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The brewing process of craft beer can introduce contamination by heavy metals such as Cd, Pb, and Zn from various sources. Cadmium and lead metals are particularly worrisome because of their harmful effects on human health. This study aimed to evaluate a method for quantifying the levels of Cd, Pb, and Zn in craft beer brands sold in the northern region of the Metropolitan District of Quito, Ecuador, using atomic absorption spectroscopy. For confidentiality, the brands were anonymized as Brands A to I. Standard addition curves were employed for metal quantification, with repeatability assessed via the coefficient of variation (CV%) and accuracy determined by recovery (R%). The Cd content in Brands B–G and I was below the threshold established by the Mercosur Resolution Nº 12/11. Additionally, Brands A and D–H complied with the Ecuadorian INEN 2262 standard for maximum Pb concentration in beer. All samples showed Zn levels substantially below the maximum levels permitted by Ecuadorian regulations. Brands A, B, C, and H exhibited the highest concentrations of Cd and Pb. [ABSTRACT FROM AUTHOR]

In recent years, various industrial and agricultural problems have been highlighted, and the pollution of heavy metal ions to water bodies has become a considerable serious phenomenon. Adsorption method is an efficient, low‐cost, and easy to implement method for removing heavy metal ions, which does not produce secondary pollution, and has been widely used in water treatment. Polysaccharides are natural polymers, and their hydroxyl, carboxyl, and amine groups provide feasibility for the synthesis of hydrogels with various structures. The synthesized polysaccharide hydrogel has the characteristics of high adsorption capacity, specific adsorption, nontoxic, and so on. In this review, the kinds of polysaccharide hydrogels and different synthesis methods were discussed first. Then, the adsorption mechanism and different adsorption modes of polysaccharide hydrogels were reviewed. Finally, the effects of different environmental factors on the adsorption capacity of polysaccharide hydrogel were studied. The future research on the adsorption of heavy metal ions by polysaccharide hydrogels was proposed. [ABSTRACT FROM AUTHOR]

Background: The present study aimed to assess the heavy metal concentrations in water from different sampling sites of the Halda River, the only natural breeding ground of Indian major carps. Objectives: We have analysed the contamination level and seasonal variations of heavy metals (viz. Fe, Cu, Zn, Cr, Cd and Pb). The favourability of the breeding environment was assessed by different contamination indices. Methods: Samples were collected from six sampling sites for four different seasons, and the metal concentrations were determined for water samples using Flame atomic absorption spectrophotometer. Results: The obtained order of mean concentrations of heavy metals for four seasons was winter > spring > monsoon > pre‐monsoon, and the assessed mean concentrations (mg/L) of heavy metals follow the trend: Fe (9.129) > Pb (0.033) > Zn (0.024) > Cr (0.017) > Cu (0.012) > Cd (0.002). The concentration of Fe was found above the permissible limit set by the World Health Organization (WHO) (Guidelines for Water Quality) and ECR (1997), and the concentrations for Pb were found above the USEPA (2006) limit in all four seasons. Contamination indices (heavy metal pollution Index [HPI] and metal index [MI]) indicate that during winter and monsoon, the river water metal condition is critical (HPI > 100) and the sites are moderately as well as slightly (1< MI <2) affected by the studied heavy metals. Contamination indices, such as contamination factors (Cf), degree of contamination (Cdeg) and the pollution load index (PLI), demonstrate the fact that Fe and Pb remarkably contaminated the studied sampling sites. The Pearson correlation matrix and the principal component analysis (PCA) revealed that the studied metals are connected by their sources, which can be geological or anthropogenic. Conclusion: Urgent initiatives need to be taken, and effective strategies must be implemented to control the different sources responsible for the entry of heavy metals into the Halda River water. [ABSTRACT FROM AUTHOR]

In the present study, we have designed the current experiment to explore the contribution of different sources of phosphorus (P) i.e., single super phosphate (SSP), nitrophoska (NP), and di-ammonium phosphate (DAP) at two different levels i.e., 50 and 100 mg kg−1 in mediating growth and eco-physiology by alleviating lead (Pb) stress i.e., (100 mg kg−1) in cereal crop i.e., barley (Hordeum vulgare L.). Results from the present study showed that the increasing levels of Pb in soils significantly decreased plant growth and biomass, photosynthetic pigments, gas exchange attributes, and P contents from the roots, stems, leaves and nodules. Conversely, increasing levels of Pb in the soil increased oxidative stress indicators in term of malondialdehyde, hydrogen peroxide, superoxide radicle and electrolyte leakage and enzymatic and non-enzymatic compounds and their specific gene expression and proline metabolism including proline, pyrroline-5-carboxylate, pyrroline-5-carboxylate reductase and pyrroline-5- carboxylate dehydrogenase, AsA-GSH cycle including glutathione, ascorbate, glutathione disulfide and dehydroascorbic acid, cellular fractionation including pectin methylesterase activity, uronic acid, hemicellulose I, hemicellulose II, cellulose and pectin methylesterase and also increased Pb concentration in H. vulgare. Interestingly, the application of different sources of P counteracted the toxicity of Pb in H. vulgare , leading to greater growth and biomass. This protective effect is facilitated by the P' ability to sequester reactive oxygen species, thereby reducing oxidative stress and lowering As concentrations in both the roots and shoots of the plants. Our research findings indicated that the application of different sources of P has been shown to enhance the resilience of H. vulgare to Pb toxicity, leading to not only improved biomass but also a better physiological state of the plants. [Display omitted] • Different P sources effectively mitigate Pb stress in barley. • DAP, SSP, and NP significantly enhance barley growth under Pb stress. • P application reduces Pb accumulation in barley tissues. • This study suggests innovative strategies for soil Pb remediation. [ABSTRACT FROM AUTHOR]

This research examined heavy metals distribution and potential environmental impact in seven locations along the Bhavnagar coast in Gujarat, India. The study used several analyses, including hierarchical cluster analysis (HCA), principal component analysis (PCA), and correlation analysis to investigate the harmful heavy metals present in the area. To evaluate the possible risk of Cd, Pb, Cr, Zn, Co, Cu, Ni, Mn, and Fe to the marine environment, pollution indices such as contamination factors (Cf), enrichment factor (Ef), geo-accumulation index (Igeo), ecological risk factor (Er), ecological risk index (RI) and sediment quality guidelines (SQGs) applied. Based on the results, the mean concentration of heavy metals was ranked in the following order (mg/kg): Fe (561.4) > Mn (58.9) > Cr (42) > Zn (12.5) > Pb (8.2) > Ni (7) > Cu (5.2) > Co (2.7) > Cd (.3). Compared to the pre-monsoon and post-monsoon seasons, the results showed a diluting impact on heavy metal concentrations during the monsoon season. The spatial distribution of the heavy metals indicated that the geogenic source and anthropogenic source were the primary contributors to pollution in the studied region. Principal component analysis suggests that Cd, Pb, Co and Cr may have come from shipbreaking activities, municipal discharge and industrial operations. Cf, Igeo, and Ef demonstrated no pollution to moderate pollution, with a maximum contribution of Cd, and the coastal sediment poses a minimal ecological risk for all heavy metals investigated. Shipbreaking, urban runoff, salt-marine, and agricultural runoff release toxic metals into the coastal environment. In conclusion, the information obtained from this geochemical characterization could be valuable to policymakers and stakeholders in developing effective management measures for the Bhavnagar coastal region, Gulf of Khambhat, Gujarat, India. [ABSTRACT FROM AUTHOR]

Efficient control of heavy metal pollution necessitates a comprehensive understanding of pollutant sources. In this study, we conducted a thorough investigation of 11 metals in the soil of an electronic waste (e-waste) recycling facility in South China. The sources of these metals were determined through a combination of statistical analysis and the UNMIX model. Despite government intervention, our findings reveal significant pollution of nickel, copper, zinc, cadmium, and lead in the study area. Primary contributors to heavy metal contamination in the soil were identified as demolition activities, transport emissions, and atmospheric deposition. Utilizing a source risk assessment model, we observed that children face higher noncarcinogenic and carcinogenic risks compared to adults. Remarkably, the total hazard index of the study area was found to be considerably lower than that of other e-waste dismantling cities. Moreover, the total carcinogenic risk was noted to be one order of magnitude lower than both other e-waste dismantling cities and industrial and mining cities. While acknowledging the government's commendable achievements in the standardized management of e-waste dismantling activities, our study underscores the need for targeted measures to further reduce pollution and safeguard the health of residents. These results emphasize the importance of ongoing efforts to enhance environmental protection strategies and underscore the significance of tailored interventions for sustainable pollution control in e-waste recycling facilities. [ABSTRACT FROM AUTHOR]

Water resources, particularly rivers, are increasingly exposed to pollutants, especially heavy metals of chemical origin, which are difficult to monitor and can pose risks to both ecosystems and human health. This study assesses heavy metal contamination in the Oued Fez River, focusing on the bioaccumulation by the invasive plant Pistia stratiotes. The methodology involves measuring and comparing metal concentrations in water and plant tissues. Results revealed that while aluminium (Al) slightly exceeded recommended levels at 0.2978 mg L−1, other metals like zinc (Zn), iron (Fe), copper (Cu), lead (Pb) and cadmium (Cd) remained within acceptable limits. The study demonstrates P. stratiotes' effectiveness in heavy metal phytoremediation, with its roots showing high bioaccumulation up to 19,726 mg kg−1 for Fe and 15,128 mg kg−1 for Al, indicating its potential for water decontamination. Eco-toxicological assessments, including bioconcentration and translocation factors, confirm the plant's capacity to mobilize toxic metals. Statistical analysis also points to possible industrial, urban, or agricultural contamination sources based on correlations between Al, Fe and Zn. The study underscores P. stratiotes' role in phytoremediation while emphasizing the need for monitoring and controlling contamination sources and managing the spread of this invasive species to ensure sustainable water resources. [ABSTRACT FROM AUTHOR]

Heavy metal-contaminated soil has a great impact on yield reduction of vegetable crops and soil microbial community destruction. Biochar-derived waste biomass is one of the most commonly applied soil conditioners in heavy metal-contaminated soil. Different heavy metal-contaminated soil added with suitable biochars represent an intriguing way of the safe production of crops. This study investigated the effects of two types of biochar [rice husk biochar (RHB) and sugarcane bagasse biochar (SBB)] on Cd and Pb accumulation in Shanghaiqing (SHQ, a variety of Brassica campestris L.) and Fengyou 737 (FY, a variety of Brassica napus), as well as on the soil microbial community, through a field experiment. RHB and SBB were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and Brunauer–Emmet–Teller method. The results showed that RHB and SBB displayed the higher pH, cation exchange capacity and pore properties, and the addition of RHB and SBB enhanced soil pH and rhizosphere microorganisms promoting vegetables yield. RHB treatments were more effective than SBB in reducing upward transfer of Cd and Pb, blocking the accumulation of Cd and Pb in the edible parts of SHQ and FY, and decreasing soil Cd and Pb bioavailability. Additionally, RHB and SBB changed the composition of the rhizosphere soil microbial community. The application of biochar promoted the growth of ecologically beneficial bacteria (Nitrospira, Opitutus, and Gemmatimonas) and fungi (Mortierella and Holtermanniella), whereas reducing the enrichment of plant pathogenic fungi (Alternaria, Stagonosporopsis, Lectera, and Periconia) in rhizosphere soil. Our findings demonstrated that the application of RHB significantly reduces Cd and Pb accumulation in the edible parts by decreasing the soil Cd and Pb bioavailability and altering the rhizosphere microbial community composition in two Brassica vegetables grown on Cd/Pb-contaminated soils. Thus, the application of two biochar, especially RHB is a feasible strategy for the safe production of vegetable crops in Cd/Pb co-contaminated soils. [ABSTRACT FROM AUTHOR]

Contemporary issues of ground contamination, exacerbated by elevated heavy metal levels due to industrial activities and improper waste disposal, significantly impact soil properties, the biosphere, and result in various geotechnical problems. This study delves into the efficacy of Chrysopogon zizanioides (vetiver) root micro powder (VRMP) in immobilizing Lead (Pb), Cadmium (Cd), and Chromium (Cr) within contaminated soil to prevent groundwater pollution and bioavailability. Leaching experiments were conducted to evaluate the individual immobilization of heavy metals and determine the optimal VRMP dosage, testing four dosages (0%, 1%, 5%, and 10%) for their effectiveness in immobilizing Pb, Cd, and Cr in contaminated soil. The findings suggest that addition of VRMP led to an increase in pH, facilitating the enhanced immobilization of Pb, Cd, and Cr from the contaminated soil due to the reduction in mobility of these metals. Soil treated with 10% VRMP exhibited exceptional immobilization efficiency, achieving over 90% removal across all treatments. However, agglomeration caused the leaching process to take slightly longer. Consequently, a 5% VRMP dosage is considered optimal. In conclusion, vetiver root micro powder promotes a sustainable approach to immobilize Pb, Cd, and Cr in contaminated soils, underscoring the effectiveness of eco-friendly methodologies. [ABSTRACT FROM AUTHOR]

Simple Summary: Age and size variation in widespread amphibians are often related to latitudinal or altitudinal temperature gradients. Species with toxic skin secretions, such as the fire salamander Salamandra salamandra, are an exception to the rule because their survival rates are relatively unaffected by predation, the major source of amphibian mortality. In contrast, average adult size varies greatly among populations, but variation is unrelated to geographical gradients. This study on four neighboring fire salamander populations inhabiting the catchments of low-order streams in the upper middle Rhine Valley (Koblenz, Germany) focuses on the identification of local environmental drivers of variation in age and body size distributions. I collected 192 individuals at two localities per stream, snout–vent length measured, clipped a toe for posterior skeletochronological age determination, and released salamanders in situ again. As expected, demographic parameters were in the range of other populations with an age at maturity of 2–3 years and a maximum lifespan of 17 years, but terrestrial habitat quality accounted for 3.6% of variation among populations. Variation in adult size resulted mainly from a carry-over effect of heavy metal contamination on juvenile growth rates. In conclusion, the average adult body size is a sensitive indicator of local habitat quality. Conspecific amphibian populations may vary widely in local demography and average body size throughout their geographical range. The environmental drivers of variation may reflect geographical gradients or local habitat quality. Among fire salamander populations (Salamandra salamandra), local demography shows a limited range of variation because high concentrations of skin toxins reduce mortality from predation to a minimum, whereas average adult body size varies significantly over a wide range. This study on four neighboring populations inhabiting the catchments of low-order streams in the upper middle Rhine Valley (Koblenz, Germany) focuses on the identification of local environmental drivers of variation in age and body size. I collected 192 individuals at two localities per stream, measured snout–vent length, clipped a toe for posterior skeletochronological age determination, and released salamanders in situ again. Populations were similar in age distribution. Local habitat quality accounted for a significant proportion of demographic variability, mediated by the impact of landscape-induced mortality risk, including roads and agriculture. Still, the main effect of variation in habitat quality was on adult body size, the result of growth rates of aquatic larvae and terrestrial juveniles. Larvae exposed to non-lethal heavy metal contamination in streams developed into smaller juveniles and adults than clean-water larvae, providing evidence for carry-over effects from one stage to another. The generally small average adult size in the Rhine Valley populations compared to those in other parts of the distribution range indicates the action of a still unidentified environmental driver. [ABSTRACT FROM AUTHOR]

This study investigates the presence of potentially toxic elements (PTEs) in lettuce (Lactuca sativa L.) grown in urban gardens in a highly industrialized city in Brazil and evaluates the effectiveness of different washing methods in reducing contamination. Ten elements (arsenic (As), barium (Ba), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), vanadium (V), and zinc (Zn)) were analyzed for their concentration, and a health risk assessment was performed. The results showed that Pb concentrations in lettuce from gardens near the Capuava Petrochemical Complex reached 0.77 mg kg−1, exceeding both national and international safety limits. The most effective washing procedure involved the use of sodium hypochlorite, which reduced As by 46%, Pb by 48%, and V by 52%. However, elements such as Ba, Cd, Cr, and Ni showed limited reductions of less than 10% across all washing methods. Health risk assessments revealed a particular concern for children, with the total cancer risk (TCR) exceeding acceptable limits in some gardens. Isotopic analysis of Pb revealed that atmospheric pollution from gasoline emissions and industrial activities were the primary sources of contamination. The elevated levels of Pb, Cr, and As highlight the need for targeted health education in local communities, especially regarding the importance of proper washing techniques. Risk management strategies, including improved contamination control and public awareness, are crucial to minimize exposure to these harmful elements, particularly in vulnerable populations like children. [ABSTRACT FROM AUTHOR]

Environmental pollution, driven by expanding industrial activities, is one of the most pressing issues today. Many fungi possess resistance mechanisms against heavy metals (HM), making them a sustainable approach for remediation processes. This study focuses on assessing HM concentrations in root samples taken from Pinus brutia in the Samsun Organized Industrial Zone (OIZ), a region heavily affected by environmental pollutants, and a nearby forested area (Adalar), while also examining the fungal diversity in the root endosphere. The fungal microbiota of the samples was determined using next-generation sequencing technology. Genera such as Aspergillus, Alternaria, Fusarium, Cladosporium, Trichoderma, Thelebolus, Plectosphaerella, Halokirschsteiniothelia, Exophiala, and Xenopolyscytalum were detected in the roots of P. brutia plants grown in the OIZ area, which is contaminated with HMs. The results indicate that higher levels of HM contamination may lead to changes in fungal diversity and an increase in the ratios of resistant taxa. This study aims to contribute to bioremediation strategies for HMs by elucidating the relationships between environmental pollutants and fungal microbiota. This research represents the first metagenomic analysis conducted in Samsun, Türkiye, to determine the impact of HMs on root fungal microbiota. [ABSTRACT FROM AUTHOR]

Heavy metal contamination of soil has become one of the most important environmental problems worldwide. Heavy metals can affect growth and lead to changes in microbial community composition, which could influence the growth of crops in the soil. In this study, we conducted an experiment to investigate the distribution profile of heavy metals and bacterial communities in soil with the effects of slag and/or water on the top of the soil. Extra heavy metals, acting as selective pressure, led to the loss of sensitive taxa, with tolerant or less sensitive taxa being more abundant in the community. The results showed that the addition of slag on the top of soils did not change the diversity of bacteria but influenced the relative abundance of indigenous members in the community. Water addition, however, improved the homogeneity of the environment vertically in the soil, which consequently led to a lower variation in the bacterial community. This study mimicked the scenario of tailings and abandoned mines in nature, and aimed to study the effects of mines on the soil microbial community with the influence of precipitation on the distribution of heavy metals in the soil. With the effect of precipitation, the transportation of heavy metals in the slag may influence the local bacterial community and subsequently undermine the quality of soil for agriculture. These observations provide evidence of the effects of heavy metals on the soil around abandoned mines without any treatment. Mining causes both heavy metal and water pollution, which may lead to the accumulation of heavy metals in plants and agricultural production. Therefore, it is necessary to take care of tailings with proper procedures instead of exposing them to nature. [ABSTRACT FROM AUTHOR]

Abstract Contamination of water resources by heavy metals causes health problems for humans. This study attempts to investigate the heavy metal contamination levels, health risks and sources of appraisal of groundwater and surface water in the mountain-bounded catchment and low-grade basement rock-dominated area of ​​the Irob, Tigray. Eighteen grab water samples (13 borehole water, 2 spring water and 3 surface water) were collected and analyzed for pH, electrical conductivity, total dissolved solids and heavy metals using standard procedures. The findings were contrasted with those of the standards set by the World Health Organization and the United States Environmental Protection Agency. Integrated techniques, including indexed and statistical methods, were used to determine the contamination levels of metals, risks to human health and sources. The result shows that the pH value, electrical conductivity and total dissolved solids fluctuated between 7.4 and 7.9, 516 and 2410 µs/cm and 396.7 mg/l and 1719 mg/l, respectively. The findings indicate that 94.4% of the water samples had levels of contamination above the critical limit for all three indices: the heavy metal evaluation index (HEI), the degree of contamination (cd) and the heavy metal pollution index. The hazard index of metals for adults and children was greater than 1. 88.9% of the water samples showed a cancer risk value above the recommended value (CR > 1 × 10–4) for Cd and Cr for both adults and children. Multivariate statistical analyses indicate that weathering of bedrocks and partly anthropogenic influences are responsible for the metal contamination. The study concludes that some water samples sources are unfit for human consumption that can pose health risks over time. Therefore, it is recommended to treat contaminated water sources to protect and sustain public health.

Background: Mining activities can produce large amounts of heavy metals that are discharged uncontrollably, causing widespread ecosystem pollution. Heavy metal pollution is a serious problem, as heavy metals are toxic and non-degradable, polluting air, water and soil. Although some heavy metals are considered essential for normal physiological functions, concentrations that exceed the prescribed limits can have negative impacts on human health and biota. Exposure to heavy metals can cause toxicity to various tissues, organs and systems such as circulatory, respiratory, endocrine, immune, nervous, urinary and reproductive systems. Due to the differences in toxicity of heavy metals, risk assessment is very important in environmental management. Objective: To describe the probabilistic simulation and sensitivity of health risks due to Nickel and Cobalt deposition around the mine using monte carlo simulation. Methods: The method used in this study was literature review. Data collection was done through searching online databases such as: Pubmed and Science Direct. The keywords used in the article search were "Heavy Metal Toxicity", "Heavy Metal Effects", "Heavy metal risk analysis" and "Monte Carlo Simulation". Inclusion criteria were quantitative or qualitative research, target population was heavy metals Nickel and Cobalt, published in the last 10 years (2013-2023) articles in English and articles in original, fulltext and open access. Exclusion criteria are articles that are not relevant to the topic of discussion. Results: 14 articles were found, of which 3 articles on diseases or health problems caused by nickel, 3 articles on nickel risk analysis, 5 articles on diseases or health problems caused by cobalt, 3 articles on cobalt risk analysis. Conclusion: The environment around the mine shows a high level of toxicity, caused by the presence of heavy metals. This can result in serious environmental pollution and pose a great threat to human health. Chronic exposure to heavy metals can cause various health problems, such as mutagenesis, carcinogenesis, teratogenesis, deformation and organ damage. [ABSTRACT FROM AUTHOR]

Background: Leafy greens, particularly romaine lettuce, are often associated with outbreaks due to their susceptibility to contamination from various environmental sources. This study aimed to evaluate the presence of E. coli, Salmonella, copper, nickel, zinc, and manganese in irrigation water, lettuce leaves, and agricultural soil in the Litani River Basin (LRB), Lebanon. Method: Samples were collected from five demonstration plots employing different agricultural practices. Heavy metal concentrations were determined using atomic absorption spectrometry, while E. coli and Salmonella testing were conducted through conventional culturing techniques. The impact of E. coli contamination on seed germination and the interaction effects between E. coli and heavy metals were also examined. The study also compared the effectiveness of various irrigation systems in reducing bacterial contamination. Results: The results demonstrated that contamination levels varied significantly across the plots and irrigation types. This variation underscores the necessity of site-specific mitigation strategies to enhance food safety. Our findings highlight the importance of selecting appropriate irrigation methods and implementing tailored agricultural practices to minimize the risk of contamination. Conclusion: This research provides valuable insights for optimizing agricultural practices in the LRB to ensure food safety and environmental sustainability. [ABSTRACT FROM AUTHOR]

Globally, there is growing concern over the environmental contamination of coastal ecosystems caused by anthropogenic activities. Here,we performed a study to evaluate the degree of heavy metal contamination in 5 different sediment samples collected from five sites along the Southeastern coast of India. Additionally, the research aims to explore the potential ecological implications of heavy metal contamination on the bacterial diversity, a crucial factor in upholding a sustainable ecosystem. A total of seven heavy metals, i.e., chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As), were assessed and quantified using inductively coupled plasma mass spectrometry. Targeted amplicon sequencing revealed that phylum Proteobacteria (36.9%) was the most dominating followed by Halobacterota (25.5%), Actinobacteriota (15%), Firmicutes (6.7%), Bacteroidota (4.0%), Thermoplasmatota (2.3%), Acidobacteriota (2.0%), Chloroflexi (1.6%), Planctomycetota (1.2%) and Crenarchaeota (1.1%). According to the alpha diversity estimate, lesser bacterial diversity was observed in areas with high pollution levels. Moreover, the physicochemical parameters of the sediments were analyzed. The contamination levels of the sediments were evaluated using the geo-accumulation index (Igeo), contamination factor (CF) and pollution loading index (PLI) to ascertain the comprehensive toxicity status of the sediments. The Igeo values revealed sediment pollution with metals such as Hg and Cd. The sediments obtained from the sampling site PU-01 showed the highest concentration of Hg pollution. Considering the ecotoxicological aspect, the estimated risk index (RI) values indicated a range from low to significant ecological risk. [ABSTRACT FROM AUTHOR]

The increasing proximity of the Dudumbia dumpsite, an open dumpsite in Navrongo, Ghana, to human settlements necessitates an investigation of the soil quality to safeguard the environment from heavy metal toxicity. This study examined the impact of waste dumping activities on the physicochemical properties of the soil, as well as the level of heavy metal (Pb, Cd, Ni, Cr, As, Hg, Cu, Mn, and Zn) contamination and associated risks. Various contamination and risk assessment tools were used, including the geoaccumulation index (Igeo), pollution load index (PLI), potential ecological risk (Er), and potential ecological risk index (PERI). The study found significant improvements in notable soil attributes such as phosphorus (P), organic carbon (C), total nitrogen (N), calcium (Ca), magnesium (Mg), potassium (K), sodium (Na), and effective cation exchange capacity, with percentage increases ranging from 50.8 to 2078.3%. Igeo values ranged from 2.07 to 6.20, indicating contamination levels from moderate to extreme. The PLI and PERI values were 16.241 and 1810, respectively. The Er values for the heavy metals ranged from 36 to 607, indicating ecological risk levels from low to very high, with Cd and Hg posing very high risks. These results suggest that while the dumpsite soil shows improvements in some characteristics favourable for plant cultivation, waste dumping significantly contributes to heavy metal contamination. The soil at the dumpsite is deteriorated and poses significant health risks, particularly due to Cd and Hg. Therefore, remediation efforts should prioritise mitigating the risks posed by Cd and Hg. [ABSTRACT FROM AUTHOR]

Contamination of water resources by heavy metals causes health problems for humans. This study attempts to investigate the heavy metal contamination levels, health risks and sources of appraisal of groundwater and surface water in the mountain-bounded catchment and low-grade basement rock-dominated area of ​​the Irob, Tigray. Eighteen grab water samples (13 borehole water, 2 spring water and 3 surface water) were collected and analyzed for pH, electrical conductivity, total dissolved solids and heavy metals using standard procedures. The findings were contrasted with those of the standards set by the World Health Organization and the United States Environmental Protection Agency. Integrated techniques, including indexed and statistical methods, were used to determine the contamination levels of metals, risks to human health and sources. The result shows that the pH value, electrical conductivity and total dissolved solids fluctuated between 7.4 and 7.9, 516 and 2410 µs/cm and 396.7 mg/l and 1719 mg/l, respectively. The findings indicate that 94.4% of the water samples had levels of contamination above the critical limit for all three indices: the heavy metal evaluation index (HEI), the degree of contamination (cd) and the heavy metal pollution index. The hazard index of metals for adults and children was greater than 1. 88.9% of the water samples showed a cancer risk value above the recommended value (CR > 1 × 10–4) for Cd and Cr for both adults and children. Multivariate statistical analyses indicate that weathering of bedrocks and partly anthropogenic influences are responsible for the metal contamination. The study concludes that some water samples sources are unfit for human consumption that can pose health risks over time. Therefore, it is recommended to treat contaminated water sources to protect and sustain public health. [ABSTRACT FROM AUTHOR]

The utilization of treated wastewater (TWW) for agricultural irrigation can enhance soil properties and fertility for better crop growth. However, toxic chemicals in TWW, if exceeding permissible limits, pose environmental and health risks. This study aims to evaluate the quality of treated wastewater (TWW) and groundwater used for irrigation in alfalfa and date palm fields, focusing on specific ion toxicity, salinity, heavy metal concentrations, and other water quality parameters. Water samples were collected from four plantation sites in the Ibra and Alqabil provinces during the summer and winter seasons of 2020 and 2021. The samples were analyzed for electrical conductivity (EC), pH, total dissolved solids (TDS), carbonate, bicarbonate, and the presence of arsenic (As), cadmium (Cd), cobalt (Co), boron (B), lead (Pb), nickel (Ni), copper (Cu), iron (Fe), zinc (Zn), manganese (Mn), and chromium (Cr). The findings reveal that both TWW and groundwater in the sampled sites exhibited salinity levels detrimental to sensitive crops. Trace element concentrations generally adhered to permissible limits as defined by FAO and Oman standards, except for boron, which exceeded allowable limits by up to 40% in groundwater when compared to the control site. Notably, cobalt (Co), arsenic (As), and cadmium (Cd) were undetectable in all water samples. Additionally, groundwater samples taken in close proximity to sewage treatment plants (STPs) displayed a 37% increase in EC, TDS, and heavy metal concentrations. This suggests that groundwater, like TWW, may contain undesirable salts and heavy metals that could compromise water quality. This research underscores the importance of monitoring and assessing the quality of both treated wastewater and groundwater used for irrigation. While these water sources hold potential benefits for agriculture, they also carry the risk of negatively impacting soil and crop health due to salinity and the presence of certain contaminants. This study provides critical insights into the safe use of TWW and groundwater in agricultural practices, highlighting areas for improvement in water treatment and management strategies to ensure sustainable agricultural productivity. [ABSTRACT FROM AUTHOR]

This study evaluates the impact of multi-year protection of grapevines using copper-based pesticides on heavy metal content in soil, leaves, and fruit under organic and conventional cultivation methods. Conducted on Solaris, Hibernal, and Muscaris grapevine varieties in north-western Poland, the research highlights significant differences between the two cultivation approaches. In organic vineyards, copper content in soil averaged 10.25 mg/kg, significantly higher than the 9.05 mg/kg found in conventional soils. Manganese levels were also elevated in organic soils (223 mg/kg) compared to conventional ones (299 mg/kg). Conversely, conventional vineyards exhibited higher zinc and lead concentrations, averaging 47.10 mg/kg and 20.34 mg/kg, respectively, versus 43.50 mg/kg and 11.22 mg/kg in organic soils. The organic soils also had higher salinity (46.50 mg/kg) than conventional ones (30.50 mg/kg). The fruits of grapevines in organic cultivation showed higher copper and zinc levels, with the Solaris variety containing 15.01 mg/kg of copper and the Muscaris variety having 11.43 mg/kg of zinc. These levels exceed the commonly encountered ranges of <1 to 10 mg/kg. Lead content in fruits was higher in organic cultivation (2.19 mg/kg) than in conventional cultivation (1.18 mg/kg), occasionally surpassing the critical value for consumable plants (1 mg/kg). Leaves of grapevines from organic vineyards had significantly higher copper and manganese content than those from conventional vineyards, with the Hibernal variety showing the highest levels. These findings underscore the necessity for monitoring and managing heavy metal content in vineyard soils to ensure fruit quality and safety. [ABSTRACT FROM AUTHOR]

Maize is a crucial staple crop that ensures global food security by supplying essential nutrients. However, heavy metal (HM) contamination inhibits maize growth, reduces output, and affects food security. Some endophytic fungi (EFs) in maize seeds have the potential to enhance growth and increase dry biomass, offering a solution to mitigate the negative effect of HM contamination. Using these functional EFs could help maintain crop production and ensure food safety in HM-contaminated areas. In the present study, the diversity of EFs in corn grains from various HM-contaminated areas in China was studied through culture-dependent and culture-independent methods. We tested the plant growth-promoting (PGP) traits of several dominant culturable isolates and evaluated the growth-promoting effects of these twenty-one isolates through pot experiments. Both studies showed that HM contamination increased the diversity and richness of corn grain EFs and affected the most dominant endophytes. Nigrospora and Fusarium were the most prevalent culturable endophytes in HM-contaminated areas. Conversely, Cladosporium spp. were the most isolated endophytes in non-contaminated areas. Different from this, Saccharomycopsis and Fusarium were the dominant EFs in HM-contaminated sites, while Neofusicoccum and Sarocladium were dominant in non-contaminated sites, according to a culture-independent analysis. PGP trait tests indicated that 70% of the tested isolates (forty-two) exhibited phosphorus solubilization, IAA production, or siderophore production activity. Specifically, 90% of the tested isolates from HM-contaminated sites showed better PGP results than 45% of the isolates from non-contaminated sites. The benefit of the twenty-one isolates on host plant growth was further studied through pot experiments, which showed that all the isolates could improve host plant growth. Among them, strains derived from HM-contaminated sites, including AK18 (Nigrospora), AK32 (Beauveria), SD93 (Gibberellia), and SD64 (Fusarium), had notable effects on enhancing the dry biomass of shoots and roots of maize under Cd stress. We speculate that the higher ratio of PGP EFs in corn grains from HM-contaminated areas may explain their competitiveness in such extreme environments. Fusarium and Cladosporium isolates show high PGP properties, but they can also be phytopathogenic. Therefore, it is essential to evaluate their pathogenic properties and safety for crops before considering their practical use in agriculture. [ABSTRACT FROM AUTHOR]

The heavy metal toxicity of marketed Ayurvedic herbal formulations has been sporadically reported in the literature. Drakshadi (DK) and Gandharvahastadi (GK) decoctions are widely prescribed classical Ayurvedic herbal formulations. The potential adverse heavy metal toxicity due to consequent intake of DK and GK have been published in scientific papers or reported through pharmacovigilance. The objective of our investigation was to determine the presence of heavy metals in marketed DK and GK, with reference to the Ayurveda Pharmacopeia of India (API) standards. In this study, the concentration of four heavy metals, Arsenic (As), Cadmium (Cd), Lead (Pb), and Mercury (Hg) were investigated using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). These metals are not known to have any role in the pharmacological activity of these formulations. However, their presence beyond acceptable limits can have harmful consequences. Eighteen random samples each of DK and GK decoctions were collected from different pharmacy outlets, Kerala province, India. We tested 36 market samples of the above formulations for heavy metals, which were found to be within the limits prescribed by the Ayurvedic Pharmacopoeia of India. Our study suggests that heavy metal contamination of Ayurvedic formulations may not be widespread as suspected. However, continuous dynamic monitoring of Ayurvedic herbal formulations for heavy metal contamination is warranted considering the possibility of inadvertent contamination of raw drugs from environmental exposure. [ABSTRACT FROM AUTHOR]

Groundwater resources in Bitlis province and its surroundings in Türkiye's Eastern Anatolia Region are pivotal for drinking water, yet they face a significant threat from fluoride contamination, compounded by the region's volcanic rock structure. To address this concern, fluoride levels were meticulously measured at 30 points in June 2019 dry period and September 2019 rainy period. Despite the accuracy of present measurement techniques, their time-consuming nature renders them economically unviable. Therefore, this study aims to assess the distribution of probable geogenic contamination of groundwater and develop a robust prediction model by analyzing the relationship between predictive variables and target contaminants. In this pursuit, various machine learning techniques and regression models, including Linear Regression, Random Forest, Decision Tree, K-Neighbors, and XGBoost, as well as deep learning models such as ANN, DNN, CNN, and LSTM, were employed. Elements such as aluminum (Al), boron (B), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), phosphorus (Pb), lead (Pb), and zinc (Zn) were utilized as features to predict fluoride levels. The SelectKbest feature selection method was used to improve the accuracy of the prediction model. This method identifies important features in the dataset for different values of k and increases model efficiency. The models were able to produce more accurate predictions by selecting the most important variables. The findings highlight the superior performance of the XGBoost regressor and CNN in predicting groundwater quality, with XGBoost consistently outperforming other models, exhibiting the lowest values for evaluation metrics like mean squared error (MSE), mean absolute error (MAE), and root mean squared error (RMSE) across different k values. For instance, when considering all features, XGBoost attained an MSE of 0.07, an MAE of 0.22, an RMSE of 0.27, a MAPE of 9.25%, and an NSE of 0.75. Conversely, the Decision Tree regressor consistently displayed inferior performance, with its maximum MSE reaching 0.11 (k = 5) and maximum RMSE of 0.33 (k = 5). Furthermore, feature selection analysis revealed the consistent significance of boron (B) and cadmium (Cd) across all datasets, underscoring their pivotal roles in groundwater contamination. Notably, in the machine learning framework evaluation, the XGBoost regressor excelled in modeling both the "all" and "rainy season" datasets, while the convolutional neural network (CNN) outperformed in the "dry season" dataset. This study emphasizes the potential of XGBoost regressor and CNN for accurate groundwater quality prediction and recommends their utilization, while acknowledging the limitations of the Decision Tree Regressor. [ABSTRACT FROM AUTHOR]

The evaluation and monitoring of sites contaminated with heavy metals are essential for pollution remediation and prevention. In this study, we conducted geophysical and geochemical investigations at a site exhibiting heavy metal contamination downstream from an abandoned mine, with the aim of analyzing the extent of contamination and its temporal variation. We employed geophysical survey methods including electrical resistivity and induced polarization surveys of areas contaminated with heavy metals. Repeated surveys were conducted over time using the electrical resistivity method. Numerical simulations were employed to mitigate and eliminate electrical noise stemming from topography on the site. Additionally, time-lapse inversion was conducted on the resistivity data sets to analyze the changes in resistivity caused by variations in heavy metal contaminants. In the geochemical survey, soil samples were collected from the same locations as the geophysical survey, and chemical properties including pH, water content, electrical conductivity, and cation exchange capacity were analyzed. Our results showed that with the reduction of major sources of As and Zn contamination by 50%, the time-lapse electrical resistivity inversion results indicated that the resistivity of the subsurface materials increased by a factor of two. This paper demonstrated the natural reduction of the heavy metal contaminants at the site due to rainfall, aiming to comprehensively analyze the resultant alteration of both geochemical and geophysical properties. [ABSTRACT FROM AUTHOR]

Zostera japonica, as one of the major seagrasses in the Yellow River Estuary, plays a critical ecological role, particularly in providing habitat for marine organisms, stabilizing sediment, and contributing significantly to carbon sequestration. In recent years, Zostera japonica seagrass beds have receded extensively due to multiple impacts of natural factors and human activities. This study investigates the complex effects of extreme climate events and human activities on the growth mechanisms of Zostera japonica in the Yellow River Estuary using a combination of field sampling, laboratory analysis, and quantitative calculations. The result shows that there are significant differences in sediment characteristics between the north and south shores, with the south shore having finer sediments and higher nutrient content, which support more robust seagrass growth. The Water and Sediment Regulation Scheme (WSRS) dramatically alters water quality by reducing salinity and increasing turbidity, thus inhibiting photosynthesis and disrupting the physiological functions of Zostera japonica. Additionally, WSRS introduces an increase in heavy metals, which could potentially impact plant health and stress levels. Extreme weather events, particularly Super Typhoon Lekima, further compound these impacts by causing soil erosion, uprooting seagrass beds, and reducing biomass and seed production. The interplay of WSRS, climate change, and anthropogenic activities necessitates integrated management strategies to mitigate adverse effects and enhance habitat resilience. This study underscores the need for specific management strategies, such as controlling heavy metal inflows, implementing sediment stabilization techniques, and regulating freshwater discharge during key growth periods, to mitigate adverse effects and enhance habitat resilience for Zostera japonica in the Yellow River Estuary.

ABSTRACT Background The present study aimed to assess the heavy metal concentrations in water from different sampling sites of the Halda River, the only natural breeding ground of Indian major carps. Objectives We have analysed the contamination level and seasonal variations of heavy metals (viz. Fe, Cu, Zn, Cr, Cd and Pb). The favourability of the breeding environment was assessed by different contamination indices. Methods Samples were collected from six sampling sites for four different seasons, and the metal concentrations were determined for water samples using Flame atomic absorption spectrophotometer. Results The obtained order of mean concentrations of heavy metals for four seasons was winter > spring > monsoon > pre‐monsoon, and the assessed mean concentrations (mg/L) of heavy metals follow the trend: Fe (9.129) > Pb (0.033) > Zn (0.024) > Cr (0.017) > Cu (0.012) > Cd (0.002). The concentration of Fe was found above the permissible limit set by the World Health Organization (WHO) (Guidelines for Water Quality) and ECR (1997), and the concentrations for Pb were found above the USEPA (2006) limit in all four seasons. Contamination indices (heavy metal pollution Index [HPI] and metal index [MI]) indicate that during winter and monsoon, the river water metal condition is critical (HPI > 100) and the sites are moderately as well as slightly (1

This study aims to investigate the effect of the combined method of freeze–thaw and leaching on the removal of cadmium (Cd) in soil and to provide a theoretical basis for the remediation of farmland soil polluted by heavy metals. The removal process and mechanism of Cd were deduced through oscillatory leaching experiments and freeze–thaw leaching simulation experiments, and the influence of the freeze–thaw leaching technology on the soil environment was evaluated. The results of oscillatory leaching showed that a mixture consisting of 0.80 mol/L citric acid and 0.80 mol/L ferric chloride in a 1:19 vol ratio effectively remove 47.75 % of Cd, indicating that the composite leaching agent could effectively remove Cd from the soil. The results of the freeze–thaw leaching simulation experiment showed that although the freeze–thaw leaching treatment increased the total Cd content in the 0–5 cm soil layer, the total Cd content in the 5–10 cm, 10–15 cm, and 15–20 cm soil layers decreased by 5.08 %, 2.39 %, and 5.68 %, respectively. The freeze–thaw leaching increased the content of exchangeable Cd (p

Heavy metal pollutants can be effectively removed from soil through phytoremediation using root exudates. Herein, experiments were conducted to assess the phytoremediation capabilities of Rumex acetosa L. and Rumex K-1 root exudates for copper (Cu) and lead (Pb) contamination. Results indicated that these root exudates effectively adsorbed Cu and Pb. Furthermore, the optimal adsorption conditions of Cu by the root exudates of both plants were as follows: light duration of 36 h, light intensity of 8000 Lx, temperature of 25 °C and CO(NH2)2 concentration of 0 %. Moreover, the optimal adsorption conditions of Pb by Rumex acetosa L. and Rumex K-1 root exudates were light duration of 48 h and 24 h, respectively, light intensity of 8000 Lx, temperature of 25 °C and CO(NH2)2 concentration of 0 %. In addition, the root exudates from both plants enhanced the enrichment and transport of Cu and Pb. Moreover, the root was found to be the main accumulation site of Pb, while the stems and leaves were the main accumulation sites of Cu. With the application of root exudates, plant growth increased, with growth indices in Rumex acetosa L. and Rumex K-1 groups treated with exudates being 1.08–1.81-fold and 1.06–1.9-fold higher, respectively, compared with the untreated ones; physiological indexes showed 1.14–2.62-fold and 1.14–2.71-fold improvements, respectively. Remediation efficiency indexes showed 1.05–1.62-fold and 1.10–1.89-fold improvements, respectively. Rumex acetosa L. and Rumex K-1 exhibited promising potential for the phytoremediation of Cu and Pb, with root exudates playing a critical role in metal adsorption and stabilisation, suggesting their potential for enhancing remediation capabilities. This study sheds light on the mechanisms of root exudate–assisted phytoremediation and provides insights into alleviating heavy metal pollution.

The Beck mine, located in the Republic of Karelia, Russia, is an abandoned mining site with significant potential for environmental contamination due to the presence of potential pollutants in its waste rocks. In this study, we investigated the chemical composition of mine waters and waste rocks and developed a theoretical model to understand waterrock interactions and the release of potential pollutants. Water samples collected from various locations on the Beck mine property were analyzed for chemical composition and showed low concentrations of total dissolved solids with pH values ranging from 6.42 to 7.74. The chemical composition of natural waters was determined by ICP-MS, ICP-AES, ion chromatography, potentiometric titration, and spectrophotometry. Equilibrium kinetic modeling was used to simulate water-rock interactions. The model predicted the concentrations of major and trace elements, demonstrating that dissolution-precipitation and complexation are the primary mechanisms shaping the chemical composition of mine waters. The dynamics of dissolution-precipitation of Fe-containing minerals highlighted the importance of the duration of water-rock interaction, with stagnant mine waters exhibiting higher concentrations of heavy metals. In addition, the presence of dissolved organic matter played a critical role in the accumulation of iron and arsenic in the studied mine waters. Overall, this study highlights the utility of equilibrium kinetic modeling in understanding the behavior of heavy metals during water-rock interactions and provides valuable insights into the potential environmental impacts of abandoned mine sites such as the Beck mine.

Compound contamination of soil with heavy metals copper (Cu) and lead (Pb) triggered by mining development has become a serious problem. To solve this problem, in this paper, corncob kernel, which is widely available and inexpensive, was used as the raw material of biochar and modified by loading CaAl-layered double hydroxides to synthesize biochar-loaded CaAl-layered double hydroxide composites (CaAl-LDH/BC). After soil remediation experiments, either BC or CaAl-LDH/BC can increase soil pH, and the available phosphorus content and available potassium content in soil. Compared with BC, CaAl-LDH/BC significantly reduced the available content of Cu and Pb in the active state (diethylenetriaminepentaacetic acid extractable state) in the soil, and the passivation rate of Cu and Pb by a 2% dosage of CaAl-LDH/BC reached 47.85% and 37.9%, respectively. CaAl-LDH/BC can significantly enhance the relative abundance of beneficial microorganisms such as Actinobacteriota, Gemmatimonadota, and Luteimonas in the soil, which can help to enhance the tolerance and reduce the enrichment ability of plants to heavy metals. In addition, it was demonstrated by pea seedling (Pisum sativum L.) growing experiments that CaAl-LDH/BC increased plant fresh weight, root length, plant height, catalase (CAT) activity, and protein content, which promoted the growth of the plant. Compared with BC, CaAl-LDH/BC significantly reduced the Cu and Pb contents in pea seedlings, in which the Cu and Pb contents in pea seedlings were reduced from 31.97 mg/kg and 74.40 mg/kg to 2.92 mg/kg and 6.67 mg/kg, respectively, after a 2% dosage of CaAl-LDH/BC, which was a reduction of 90.84% and 91.03%, respectively. In conclusion, compared with BC, CaAl-LDH/BC improved soil fertility and thus the plant growth environment, and also more effectively reduced the mobility of heavy metals Cu and Pb in the soil to reduce the enrichment of Cu and Pb by plants. [ABSTRACT FROM AUTHOR]

α-Tocopherol's (Vitamin E) antioxidant and anti-inflammatory properties may help reduce the progression of fibrosis in kidney by limiting tissue damage and inflammation induced by arsenic. Knowledge of the mechanisms of action of natural medicinal substances in arsenic toxicity will be improved by the analysis of the ameliorative effects of α-tocopherol. The goal of the current investigation was to determine whether Vitamin E can protect rats from nephrotoxicity caused by sodium arsenite (NaAsO2). Twenty-five Wistar rats were split into five groups viz: Group I with distilled water as control; Group II-IV with 8.4 (Low dose)/12.3 (Moderate dose)/16.4 mg/kg NaAsO2 (High dose); and Group V as in Gr. IV + 50 mg/kg α-Tocopherol. Both the doses were administered orally to rats for 60 days. α-tocopherol decreased the concentration of serum parameters like urea nitrogen (UN) and creatinine (CRT) whereas increased the concentration of albumin (ALB), acid phosphatase (ACP), alkaline phosphatase (ALP) and succinic dehydrogenase (SDH) (P <0.05). In comparison to control group, the transcript levels of p53 were significantly higher in the LDG, MDG, and HDG rats, respectively, by ~0.7 fold, ~0.4 fold, and ~0.5 fold. Similar to this, p21 transcript levels were higher in LDG, MDG and HDG groups than in those from the control group by ~0.2 fold, ~0.4 fold and ~0.6 fold, respectively. Additionally, as compared to rats in the control group, the levels of p27 transcripts were decreased by ~0.5 fold, ~0.5 fold, and ~0.4 fold in the LDG, MDG, and HDG rat populations, respectively. Co-administration of α-tocopherol with NaAsO2 showed decreased mRNA expression of p53 and p21 followed by increased mRNA expression of p27. In this investigation, it was discovered that α-tocopherol had a protective effect against renal damage brought on by NaAsO2. [ABSTRACT FROM AUTHOR]

Seed endophytes played a crucial role on host plants stress tolerance and heavy metal (HM) accumulation. Dysphania ambrosioides is a hyperaccumulator and showed strong tolerance and extraordinary accumulation capacities of multiple HMs. However, little is known about its seed endophytes response to field HM-contamination, and its role on host plants HM tolerance and accumulation. In this study, the seed endophytic community of D. ambrosioides from HM-contaminated area (H) and non-contaminated area (N) were investigated by both culture-dependent and independent methods. Moreover, Cd tolerance and the plant growth promoting (PGP) traits of dominant endophytes from site H and N were evaluated. The results showed that in both studies, HM-contamination reduced the diversity and richness of endophytic community and changed the most dominant endophyte, but increased resistant species abundance. By functional trait assessments, a great number of dominant endophytes displayed multiple PGP traits and Cd tolerance. Interestingly, soil HM-contamination significantly increased the percentage of Cd tolerance isolates of Agrobacterium and Epicoccum, but significantly decreased the ration of Agrobacterium with the siderophore production ability. However, the other PGP traits of isolates from site H and N showed no significant difference. Therefore, it was suggested that D. ambrosioides might improve its HM tolerance and accumulation through harboring more HM-resistant endophytes rather than PGP endophytes, but to prove this, more work need to be conducted in the future. [ABSTRACT FROM AUTHOR]

Hydrologic dynamics, sewage and industries determine the distribution and migration pathways of heavy metals in the natural environments including soils across the urbanized area. In this study, 323 stratified soil samples from a brownfield in Jiangsu Province, China, were collected to assess the heavy metals (Cu, Ni, Pb, Cd, As and Hg) contaminations. Contamination factor (Cfi), Nemerow pollution index (PIN) and enrichment factor (EFi) were evaluated to assess the heavy metal pollution, while sources of pollution were identified in combination with geo‐statistical, correlations and principal components analysis. Moreover, transport of Ni in soil profiles over the next 30 years was simulated using HYDRUS. The vertical distribution revealed that the soil surface (0–10 cm) had the highest concentration of heavy metal contamination. ICP‐MS measurements showed that the soil in the brownfield was enriched with Cu, Ni, Pb, Cd, As and Hg, where Ni was the most severe and prevalent contaminant. The results of source apportionment analysis showed that Ni, Cd, Pb and Cu were mainly derived from building materials and sewage discharge, while As and Hg may come from fossil fuel combustion and agricultural discharges from upstream river catchment. The migration of Ni was largely driven by the combination of hydrological variability including the flow and solute contaminant gradients in soils. Our work highlights the need for a comprehensive understanding of the complexity of hydrology, and sewage discharge in heavy metal dynamics and migration pathways in China's brownfield soil at regional and national scales. [ABSTRACT FROM AUTHOR]

Soil quality assessments, rarely applied to contaminated soils with metal(loid)s, consider ecological topics such as multifunctionality, resistance and resilience of microbial communities to perturbations, in addition to ecosystem services. In this study, the effect of metal(loid) contamination was evaluated in soils based on physicochemical and biological properties at different distances from an industrial complex and a Cu smelter. From these properties, soil quality indices (SQIs) were tested to compare their sensitivity and relationship with metal(loid) contamination. Enzyme activities and the average well color development, obtained from the community-level physiological profile, were the most suitable soil quality indicators. These variables along with some physicochemical properties [e.g. total organic carbon, pH, and available metal(loid) contents] were selected to develop SQIs. Five SQIs were calculated, from which the Multifunctionality assessment and the AreaSQI were found to be suitable methods to develop SQIs due to their higher discriminant power and relationship with metal(loid) contamination compared to other SQIs. They were validated using data from the literature, and both showed decreasing values at higher levels of metal(loid) contamination. Although the AreaSQI represents an attractive approach due to its visualization and easy interpretation, the multifunctionality approach showed a stronger sensitivity to chemical degradation by metal(loid)s in soil and offered an easier and faster calculation alternative. [ABSTRACT FROM AUTHOR]

Introduction: Long-termheavymetal contamination of soil affects the structure and function of microbial communities. The aim of our study was to investigate the effect of soil heavy metal contamination on microorganisms and the impact of different heavy metal pollution levels on the microbial interactions. Methods: We collected soil samples and determined soil properties. Microbial diversity was analyzed in two groups of samples using high-throughput sequencing technology. Additionally, we constructed microbial networks to analyze microbial interactions. Results: The pollution load index (PLI) < 1 indicates that the area is not polluted. 1 < PLI < 2 represents moderate pollution. PLI was 1.05 and 0.14 for the heavy metal contaminated area and the uncontaminated area, respectively. Cd, Hg, Pb, Zn, and Cu were identified as the major contaminants in the contaminated area, with the contamination factors were 30.35, 11.26, 5.46, 5.19, and 2.46, respectively. The diversities and compositions of the bacterial community varied significantly between the two groups. Compared to the uncontaminated area, the co-occurrence network between bacterial and fungal species in the contaminated area was more complex. The keystone taxa of the co-occurrence network in the contaminated area were more than those in the uncontaminated area and were completely different from it. Discussion: Heavy metal concentrations played a crucial role in shaping the difference inmicrobial community compositions. Microorganisms adapt to long-term and moderate levels of heavy metal contamination through enhanced interactions. Bacteria resistant to heavy metal concentrations may play an important role in soils contaminated with moderate levels of heavy metals over long periods of time. [ABSTRACT FROM AUTHOR]

In order to evaluate heavy metal contamination in Sidi River Basin mining area of Yangshuo County, Guangxi, the watershed hydrological model by ArcSWAT and the solute transport model by MT3DMS in groundwater modeling system (GMS) were combined to quantitatively analyze the migration of zinc and cadmium. The results suggest that utilizing ArcSWAT and GMS can more accurately determine the vertical infiltration amount and accurately groundwater numerical simulation. Without prevention and control measures, mine wastewater poses a significant pollution threat to groundwater environment. It is found that the content of zinc and cadmium in water sample of tailing cave outlet is 18. 62 mg / L and 0. 096 mg / L respectively, which is the source of heavy metal contamination in entire basin. Within simulated period of 20 years, the contaminated halo of zinc and cadmium reaches the river after about 16 d and 44 d respectively, and the farthest front end of halo is 2 303. 75 m and 1 887. 04 m away from the center. The longest part at both ends is 3 159. 57 m and 2 478. 57 m, and the widest part is 1 533. 54 m and 1 128. 36 m. The mass of zinc and cadmium entered basin is 3 512. 44 g and 18. 15 g, and flowed out is 1 640. 49 g and 8. 47 g, remaining proportion are 53. 28% and 53. 33% separately in basin. There are existing research results show that Solanum nigrum L. is hyperaccumulator for cadmium that the highest accumulation in plant is 1 084. 4 mg / kg and strong tolerance to zinc with enrichment exceeding 1 000 mg / kg. Therefore, a simulated circumstance is set up to evaluate the ecological restoration of tailings reservoir. The content of zinc is 0. 284 mg / L and cadmium is 0. 002 mg / L in tailings pond which is taken as alternative contaminated source. The migration speed of zinc along river valley reduces from 94. 38 m/ a to 80. 78 m/ a, and cadmium reduced from 86. 09 m/ a to 69. 13 m/ a during simulated period. The maximum halo of zinc reduced from 3. 80 × 10 6 m ² to 2. 50 × 10 6 m 2 and of cadmium from 1. 67 × 10 6 m 2 to 1. 29 × 10 6 m ² . It indicated that the ecological restoration has achieved better effects and proposed continue investing in construction. According to simulation results, it is recommended to construct anti-seepage curtains and other prevention measures at the mine tunnel outlet. And prevention areas are classified to strengthen groundwater quality monitoring. Simultaneously, emergency plans for groundwater accidents can be formulated to avoid further deterioration of contamination. [ABSTRACT FROM AUTHOR]

Soil washing has been widely applied and studied in the remediation of heavy metal contamination soil. However, it proves easily limited by soil texture. To this end, the method of freeze-thaw and washing is used to enhance washing efficiency of clayey soils. An array of experiments of laboratory indirectness washing and freeze-thaw and washing were carried out to investigate the removal effect of single and compound washing on heavy metals. The results showed that the stability of soil aggregates would be destabilized by repeated freezing and thawing, contributing to a sufficient contact reaction between eluents and contaminations. The process can also remove heavy metals under a lower liquid-solid ratio, thus reducing the risk of secondary contamination of the soil environment. The eluent has a certain viscosity, which increases the viscosity of the pore water. Accordingly, the water migration resistance increases and inhibits the soil frost heaving-water intake, resulting in the reduction of removal efficiency. The removal effect of compound washing is preferable to the single washing, proving effectively removing the weak acid extractable fractions, reducible fractions, as well as residue fractions of Cd and the weak acid extractable fractions and reducible fractions of Pb in the soil. The research results provide a novel method of reusing natural cold energy to remedy clayey soil contamination with heavy metals. [ABSTRACT FROM AUTHOR]

Main conclusion: Heavy metal pollution caused by human activities is a serious threat to the environment and human health. Plants have evolved sophisticated defence systems to deal with heavy metal stress, with proteins and enzymes serving as critical intercepting agents for heavy metal toxicity reduction. Proteomics continues to be effective in identifying markers associated with stress response and metabolic processes. This review explores the complex interactions between heavy metal pollution and plant physiology, with an emphasis on proteomic and biotechnological perspectives. Over the last century, accelerated industrialization, agriculture activities, energy production, and urbanization have established a constant need for natural resources, resulting in environmental degradation. The widespread buildup of heavy metals in ecosystems as a result of human activity is especially concerning. Although some heavy metals are required by organisms in trace amounts, high concentrations pose serious risks to the ecosystem and human health. As immobile organisms, plants are directly exposed to heavy metal contamination, prompting the development of robust defence mechanisms. Proteomics has been used to understand how plants react to heavy metal stress. The development of proteomic techniques offers promising opportunities to improve plant tolerance to toxicity from heavy metals. Additionally, there is substantial scope for phytoremediation, a sustainable method that uses plants to extract, sequester, or eliminate contaminants in the context of changes in protein expression and total protein behaviour. Changes in proteins and enzymatic activities have been highlighted to illuminate the complex effects of heavy metal pollution on plant metabolism, and how proteomic research has revealed the plant's ability to mitigate heavy metal toxicity by intercepting vital nutrients, organic substances, and/or microorganisms. [ABSTRACT FROM AUTHOR]

Copper (Cu), with many documented cases of Cu toxicity in agriculture lands, is becoming an increasingly common issue in the world, but fewer studies have been conducted on its effects and alleviation strategies through the use of titanium dioxide nanoparticles (TiO2-NPs) and silicon (Si). For this purpose, we have conducted a pot experiment to determine the effects of seed priming with TiO2-NPs i.e., 40 mg L−1 and Si i.e., 3 mM on wheat (Triticum aestivum L.) under different levels of Cu in the soil i.e., 0 (no Cu), 100 and 200 mg kg−1. Results from the present study showed that the increasing concentrations of Cu in the soil caused a significant decrease in the plant growth and biomass, chlorophyll pigments and gas-exchange characteristics, sugar content, essential ions in the roots and shoots of the plant, compared to control. In addition, increasing concentration of Cu also increases oxidative damage, enzymatic and non-enzymatic enzymes along with their gene expression, organic acids exudation patter and Cu concentration in the roots and shoots of the plant. The negative impact of Cu toxicity can overcome the application of TiO2-NPs and Si, which ultimately increased plant growth and biomass by capturing the reactive oxygen species (ROS), and decreased oxidative stress in T. aestivum by decreasing the Cu contents in the roots and shoots of the plants. Research findings, therefore, suggest that the combined application of TiO2-NPs and Si can ameliorate Cu toxicity in T. aestivum, resulting in improved plant growth and composition under metal stress, as depicted by balanced exudation of organic acids. [ABSTRACT FROM AUTHOR]

This study investigates the heavy metal contamination of soils and suspended sediments in the Nurzec River catchment (Eastern Poland), focusing in particular on the effects of catchment land use. The fingerprinting technique has been combined with the classic, Igeo, and EF index-supported contamination analysis to identify heavy metals sources. A wide range of elements (31 chemical elements including heavy metals) allowed the author to analyse the pathways and to identify the pressures of heavy metal contamination. The developed statistical models of heavy metal source distribution displayed results at a statistically significant level. The results have revealed the significant impact of land use connected with urban areas (URBAN) and pastures (PAST), which together constitute less than 20% of the river catchment area. These results are relevant to the local authorities and stakeholders, as they highlight the significant impact of low-density urban areas that are not locally considered as the major sources of heavy metal pollution. These results will contribute to sustainable decisions in the field of contaminated catchment area remediation. [ABSTRACT FROM AUTHOR]

Microorganisms in the soil that have been contaminated with heavy metals for a long-time exhibited resistance to heavy metals. In recent years, the use of resistant microbes and heavy metal-tolerant plants to repair heavy metal-contaminated soil has become an increasingly hot subject. In this study, heavy metal-tolerant bacteria ZG7 was isolated from the mining soils and injected into Bidens pilosa L. and Medicago sativa L.. The results revealed that: (1) Compared to the non-inoculated group, inoculation with ZG7 notably increased the dry weight and chlorophyll content in plants under heavy metal stress, as well as promoted the content of several types of antioxidant chemicals; (2) Combined remediation improved soil enzyme activities, with soil catalase, sucrase, and phosphatase activities remarkably increased by 136.06%, 124.17% and 180.14% in the ZG7- Bidens pilosa L.; And soil catalase, urease, and sucrase activities promoted by 68.07%, 130.08% and 239.79% in the ZG7- Medicago sativa L.; (3) The content of Pb and Zn in the ZG7- Medicago sativa L. combination soil were considerably lower (9.28% and 6.2%, respectively) than no strain group, but there was no substantial change in soil heavy metal content when combined with the Bidens pilosa L. remediation when compared to no strain group. In summary, the combination of strain ZG7 and plants had a good effect on the remediation of heavy metal contaminated soils, and ZG7- Medicago sativa L. had the best effect, which is a reliable technique for effective control of heavy metal pollution. This study provided theoretical support for microbial-phytoremediation joint remediation. [ABSTRACT FROM AUTHOR]

We determined the levels of nine heavy elements in water, sediment, and the edible tissues of three frequently eaten fish species collected from the five polluted rivers in different divisions of Bangladesh. These samples were randomly taken from five rivers and analyzed by Flame Atomic Absorption Spectroscopy. We found seasonal fluctuations in the hierarchy of mean concentration for different heavy metals in five rivers' fish, water, and sediments. In the water, the concentrations of Cd, Cr, Cu, Fe, Mn, Pb, Zn, Ni, and Hg ranged from 0.010-0.081, 0.016- 5.531, 0.013-2.445, 0.860-22.924, 0.043-1.424, 0.015-0.933, 0.091-1.451, 0.012-2.888, and 0.010-0.032 mg/l where in the sediment the concentrations ranged from 0.1-1.47, 4.21-284.1, 0.12-28.46, 1860-14971.33, 122.1-480.8, 0.84-42.15, 2.14-210.35, 15.3-30.4, and 0.17-10.44 mg/kg. For fishes concentrations ranging from BDL-0.78, 0.04-86.45, 0.01-1.67, 4.19-102, 0.08- 0.94, 0.01-0.99, 0.08-9.56, 0.01-4.56, and BDL-0.2 mg/kg were reported for the above metals order respectively. The highest concentration (mean) of Cr and Fe in waters and sediments was 1023 times and 13020.72 % higher than WHO's standard and Toxicity Reference Values (TRV), respectively. Besides, the bioaccumulation factors (BAF) of the selected elements for the studied fishes were found to be between 0.036-626.25, where the pollution load index (PLI) for the five rivers ranged from 0-0.95 and the concentration factor (CF) found between 0.02-4.03. Estimated daily Intake (EDI) as well as Target hazard quotients (THQs) analyses revealed potential risks for fish consumers, particularly the level of some metals exceeding the WHO/FAO's tolerable limit, which indicates that the rivers' water and fish are dangerous to humankind. [ABSTRACT FROM AUTHOR]

The research aimed to determine the influence of endophytic fungi on tolerance, growth and phytoremediation ability of Prosopis juliflora in heavy metal–polluted landfill soil. A consortium of 13 fungal isolates as well as Prosopis juliflora Sw. DC was used to decontaminate heavy metal–polluted landfill soil. Enhanced plant growth (biomass and root and shoot lengths) and production of carotenoids, chlorophyll and amino acids l-phenylalanine and l-leucine that are known to enhance growth were found in the treated P. juliflora. Better accumulations of heavy metals were observed in fungi-treated P. juliflora over the untreated one. An upregulated activity of peroxidase, catalase and ascorbate peroxidase was recorded in fungi-treated P. juliflora. Additionally, other metabolites, such as glutathione, 3,5,7,2′,5′-pentahydroxyflavone, 5,2′-dihydroxyflavone and 5,7,2′,3′-tetrahydroxyflavone, and small peptides, which include Lys Gln Ile, Ser Arg Ala, Asp Arg Gly, Arg Ser Ser, His His Arg, Arg Thr Glu, Thr Arg Asp and Ser Pro Arg, were also detected. These provide defence supports to P. juliflora against toxic metals. Inoculating the plant with the fungi improved its growth, metal accumulation as well as tolerance against heavy metal toxicity. Such a combination can be used as an effective strategy for the bioremediation of metal-polluted soil. [ABSTRACT FROM AUTHOR]

Mining of manganese leads to significant heavy metal contamination, affecting the adjacent ecosystems. Therefore, it is crucial to monitor heavy metal levels in mining areas. This study examined heavy metal concentrations (Cr, Mn, Cu, Zn, Sr, Mo, Cd, and Pb) in vegetation and soil within the wetland area of the Zhaiying manganese slag discharge field in Songtao County, Guizhou Province, China. The assessment utilized the single-factor pollution index method (Pi), Nemerow comprehensive pollution index method (Pn), and correlation analysis. Two local plant species, Philonotis and Spirogyra, were used as sample materials. The findings revealed varying degrees of heavy metal contamination across all sites, with intensity increasing closer to the slag discharge area. Notably, Philonotis displayed a higher heavy metal accumulation capacity than Spirogyra. Statistical analysis revealed a significant positive correlation (P < 0.05) between Philonotis and soil heavy metals (Mn, Zn, and Cd) and between Spirogyra and specific soil heavy metals (Mn and Sr). Linear fit analysis indicated a strong association between Philonotis and soil manganese, suggesting that Philonotis is an effective bioindicator for monitoring environmental heavy metal pollution in slag discharge field wetlands. The manganese content in Philonotis exceeded 10,000 mg/kg, indicating potential as a hyperaccumulator, warranting further investigation. This research supports the use of Philonotis as a biological tool for monitoring heavy metal pollution in wetland ecosystems affected by manganese mining. [ABSTRACT FROM AUTHOR]