Search Results (343)

Freshwater ecosystems are increasingly exposed to metal contamination arising from natural and anthropogenic activities, potentially affecting fish physiology and ecosystem health. However, limited information is available regarding metal accumulation and associated biological responses in fish populations from Dukan Lake, northern Iraq. Therefore, this study investigated metal concentrations in water and tissues of common carp (Cyprinus carpio) and evaluated their relationships with selected fish health indicators. Water and fish samples were collected monthly from Dukan Lake, and a total of 60 fish were classified into three length groups (20–29 cm, 30–39 cm, and 40–49 cm). Metal concentrations in water, liver, and gonad tissues were analyzed using ICP-OES, while condition factor (CF), gonadosomatic index (GSI), and hepatosomatic index (HSI) were used to assess fish physiological condition. Sodium (Na), magnesium (Mg), potassium (K), iron (Fe), zinc (Zn), and barium (Ba) were detected in both water and fish tissues, with concentrations in water ranging from 50 to 7069 μg/L. In contrast, chromium (Cr), manganese (Mn), nickel (Ni), selenium (Se), silver (Ag), cadmium (Cd), antimony (Sb), lead (Pb), copper (Cu), and arsenic (As) were below detection limits. Biometric analysis revealed significant differences (p < 0.05) in the gonadosomatic index (GSI) among fish length groups, indicating size-dependent reproductive development. However, no significant relationship was observed between fish length and either the CF or HSI, suggesting relatively stable somatic condition or liver status across size classes. Correlation analysis showed no significant associations between water metal concentrations and CF or GSI. A significant positive correlation was identified between Zn concentration and HSI in the 30–39 cm length group, indicating a possible link between Zn exposure and hepatic physiological response. The findings indicate that essential elements dominate the metal profile in Dukan Lake, with limited evidence of toxic metal contamination. No major adverse effects on the general condition of the fish were observed. These results contribute to understanding metal bioaccumulation patterns and their implications for fish health in freshwater ecosystems. Full article

Cosmetic formulations containing natural or minimally processed raw materials are prone to microbial contamination, which can compromise product safety and quality. The standard ISO 11930 preservation challenge test employs a predefined set of test microorganisms, which may not adequately represent product-associated contaminants. In the present study, an adapted ISO 11930 preservation challenge test was applied to compare the antimicrobial performance of four preservative systems in an oil-in-water cosmetic formulation. In addition to the five standard reference strains, seven environmental and raw-material-associated microorganisms associated with walnut and apricot kernel shells were included. All preservative-containing formulations fulfilled the required acceptance criteria; however, marked differences in time-dependent antimicrobial activity were observed between preservative systems. Among the tested systems, the formulation containing 0.4% potassium sorbate demonstrated the most rapid and broad-spectrum antimicrobial performance across the expanded microbial panel. In contrast, combinations of potassium sorbate with sodium benzoate and benzyl alcohol showed slower antimicrobial efficacy. In conclusion, this study demonstrates that reliance solely on standard reference microorganisms may underestimate preservation risks in cosmetics that use naturally derived raw materials. The adaptive preservation challenge test is a risk assessment approach for evaluating the microbiological stability of cosmetic formulations with reduced-preservative systems. Full article

Lead (Pb) is a persistent and highly toxic heavy metal that poses significant ecological and human health risks due to its high bioaccumulation potential. In this study, nitrogen-doped biochar (NBC) was synthesized from straw-derived biochar via ball-milling and ammonium nitrate modification to remediate Pb-contaminated soil. Batch adsorption experiments demonstrated that the adsorption process was best described by the Langmuir isotherm model, indicating monolayer adsorption. X-ray photoelectron spectroscopy (XPS) revealed that Pb(II) immobilization by NBC occurred through multiple mechanisms, primarily precipitation and complexation with hydroxyl and pyrrolic-N functional groups. Subsequent pot experiments confirmed that NBC outperformed pristine biochar (BC) in reducing Pb bioavailability. This superior performance was attributed to the ability of NBC to increase soil pore water pH and significantly decrease soil redox potential (Eh). Moreover, compared to the control, a 5% NBC treatment (NBC2) significantly increased soil organic matter (SOM) by 136.24% while concurrently increasing soil available nitrogen (SAN), phosphorus (SAP), and potassium (SAK) by 46.91%, 75.72%, and 42.79%, respectively. Microbiological analyses indicated that NBC application enhanced soil alpha diversity (Chao1, ACE, and Shannon indices) and enriched beneficial bacterial phyla, such as Proteobacteria and Firmicutes. Random forest analysis identified the acid-soluble Pb fraction and SOM as the main drivers of bacterial operational taxonomic unit (OTU) composition. Specifically, NBC increased the relative abundance of the family Hungateiclostridiaceae, which may promote soil sulfide production and facilitate the precipitation of Pb into highly insoluble forms, further reducing its mobility and toxicity. Collectively, these findings demonstrate that NBC is a promising soil amendment that leverages both physicochemical and microbial pathways to immobilize Pb, mitigate environmental toxicity, and restore soil ecological health. Full article

Infectious prion adsorption on metal, minerals, wood, and plastic is well documented, raising the specter of food safety hazards for meat packing workers, sport hunters, and consumers. We previously demonstrated that sodium hypochlorite, and to a lesser extent, potassium peroxymonosulfate, and hypochlorous acid can decontaminate prion-contaminated nonporous surfaces. However, the extent to which chemical aging of surfaces affects subsequent recoverable prion seeding activity is unknown. In this study, we investigated the potential for four chemical decontaminants known for their anti-prion activity (sodium hypochlorite [bleach], hypochlorous acid [Briotech], potassium peroxymonosulfate [Virkon-S], and Wex-Cide-128) to alter the surfaces of steel knives and the subsequent prion decontamination efficacy of each. We found that hypochlorous acid, sodium hypochlorite, and potassium peroxymonosulfate corrode the surfaces of steel knives, resulting in significant physical alterations. Knives exposed to hypochlorous acid exhibited the most substantial corrosion (rust), which is consistent with its oxidizing effects. Oxidation of the knife surface was corroborated by complementary energy-dispersive X-ray spectroscopy data trends. Scanning electron microscopy data indicate corrosion is apparent after minimal exposure to oxidizing agents. Finally, we used the real-time quaking-induced conversion assay on swabs collected from chemically aged knife surfaces to evaluate recoverable surface-associated CWD-prion seeding activity detected by RT-QuIC after prion exposure and decontamination. Our results indicate decreased recoverable prion seeding activity from knife surfaces aged with 40% bleach. We also observed some recoverable seeding activity post-decontamination on knives chemically aged with 10% bleach and Wex-Cide-128, but largely similar efficacy to prior studies. This implies that existing chemical prion decontaminants are likely effective after repeated use on steel surfaces. Full article

This study investigates potassium-L zeolite (K-L) as an adsorbent for the removal of thallium (Tl⁺) from aqueous solutions, focusing on the relationship between cation exchange and framework structural response. X-ray powder diffraction (XRPD), thermal analysis, and Rietveld refinements were employed to monitor structural modifications upon Tl⁺ uptake, combined with batch adsorption experiments to evaluate the removal performance. At low Tl⁺ uptake, only minor structural perturbations occur, mainly involving slight shifts in extra-framework cation positions and limited rearrangement of channel water molecules. At higher Tl⁺ concentrations, a measurable anisotropic expansion of the zeolite framework is observed, consistent with partial substitution of K⁺ by Tl⁺ and progressive modification of the hydration environment within the pores. Moreover, the crystallographic distribution of Tl⁺ differs from that of the original K⁺ cations, suggesting a specific site preference during the uptake process. Batch experiments reveal rapid uptake kinetics, with equilibrium reached within minutes, and high removal efficiency up to 99.5%. The adsorption behaviour is well described by the Langmuir model, with a maximum adsorption capacity of 631 mg g⁻¹. These findings highlight the coupling between ion exchange and structural flexibility in K-L zeolite and support its potential application for efficient thallium removal from contaminated water. Full article

Chromium is an environmental pollutant with high toxicity and carcinogenicity. It can induce severe oxidative stress and DNA damage after entering the human body through the food chain. As a plant growth-promoting rhizobacterium (PGPR) with both heavy metal tolerance and plant growth-promoting properties, Klebsiella variicola has considerable potential for the remediation of chromium contamination. In this study, chicory served as the experimental plant to explore the mitigating impacts of K. variicola on stress induced by hexavalent chromium (Cr(VI)) at a concentration of 400 mg/kg. The results showed that chromium severely inhibited the growth of chicory. In contrast, K. variicola significantly reduced the soil chromium content. As the chromium content decreased, the activities of soil urease, sucrase, catalase, and alkaline phosphatase were restored, increasing by 32.60–53.69%. Accordingly, the contents of total phosphorus, available phosphorus, total nitrogen, available nitrogen, soil organic carbon, and available potassium also increased by 34.71–51.81%. In addition, K. variicola reversed the decline in microbial diversity induced by chromium stress, promoted the growth of beneficial bacteria such as Acidobacteriota and Chloroflexota, and enhanced the stability of soil ecosystem functions. Ultimately, the growth inhibition of chicory caused by chromium stress was alleviated, with fresh weight, root length, maximum leaf width, maximum leaf length, plant height, and stem diameter significantly increasing by 21.89–61.60%. This study enhances our comprehension of the various functions of PGPR when exposed to heavy metal stress, and provides support for the development of microbe–plant combined strategies in the remediation of chromium-contaminated soils. Full article

Microplastics (MPs) in wastewater treatment plants are exposed to oxidative conditions during disinfection and advanced oxidation processes (AOPs), which can alter morphology and surface chemistry and influence interactions with coexisting contaminants. Here, accelerated chemical oxidation was simulated using heat-activated potassium persulfate (K₂S₂O₈) and sodium hypochlorite (NaOCl) to examine the oxidative aging of MPs made from polyethylene (PE), polyethylene terephthalate (PET), and polypropylene (PP). Changes in particle morphology and surface chemistry before and after oxidant treatment were characterized using scanning electron microscopy (SEM) for morphological analysis and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy for chemical characterization. Carbonyl formation, an indicator of polymer oxidation, was evaluated using the carbonyl index (CI). Both oxidants induced surface morphological defects and carbonyl functional groups in the MPs, with CI increasing with degradation time. The CI trends suggest that MP oxidation varies with polymer type and oxidant. The effect of oxidative aging on MP sorption capacity was also investigated using copper ions as a model inorganic constituent. Although oxidative aging introduced oxygen-containing functional groups, no statistically significant differences in copper sorption were observed between pristine and oxidized MPs, indicating that MPs can act as vectors for copper regardless of their degree of surface oxidation. Full article

Due to the increased anthropogenic load, crops are polluted with heavy metals, including nickel (Ni). This is a serious environmental problem, as Ni penetrates barrier-free into cereal crops and accumulates in the grains used by humans and animals for food. Wheat is one of the main staple crops, cultivated in many countries. This study suggested that plant growth promoting bacteria (PGPB) with varying enzymatic activities could help wheat plants to cope with Ni stress by reducing Ni toxicity and regulating the metal’s homeostasis. PGPB Bacillus megaterium AFI1 has a strong phosphate-solubilizing activity and produces siderophores, while Paenibacillus nicotianae AFI2 has nitrogen-fixing and silicate-solubilizing activities. Both strains produce indole and polysaccharides and have 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. PGPB under Ni exposure (100 mg/kg of soil) significantly increased grain yield (by 34–42%) and decreased (by 20–33%) Ni content in wheat grains. PGPB also decreased malondialdehyde (MDA) and H₂O₂ levels in wheat plants under Ni stress. The contents of iron (Fe), boron (B), nitrogen (N) and phosphorus (P) decreased significantly and potassium (K) and zinc (Zn) oppositely increased significantly in all plant organs under Ni exposure. The inoculation with AFI1 mainly increased P and Fe, and the inoculation with AFI2 increased N and silica (Si) in wheat grains under Ni stress. In our experiments, under nickel exposure PGPB Bacillus megaterium AFI1 and Paenibacillus nicotianae AFI2 increased antioxidant protection of plants by decreasing the level of stress ethylene and regulating the homeostasis of nutrients in wheat plants. These PGPB can be considered as promising candidates for the development of biologicals to be used for growing plants in soils with low levels of nickel contamination. Full article

Intensive management practices promote microplastic (MP) accumulation in Phyllostachys violascens forests, posing potential threats to ecosystem stability and the edibility safety of bamboo shoots. However, how urbanization and mulching duration jointly regulate MP distribution, transfer, and associated food safety risks remains unclear. We investigated MP dynamics across urban–rural gradients (suburban vs. exurban) under different mulching durations (no mulching, short–term mulching, and long–term mulching), focusing on the rhizome–root–soil system and bamboo shoots. MP abundance was significantly higher in suburban forests, with maxima under long–term mulching, whereas in exurban forests, peaks occurred under long–term mulching. Urbanization also altered MP allocation patterns, with enrichment in rhizome roots and rhizomes in suburban forests but greater accumulation in bamboo shoots in exurban forests. Long–term mulching markedly enhanced MP accumulation across all components, particularly in clump roots, where abundance was three times higher than that in exurban forests. MPs were predominantly small (20–50 μm), mainly composed of acrylates (ACRs), polyvinyl chloride (PVC), polypropylene (PP), polyethylene terephthalate (PET), polyurethane (PU), and polyethylene (PE). Along the “soil–root–rhizome” continuum, contrasting transfer patterns emerged between suburban and exurban forests, with soil total potassium identified as the key driver regulating MP migration and redistribution. Although the pollution load index indicated moderate contamination without significant accumulation in bamboo shoots, the ecological risk index revealed a high ecological risk, highlighting potential food safety concerns. Overall, MP accumulation and migration in Ph. violascens systems are jointly shaped by urban–rural gradients and mulching duration, with implications for belowground processes and the safety of edible bamboo shoots. Full article

Emerging contaminants (ECs) encompass a wide spectrum of pollutants, from endocrine disruptors and persistent organic pollutants to microplastics and pharmaceutical residues. These contaminants often exhibit distinct chemical and physical properties compared with traditional pollutants and potentially pose risks to human health, especially as they have become pervasive in environmental and biological systems. ECs can also pose a significant threat to cardiovascular health, as they may target the ion channels that are critical to regulating cardiac excitability and contraction. However, the impact of ECs on the cardiovascular system, particularly on cardiac ion channels, remains elusive. In this review, we aim to provide an overview of the knowledge base concerning the impact of emerging contaminants on cardiac ion channels, with an emphasis on the effects of these compounds on cardiac excitability, contractility, and overall cardiovascular function. We first outline the structural and functional characteristics of ion channels, along with how these transmembrane proteins regulate cardiac physiology. Subsequently, we detail how typical ECs directly or indirectly interact with various ion channels—including sodium, calcium, potassium channels, as well as ion transporters and exchangers. Special attention is given to studies that have demonstrated cell-level responses or examined how pollutant concentration and chemical structure affect the modulation of ion channels. This review compiles recent research reports to elucidate the mechanisms by which EC exposure disrupts cardiac ion channels, potentially leading to cardiotoxicity. Moreover, the insights gathered herein illuminate critical research gaps and outline essential directions for future investigations. Full article

This study explores the use of metallurgical slag extracts as a liquid mineral fertilizer for maize cultivation. Slag samples were obtained from the former lead smelter in Shymkent and the Zhezkent Mining and Processing Plant. Elemental analysis identified the slag from the second storage area of the Shymkent smelter as the least contaminated with potentially toxic elements and enriched in macro- and micronutrients. Slag extraction was conducted via chemical leaching using potassium sulfate and ammonia solutions in a hydrogen peroxide medium, yielding Cu²⁺ and Zn²⁺ concentrations of 423.751 mg/L and 86.649 mg/L, respectively. The resulting extracts were diluted with distilled water at a ratio of 1:10 (potassium sulfate extract) and 1:200 (ammonia extract) and applied to assess early seed development and subsequent maize yield. Seed germination rates were comparable to those of the control group (100%). After 90 days of growth, maize plants treated with the ammonia-based extract showed positive effects on root system development, stem growth, and cob formation. The concentration of potentially toxic elements in the dry plant biomass remained within permissible limits. These findings demonstrate the potential for the safe agricultural use of these extracts while ensuring the rational utilization of industrial waste. Full article

Sewage sludge (SS) is a by-product of wastewater treatment processes (WWTPs) and is rich in organic matter and essential nutrients like nitrogen, phosphorus, and potassium, making it a potential fertilizer for agricultural use. However, its application is often limited due to the presence of pathogenic bacteria, viruses, metals, and organic contaminants that can accumulate in soils and crops, raising concerns about food safety. Sewage sludge is additionally challenging to handle due to its high moisture content, low density, and odor emission. To mitigate environmental risks and enhance its usability as a soil fertilizer, SS must be stabilized. Various techniques, including chemical, physical, and biological, can be used to stabilize SS. The addition of lime and composting has received particular attention among these techniques owing to the benefits they offer. Both methods effectively control and eliminate pathogens and reduce metal bioavailability, thus improving their agricultural utility. This review emphasizes the importance of using SS for agricultural purposes, placing particular focus on the procedures of composting and liming to stabilize and enhance the quality of SS, hence promoting its safety. Full article

Soil contamination by heavy metals is a significant sustainability and ecological issue, impacting on the health of ecosystems and groundwater. This study assessed the efficacy of malic acid as a biodegradable and environmentally benign agent for the remediation of soils contaminated with cadmium, chromium, copper, and zinc. Two soils with contrasting textures were treated with a 10% malic acid solution at solid/liquid ratios of 1:5 and 1:10 for contact times of 2, 4, 6, and 8 h. The extraction efficiency varied depending on metal type, soil texture, and washing conditions. Cadmium removal ranged from 26% to 55%, zinc removal ranged from 10% to 25%, while copper showed variable extraction (5–45%) depending on initial soil concentration. Chromium exhibited the highest removal efficiency (30–90%), quantified as total chromium; however, the absence of speciation analysis (Cr(III)/Cr(VI)) represents a key limitation and may affect the interpretation of the removal performance. FTIR and UV–Vis analyses confirmed the formation of metal–carboxylate complexes and changes in soil functional groups during the washing process. In addition, significant mobilization of nitrogen and potassium was observed, whereas phosphorus remained relatively stable. The results highlight the influence of soil texture and multi-metal interactions on malic acid washing efficiency and provide a laboratory-scale environmental assessment of malic acid as a sustainable remediation alternative for soil remediation, while emphasizing the need for further evaluation regarding chromium speciation and post-treatment soil quality and sustainability impacts. Full article

Groundwater nitrate contamination, coupled with long-term overexploitation and intensive anthropogenic perturbations, has become a critical environmental challenge in the northwestern North China Plain, underscoring the urgent need to elucidate groundwater hydrochemical characteristics and their genetic mechanisms. Taking the upper section of the Yongding River alluvial–proluvial fan as the study area, this research aims to quantitatively decipher the hydrochemical characteristic and genetic mechanism of high-nitrate groundwater, identify the sources of nitrate contamination, and assess the associated human health risks. By leveraging over a decade of continuous hydrochemical monitoring data, an integrated analytical approach is adopted, including hydrochemical ionic ratio analysis, Positive Matrix Factorization, and Human Health Risk Assessment. The results indicate that the groundwater is characterized by HCO₃-Ca. The pH values range from 7.2 to 8.2 while the total dissolved solids concentrations vary between 695 mg/L and 949 mg/L. Ionic ratio analysis demonstrates that water–rock interaction is the dominant controlling process, involving silicate hydrolysis, dissolution of carbonates, gypsum dissolution, and cation exchange. The Positive Matrix Factorization model quantitatively identifies four key factors controlling the hydrochemical characteristics of groundwater. Factor 1 is dominated by NO₃⁻ (76.67%) and associated with exogenous nitrate inputs from nitrogen fertilizer application. Factor 2 is dominated by Na⁺ (72.26%) and Mg²⁺ (81.67%), deriving from silicate weathering and dolomite dissolution. Factor 3 is governed by pH (59.62%) and K⁺ (71.65%), with its driving mechanism being the weathering and dissolution of potassium-bearing silicate minerals. Factor 4 is dominated by SO₄²⁻ (50.12%) and constitutes a mixed source associated with sulfur-containing fertilizer application and livestock breeding. Groundwater NO₃⁻ concentrations range from 4.2 mg/L to 23.3 mg/L, with 69% of dry-season and 77% of wet-season samples exceeding the 10 mg/L threshold, primarily originating from manure and domestic wastewater. HHRA results show that nitrate poses significant non-carcinogenic health risks, with the highest risk observed in children (100% of samples at high risk), followed by adult females (92% at high risk) and adult males (77~92% at high risk). This study provides quantitative insights into the genetic mechanisms of groundwater nitrate contamination and offers a scientific basis for groundwater quality management and health risk mitigation in the NCP and other similar agricultural regions worldwide. Full article

Artificial sweeteners have emerged as contaminants of increasing concern due to their widespread consumption, environmental persistence, and resistance to conventional wastewater treatment. This review provides an integrated assessment of global research trends and the environmental behavior of major artificial sweeteners, including sucralose, acesulfame potassium, saccharin, and aspartame. Bibliometric analysis of SCOPUS-indexed publications reveals rapid growth in research since 2010, with key themes focusing on environmental occurrence, treatment technologies, and ecotoxicological effects. These compounds are frequently detected in wastewater effluents, surface waters, groundwater, and even drinking water systems, driven by their high solubility and limited biodegradability. Their persistence raises concerns regarding ecological impacts, including potential alterations to microbial communities and aquatic organisms. In addition, emerging evidence suggests potential human health implications, including gut microbiota disruption, metabolic effects, and risks associated with chronic low-dose exposure, although these remain poorly understood. The performance of existing treatment technologies, including biological processes, adsorption, advanced oxidation, and membrane filtration, is critically evaluated, highlighting limitations in complete removal and in the formation of transformation products. Future research should prioritize sustainable treatment strategies, comprehensive risk assessment, and improved monitoring frameworks to better address both environmental and human health risks associated with artificial sweeteners. Full article