication. Results indicate that Smallholder-Orthodox systems have the highest GWP (3304 kg CO₂ eq per tonne), whereas Estate-CTC systems show a lower GWP (2894.87 kg CO₂ eq). Acidification potential ranges from 47.21 kg SO₂ eq for Smallholder-Orthodox to 41.25 kg SO₂ eq for Estate-CTC. Overall, the findings suggest that the scale of plantation management has a greater impact on environmental performance than processing technology, highlighting the need to focus sustainable practices on the cultivation stage, exactly where the perennial crop modeling approach used here provides the greatest analytical benefit. Full article

Peloids are natural materials widely used in balneotherapy and dermatological treatments because of their physicochemical and mineralogical properties. Despite Serbia’s long tradition of spa-based pelotherapy, comprehensive data on the chemical and radiological characteristics of local peloids remain limited. In this study, peloid samples from 13 spa locations across four regions of Serbia were systematically investigated. The aim was to determine their physicochemical properties, elemental composition, and natural radioactivity, to assess their suitability and safety for therapeutic use. The analyzed samples exhibited pronounced variability in pH (6.59–9.52), electrical conductivity (77.5–6610 μS/cm), salinity (below detection limit to 4%), and total dissolved solids, reflecting diverse geological and hydrochemical properties. Inductively coupled plasma optical emission spectrometry revealed site-specific variations in macro- and microelements, influenced primarily by local lithology and sedimentary environments, with limited indications of anthropogenic inputs. Gamma spectrometric analysis showed that the activity concentrations of naturally occurring radionuclides (²²⁶Ra, ²³²Th, ⁴⁰K, ²³⁸U, ²³⁵U, ²¹⁰Pb) were within ranges commonly reported for therapeutic muds worldwide, while anthropogenic ¹³⁷Cs was generally low. Radiological hazard indices were below internationally recommended safety limits. A preliminary screening of dermal exposure to potentially toxic elements indicated no significant noncarcinogenic risk (HI < 1) and acceptable carcinogenic risk (TCR) levels. Overall, this study provides a comprehensive chemical and radiological baseline for Serbian peloids, supporting their safe use in controlled therapeutic and wellness applications and highlighting the importance of site-specific characterization for quality assessment. Full article

Nanoparticles (NPs) of urban dust can be hazardous to human health due to the possibility of a high accumulation of potentially toxic elements (PTEs), high penetration ability into organisms, and their ability to cause injury to cells, tissues, and organs. The composition of NPs of urban dust may vary during the year; however, there are so far no studies on the seasonal changes in their elemental composition and related ecological and health risks. The current work was carried out using samples of urban dust from Moscow, the largest megacity in Europe, collected in spring, summer, and autumn. It was found that NPs of urban dust are polluted by PTEs, namely W, Bi, Hg, P, S, Sn, Mo, Cu, Cd, Pb, Sb, and Zn. The highest pollution and ecological risks were found in NPs of urban dust collected in summer (RI = 592) as compared to autumn (RI = 399) and spring (RI = 231). The same regularity was observed for health risks. The highest possible cancerogenic risk was found in summer NPs (CTCR = 3.0 × 10⁻⁴) followed by autumn NPs (CTCR = 2.5 × 10⁻⁴) and spring NPs (CTCR = 3.5 × 10⁻⁵). However, the difference between mean values obtained for the three seasons was not statistically significant. Additionally, it was demonstrated that vehicle emissions are one of the main sources of pollution of NPs, and their intensity does not significantly change throughout the year in Moscow. The results obtained offer new insights into the regularities of seasonal variations in elemental composition, pollution, and related ecological and health risks of NPs of urban dust. Full article

The evaluation of potentially toxic element concentrations (PTEs) in soils and plants is essential for understanding environmental quality and potential human exposure in areas affected by intense anthropogenic activity. This study addresses a research gap in the Valencian Region, focusing on soil–plant interactions of PTEs in urban and industrial environments. We assess the status of the soil–plant system in a region of the Valencian Community (eastern Spain) subjected to strong urban, industrial and agricultural pressure. A total of 55 soil samples and 47 plant samples were collected from agricultural, urban and industrial sites and analysed for soil properties, major elements (Al, Mg, Fe) and PTEs (As, Cd, Co, Cr, Cu, Li, Mn, Ni, Sr, V and Zn). Land use significantly influenced soil physicochemical characteristics, with clear differentiation among environments. Soil texture and organic matter were the main factors controlling element retention, while Al, Fe and Mg dominated the geochemical composition, consistent with Mediterranean calcareous soils. Correlation analyses revealed strong co-occurrence patterns among lithogenic elements (e.g., Fe-Al, r = 0.917 p < 0.01), soil texture and chemical properties, indicating a shared origin and preferential retention in the fine fraction and soil organic matter. Contamination indices identified potential environmental risk mainly associated with Cu, Pb, Sr and Zn, particularly in densely populated areas. Mean concentrations of Cd, Cr, Cu, Pb and Zn were, respectively, 0.63 mg kg⁻¹, 42.25 mg kg⁻¹, 31.49 mg kg⁻¹, 56.91 mg kg⁻¹ and 76.08 mg kg⁻¹. These elements exceeded Spanish regulatory reference values in several soils. Bioaccumulation indices indicated notable plant uptake of As, Sr and Zn, highlighting their potential for trophic transfer. Full article

The term ‘superfoods’ refers to a rapidly expanding group of food products that have gained increasing global interest due to their high nutritional value and association with health-oriented dietary patterns. Many superfoods, particularly grains and seeds, are rich sources of essential minerals, plant protein, dietary fibre, and bioactive compounds, making them valuable components of gluten-free, vegetarian, and vegan diets. The aim of this study was to evaluate the elemental composition of selected superfood grains and seeds and to verify the reliability of manufacturers’ declarations. The analyses confirmed that the investigated samples possess a rich macro- and trace elemental composition, with pronounced differences among product groups. Based on median concentrations, pumpkin and hemp seeds were characterized by generally high levels of Mg, K, P, Fe, Mn, and Zn, whereas chia seeds exhibited notably elevated Ca content. In contrast, quinoa and amaranth showed comparatively lower elemental concentrations. Most of the results obtained for the analysed products are within the permissible deviation from the value declared on the packaging, as specified in the relevant EU regulations. The presence of potentially toxic elements, including Al, Pb, and Cd, was also detected. Cadmium accumulation was of particular concern in flax seeds, where all samples exceeded the limit of quantification and approached permissible levels. Principal component analysis revealed clear clustering patterns, indicating similarities between amaranth and quinoa, as well as between hemp and pumpkin seeds, while chia and flax seeds formed distinct groups. These results highlight both the nutritional potential of superfoods and the necessity for independent verification of their elemental composition. Full article

Fluoroquinolone antibiotics, like danofloxacin, are considered as crucial veterinary drugs due to their high antibacterial potential, a broad spectrum of activity and good pharmacological properties. However, owing to the widespread use of this group of pharmaceuticals, microbial resistance to them is becoming a serious worldwide concern. In the present study, novel silver and copper complexes of danofloxacin were prepared and characterized using ¹H NMR, ¹⁹F NMR and IR spectroscopy, ESI-MS spectrometry, and elemental analysis. The antimicrobial properties of the obtained complexes were determined against selected bacterial and fungal strains, including yeast and conidia-forming fungi. Additionally, toxicities of danofloxacin metal-based complex solutions were assessed toward eukaryotic cells. The obtained results indicate that silver(I) and copper(II) complexes of danofloxacin exhibit good antimicrobial activity against bacteria that are important from the veterinary point of view, like Listeria monocytogenes or Campylobacter jejuni, in concentrations which are not cytotoxic. The MBC values of metal-based danofloxacin complexes for the mentioned strains were 1.5 times lower than those obtained for danofloxacin. Additionally, the solution of the novel silver–danofloxacin complex was found to have a fungicidal effect against the studied Candida and Aspergillus strains. Full article

Medicinal plants represent important sources of bioactive compounds with beneficial effects on human health. However, many medicinal species are ruderal plants capable of growing in soils with elevated contents of potentially toxic elements (PTEs) such as Cd, Pb, and Zn. In addition to the potential accumulation of PTEs in plant biomass, the response of the plant metabolome—including bioactive substances with beneficial health effects—to elevated PTE levels in plants should also be considered. The potential impact of soil PTEs on the plant metabolome was investigated in three widely used medicinal plants, Taraxacum sp., Achillea millefolium, and Hypericum maculatum, sampled in an area polluted with PTEs. The total soil contents of the PTEs ranged between 7.7 and 65 mg/kg for Cd, 1541 and 3897 mg/kg for Pb, and 245 and 6553 mg/kg for Zn. A qualitative analysis of the whole plant metabolomes of the three plant species indicated close interrelationships between the selected metals and bioactive substances. Subsequently, a model pot experiment was conducted in which Taraxacum sp. plants were cultivated in three soils with stepwise increasing Cd, Pb, and Zn contents, and selected bioactive compounds were quantified. The results showed a decrease in the concentrations of some phenolic compounds in the aboveground parts of Taraxacum sp. grown in extremely polluted soil, supporting the hypothesis that stress induced by PTEs may affect the metabolic pathways of these compounds. In contrast, higher levels of phenolic compounds were observed in Taraxacum sp. roots grown in moderately contaminated soil, suggesting that milder soil contamination may activate defence mechanisms and stimulate phenolic metabolism. However, although the contents of bioactive compounds in plants indicate an improvement of the quality of these medicinal plants, the elevated element contents in the plant biomass can represent a potential risk for consumers. Full article

Treated wastewater (TWW) reuse mitigates water scarcity but may induce soil salinization and trace metal accumulation if improperly managed. This field study evaluated the combined effects of irrigation water quality (TWW vs. well water) and irrigation method (surface vs. subsurface drip irrigation, SDI) on soil chemical properties, okra growth, yield, and nutrient/trace element dynamics under semi-arid Mediterranean conditions. Soil pH remained stable across treatments. Electrical conductivity was not significantly affected by water quality but increased in deeper layers under surface drip irrigation, indicating salt migration. SDI promoted more uniform nutrient distribution and favored Na⁺ displacement toward deeper layers, reducing root-zone exposure. Cations stratified vertically, with Ca²⁺, Mg²⁺, and K⁺ concentrated in surface layers and Na⁺ at depth. Water quality exerted a stronger influence than irrigation method. The fertilizing effect of TWW significantly enhanced plant height (53%), leaf dry matter (43%), aboveground biomass (81%), and fruit yield (16.3%). When combined with SDI, TWW improved irrigation water use efficiency by 20%. Although fruit Cd concentrations increased under TWW irrigation, all trace metals remained below international food safety standards. These findings indicate that integrating TWW with SDI enhances productivity and water use efficiency while maintaining short-term food safety, though long-term monitoring remains essential. Full article

The rising global demand for lithium has led to substantial accumulation of lithium slag, a by-product of lithium carbonate production and a potential environmental contaminant. Leachates from this material contain various metal elements and may pose risks to ecosystems and organismal health. However, research on its neurotoxicity and underlying mechanisms remains limited. In this study, zebrafish embryos at 6 h post-fertilisation were exposed to varying concentrations of lithium slag leachate for 7 days. The leachate contained multiple metal ions (Li, Fe, Mn, Ni, Zn, As, Cr, Cu, Hg, Cd, Pb, etc.). Following exposure, significant metal accumulation was observed in larvae, accompanied by developmental malformations (yolk sac oedema, cardiac haemorrhage, and uninflated swim bladders). Behavioural assessment revealed reduced swimming distance and velocity, along with disrupted circadian rhythms. Biochemical analyses showed elevated Reactive oxygen species (ROS), Superoxide dismutase (SOD), Catalase (CAT), and Malondialdehyde (MDA), alongside decreased Glutathione (GSH), indicating oxidative stress. Transcriptomic analysis confirmed downregulation of core circadian genes. Neurotransmitter assays revealed decreased acetylcholine (Ach), noradrenaline (NE), and dopamine (DA), with increased gamma-aminobutyric acid (GABA) and serotonin (5-HT). These findings demonstrate that lithium slag leachate induces oxidative stress, circadian disruption, and neurobehavioural toxicity in zebrafish, providing important evidence for environmental risk assessment. Full article

Copper flotation tailings are produced in large quantities during ore beneficiation and smelting, yet remain underutilized and can act as persistent sources of potentially toxic elements. Here, we combined XRD-based mineralogical characterization, ICP-OES quantification, Tessier sequential extraction, and pH-dependent batch leaching to elucidate metal occurrence, mobility, and associated ecological risk in tailings from Tongling, Anhui Province. This study systematically analyzed the mineral composition, potentially toxic elements content, chemical fractions, leaching behavior, and ecological risks of copper flotation tailings from the Shuimuchong tailings reservoir in Tongling, Anhui Province. XRD and XRF analyses revealed that calcite, quartz, and garnet were dominant mineral phases in the tailings. Elevated levels of Cu, Cd, Pb, Zn, and As were detected, some of which surpassed both local background concentrations and national soil quality standards. Most potentially toxic elements primarily existed in the residual fraction, indicating low mobility. Leaching experiments revealed that Zn, Cu, and As showed enhanced release under acidic conditions, making them priority risk elements during tailings acidification. Pollution index and ecological risk assessments indicated that the tailings were heavily contaminated, with Cu and Cd as the main risk contributors. The Risk Assessment Code (RAC) evaluation showed that Cd had the highest bioavailability and ecological risk. By clarifying the behavior of pollutants, this study contributes to the effective regulation of environmental hazards and the sustainable use of tailing materials. Full article