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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]

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]

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]

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]

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]

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]

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]

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]

In this study, the amplitude data of geo-radar electromagnetic (EM) waves were extracted using EM wave property analysis software, and the variation relationship between the heavy metal concentrations measured in the field and the geo-radar EM wave was analyzed to construct the characteristic function of geo-radar signal waves and heavy metal pollution. Heavy metal concentrations were obtained through inversion and compared with the measured heavy metal concentrations to further explore the feasibility of inversion by geo-radar signal waves. The variations of electromagnetic wave amplitude properties with burial depth on different profiles were analyzed, and it was concluded that the variation of the mean absolute amplitude for geo-radar electromagnetic waves was most consistent with the variation in burial depth. The trend of mean absolute amplitude was found to have a significant correlation coefficient (0.8329). The root mean square (RMS) amplitude fluctuated between 2000 and 3000 as the concentration stayed in the range of 250–300 mg/kg and stabilized around 1000 in the concentration range of 50–100 mg/kg. The mean absolute amplitude showed a similar trend to the RMS amplitude, displaying decreasing amplitude within the concentration range of 50–100 mg/kg. The characteristic function of heavy metal pollution concentration and EM wave amplitude was expressed as c = - 0.00006 × F a 2 +0.36 × F a - 247.52 , which could be used to predict the actual heavy metal concentration changes through the changes in mean absolute amplitude. This provides a theoretical foundation for developing a model of the relationship between heavy metal pollution concentrations and electromagnetic wave amplitudes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The concept of circular economy, aiming at increasing the sustainability of products and services in the water and other sectors, is gaining momentum worldwide. Driven by this concept, novel bio-composite materials produced by recovering resources from different parts of the water cycle are now manufactured in The Netherlands. The new materials are used for different products such as canal bank protection elements, as an alternative to similar elements made of hardwood. As much as these new materials are appealing from the sustainability point of view, they may leach toxic substances into the aquatic environment given some of their ingredients, e.g., cellulose recovered from wastewater treatment. Therefore, a methodology for the assessment of related environmental risks is needed and it does not exist currently. This paper addresses this knowledge gap by presenting a framework for this. The framework is based on European environmental risk assessment guidelines, and it includes four key steps: (i) hazard identification, (ii) dose–response modelling, (iii) exposure assessment and (iv) risk characterisation (i.e. assessment). As part of the first step, laboratory leaching tests were carried out to evaluate the potential release of specific chemical substances such as heavy metals and resin compounds into the aquatic environment. Laboratory test results were then used as input data to evaluate the risk of potential leaching from canal bank protection elements into surface water. A deterministic model was used first to identify the chemicals exceeding the guideline threshold. Subsequently, a stochastic model was applied to evaluate the environmental risks across a range of leachate concentrations and water velocities in the canal, thereby simulating a broader spectrum of possible situations. The risk analyses were conducted for four alternative bio-composite materials made of different ingredients, two different flow conditions (stagnant water and advective flow) in two types of canals (wide ditch and primary watercourse) and for two different water levels based on season conditions (summer and winter conditions). The results obtained from leaching tests identified Cu, Mn, Zn, styrene and furfuryl alcohol as potentially troublesome chemicals. In the case of stagnant water, the absence of a flow rate increases the residence time of the chemicals in the surface water, resulting in a higher PEC/PNEC (i.e. risk) value. However, under stagnant case conditions, environmental risks for all chemicals considered turned out to be below the safety threshold. In the advective case, the existence of a flow rate, even at low velocities simulating the conditions of 'almost no flow,' contributes to increased dilution, resulting in lower PEC/PNEC ratio values. The results presented here, even though representing real-case scenarios, are only indicative as these are based on laboratory leaching tests and a number of assumptions made. Additional field tests involving collecting and analysing water and sediment samples from the canal where the canal bank protection elements are located, over a prolonged period, are required to come up with more conclusive findings. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A total of 30 samples from the downwind direction of a certain electroplating company in Jiaxing were collected in layers to analyze their heavy metal content. The soil risk assessment was conducted from the perspective of ecological and human health risks using the ground accumulation index method and human health risk assessment method. The results showed that in all samples, cadmium and arsenic far exceeded the soil background values, with an average exceeding multiple of 14.31 and 64.42, respectively, and a exceeding rate of 100%. After evaluation by the ground accumulation index, among these six heavy metals, arsenic and cadmium belong to extremely serious pollution levels. The human health risk assessment of electroplating plants found that in the exposure risk assessment, the ingestion value was much greater than the harm caused by breathing and skin, and the maximum exposure damage value of arsenic to children and adults was 4.17 × 10–3, among the carcinogenic risks, the risk brought by consumption is much greater than the respiratory and skin carcinogenic risk index, with the highest value score of 3.37 for cadmium, arsenic, and zinc carcinogenic risks 3.37 × 10–6, 2.42 × 10–3, 1.10 × 10–4. [ABSTRACT FROM AUTHOR]

The present work studied the impact of different levels of PVC–microplastics (PVC–MPs), namely 0 (no PVC–MPs), 2, and 4 mg L−1, along with mercury (Hg) levels of 0 (no Hg), 10, and 25 mg kg−1 in the soil, while concurrently applying titanium dioxide–nanoparticles (TiO2–NPs) at 0 (no TiO2–NPs), 50, and 100 µg mL−1 to sorghum (Pennisetum glaucum L.) plants. This study aimed to examine plant growth and biomass, photosynthetic pigments and gas exchange characteristics, oxidative stress indicators, and the response of various antioxidants (enzymatic and non-enzymatic) and their specific gene expression, proline metabolism, the AsA–GSH cycle, and cellular fractionation in the plants. The research outcomes indicated that elevated levels of PVC–MPs and Hg stress in the soil notably reduced plant growth and biomass, photosynthetic pigments, and gas exchange attributes. However, PVC–MPs and Hg stress also induced oxidative stress in the roots and shoots of the plants by increasing malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage (EL) which also induced increased compounds of various enzymatic and non-enzymatic antioxidants and also the gene expression and sugar content. Furthermore, a significant increase in proline metabolism, the AsA–GSH cycle, and the pigmentation of cellular components was observed. Although, the application of TiO2–NPs showed a significant increase in plant growth and biomass, gas exchange characteristics, enzymatic and non-enzymatic compounds, and their gene expression and also decreased oxidative stress. In addition, the application of TiO2–NPs enhanced cellular fractionation and decreased the proline metabolism and AsA-GSH cycle in P. glaucum plants. These results open new insights for sustainable agriculture practices and hold immense promise in addressing the pressing challenges of heavy metal contamination in agricultural soils. [ABSTRACT FROM AUTHOR]

Biochar, as a soil amendment, can be applied to remediate heavy metal (HM) contaminated farmland. However, there is little research on the effect of tobacco biochar (TB) derived from tobacco waste on HM controlling in edible parts of vegetables. In this study, the impact of two TB levels on the plant growth, copper (Cu) and cadmium (Cd) accumulation in the edible parts of lettuce and chrysanthemum, and on Cu and Cd bioavailability of rhizosphere soil was investigated through in-situ field experiments. The results showed that TB has rich oxygen containing functional groups, high porosity, high nitrogen adsorption capacity. The addition of 5 t ha−1 and 10 t ha−1 TB significantly increased the shoot biomass of chrysanthemum, but had no effect on the growth of lettuce. Two levels of TB significantly increased the pH value, but decreased the available Cu and Cd concentrations of rhizosphere soil, thereby reducing the Cu and Cd accumulations in the edible parts of lettuce and chrysanthemum. The findings provided effective evidences that TB derived from tobacco waste is an efficient strategy for controlling Cu and Cd accumulation in the edible parts of vegetables to ensure agri-product safety production in HM-polluted farmland. [ABSTRACT FROM AUTHOR]

In this study, we present a novel colorimetric method for the precise and sensitive detection of Hg ions utilizing silver nanoparticles (AgNPs) produced and stabilized in an aqueous medium using Poly allyl amine hydrochloride (PAH). Nanoparticles were prepared from silver nitrate and NaBH4 along with CTAB at 26 ± 2 °C with an average size of 30.21 ± 6.5 nm. The prepared AgNPs solution exhibited yellowish brown color with a surface Plasmon peak at 420 nm. By adding Hg ions, the yellow color of the solution was transformed into a colorless suspension, and the color change was proportional to the Hg ion concentration. The presence of other metal ions had no effect on the color (sensitivity); confirming the selectivity of CTAB stabilized PAH capped AgNPs towards Hg ions. The generated probe has a 1 nM low detection limit when measured using a UV–visible spectrophotometer. The proposed approach has the potential to be utilized in real-time environments with greater precession by applying RGB values to make a revolutionary sensor using visible light imaging technique. [ABSTRACT FROM AUTHOR]

The northern part of James Ross Island is the largest deglaciated area in the Antarctic Peninsula region with a unique ecosystem created during the Late Glacial. This research aims to evaluate the degree of contamination of the locality with toxic metals (As, Hg, Cd, and Pb) through bioindicators in the aquatic environment—colonies of cyanobacteria and algae. For this purpose, bottom lake sediments of Big Lachman Lake were studied for contents of Fe, As, Hg, Cd, Pb, Cr, Co, Ni, Cu, and Zn, as well as samples of cyanobacterial mat, in which Fe, As, Hg, Cd, and Pb were determined. Metal contents were determined by means of inductively coupled plasma optical emission spectrometry and atomic absorption spectrometry. The contents of metals in sediments did not differ from the usual values in the area of the Antarctic Peninsula. The bioaccumulation of metals in cyanobacterial mat was evaluated by calculating enrichment factors (the calculation to Fe as a reference element). According to this method, moderate pollution of Big Lachman Lake was confirmed for Hg and Cd. [ABSTRACT FROM AUTHOR]

The contamination of agricultural soils by toxic heavy metals, such as As, Cd, and Pb, is of great concern for crop safety as well as environmental and public health. Various adsorbents for the in situ immobilization of these metals have been widely studied, but researches on the potential and superiority of metal adsorption in agricultural soil amendments are still lacking. This study was conducted to investigate the nature of their sorption processes on soil amendments including slaked lime (SL), phosphogypsum (PG), bone meal (BM), and biochar (BC) using a series of laboratory batch tests. The Langmuir adsorption isotherm was used to predict sorption parameters. The experimental data fitted reasonably well on the Langmuir model with high correlation coefficients (R2 = 0.64–0.99) suggesting that monolayer sorption/complexation/precipitation was the dominant mechanism. Among the amendments, SL achieved the highest maximum adsorption capacity (qmax) for As and Cd at 714.3 and 2000 mg g−1, respectively, while PG had the highest qmax for Pb at 196.08 mg g−1. The results indicate that there is no direct correlation between sorption stability and maximum adsorption capacity. Among the sorbents, BC had the highest sorption stability for As (0.007 L mg−1), Cd (0.121 L mg−1), and Pb (2.273 L mg−1), respectively, albeit the qmax values for these three metals were not high. This indicates that the As, Cd, and Pb sorbed on biochar tended to be more stable than those retained on other amendments. While a large sorption capacity is important, our results provide important insights into the metal sorption stability/energy of adsorbents that will aid in the development of long-term management efficiency strategies to rehabilitate metal-contaminated arable soils. [ABSTRACT FROM AUTHOR]

Aims: Small islands of safety, accompanied by clonal integration, could have important impacts on plant performance in stressful environments. Although the effects of environmental heterogeneity and clonal integration on clonal plant growth have been well studied, little attention has been paid to the impacts of islands of safety and the interaction with clonal integration on plant performance in the context of soil contamination. Methods: We conducted an experiment consisting of two soil treatments (with/without an island of safety, i.e., a patch with uncontaminated soil, located in the middle of cadmium-contaminated soil) and two stolon connection statuses (stolon between the mother ramets and their daughter ramets was either severed or kept connected) using the stoloniferous clonal plant Glechoma longituba. Results: Overall, the presence of the safe island significantly increased the number of ramets, total mass, leaf mass, and stolon mass of the daughter ramets and the whole clone. Clonal integration significantly decreased the number of ramets, total mass, leaf mass, and stolon mass of mother ramets. The presence of the island of safety enhanced total mass, leaf mass, and stolon mass of the mother ramet in the group with severed stolons and root mass and root to shoot ratio in the group with connected stolons. Conclusions: Building islands of safety can contribute to daughter ramet growth in a contaminated ecosystem, which suggests assembling smaller safe islands coupled with clonal plants with strong clonal integration may be a promising measure to vegetation restoration in heavy metal contaminated ecosystem. [ABSTRACT FROM AUTHOR]

Green tea is one of the most widely consumed beverages worldwide, also in Morocco. It has numerous health benefits due to its various bioactive compounds. However, there are concerns about the contamination of green tea by some toxic heavy metals, such as lead (Pb) and cadmium (Cd). The aim of this study was to investigate the contamination levels of Pb and Cd in green tea samples taken from six different brands in Morocco by using graphite furnace atomic absorption spectrometry. Cd was detected in 59 out of 76 samples in the range of 0.002–0.743 μg/g, accounting for 77.63% of the analyzed samples, with a mean value of 0.121 ± 0.006 μg/g. For the rest of the samples (22.37%), Cd were below the limit of detection (LOD). For Pb, 67 samples (88.16%) were reported to have Pb levels ranging from 0.002 to 1.155 μg/g, with a mean value of 0.159 ± 0.006 μg/g. For the remaining samples (11.84%), Pb levels were < LOD. Samples from brand D had the highest content of Pb (1.145 μg/g) and Cd (0.728 μg/g) among the samples analyzed. Pb levels in all green tea samples were far below the standard limits set by the World Health Organization (WHO) (10 μg/g) and China (5 μg/g). However, for Cd levels, 3 green tea samples exceeded the recommended maximum limit (0.3 μg/g) set by WHO. Both the Target Hazard Quotient (THQ) values for individual elements and the Hazard Index (HI) values for Cd and Pb were far below 1. [ABSTRACT FROM AUTHOR]

Although sewage water (SW) is a source of nutrients, it also causes heavy metal accumulation in soil; especially, lead (Pb+) contamination of soil is a serious concern in agriculture. Soil contaminants limit the bioavailability of nutrients to plants. So, they affect plant growth and produce quality. Therefore, a pot experiment was conducted to investigate the effect of zeolite soil amendment on the accumulation of Pb+ in tomato crop grown with SW irrigation. The pot media of SW-irrigated plants was amended with different concentrations of zeolite, viz., 0.75%, 1.50%, and 2.25%. The results showed that the application of 0.75% zeolite increased leaf area, plant height, fruit number, and plant fresh and dry biomasses by 37%, 17%, 14%, 24%, and 7% compared to freshwater irrigation. Moreover, the lowest zeolite dose also led to higher chlorophyll content (68.02 SPAD) compared to SW-irrigated plants (55.13 SPAD). Similarly physiological traits, such as A, gs, and E, were higher (17.68 µmol m−2 s−1, gs 0.28 mmol m−2 s−1, and 7.88 mmol m−2 s−1, respectively) in 0.75% zeolite-treated plants than in SW-irrigated plants (12.99 µmol m−2 s −1, 0.19 mmol m−2 s−1, and 7.00 mmol m−2 s −1, respectively). On the contrary, a reduced level of hydrogen peroxide and malondialdehyde and decreased activity of antioxidant enzymes were observed in low-dose zeolite applied plants. Zeolite reduced Pb+ accumulation in tomato plants as compared to SW-irrigated plants, whereby Pb accumulation in the fruits of SW-irrigated plants was 80% more than those of zeolite + SW–treated plants. Conclusively, this study has revealed the improvement in morphological and physiological growth attributes of the SW-irrigated tomato plant in response to zeolite application. [ABSTRACT FROM AUTHOR]

Various techniques are employed nowadays to lessen the harmful consequences of high soil concentrations of heavy metals (HMs). In this instance, a relatively novel technique to lessen the toxicity of HMs is the use of biochar. In this study, in order to investigate the effect of sugarcane bagasse biochar on improving the growth of corn (Zea mays L.) in Cadmium (Cd) and lead (Pb) contaminated soil; a pot experiment was conducted in a randomized complete block design. The variables included planting maize, which was done in two independent experiments for Cd and Pb, three levels of Cd (0, 40, and 80 mg kg-1 of soil from CdSO4.8H2O), three levels of Pb (0, 400, and 800 mg kg-1 of soil from PbSO4), and two levels of sugarcane bagasse biochar (0 and 5% by weight). The results showed that increasing Cd and Pb treatments significantly increased the concentrations of these two elements in the maize shoots and roots and markedly decreased the dry weight of the shoots and roots by 35 to 45% and between 55 and 65%, respectively. A rise in Cd and Pb content was also accompanied by a notable decrease in the chlorophyll index, leaf area, plant height, and dry weight of roots and shoots. However, the use of sugarcane bagasse biochar increased the chlorophyll index, leaf area, plant height, and dry weight of the roots and shoots as a result of a considerable decrease in the concentration of Cd and Pb in the roots and shoots. In compared to the control, the translocation coefficient and bioconcentration factor reduced after the application of 5% sugarcane bagasse biochar. According to the findings, sugarcane bagasse biochar may stabilize and adsorb Pb and Cd from soil. It follows that adding sugarcane bagasse biochar to HM-contaminated soils is an appropriate remedial treatment that will promote plant development. [ABSTRACT FROM AUTHOR]

Phytoextraction is an efficient strategy for remediating heavy metal-contaminated soil. Chelators can improve the bioavailability of heavy metals and increase phytoextraction efficiency. However, traditional chelators have gradually been replaced due to secondary pollution. In this study, a typical organic acid (citric acid, CA) and a novel biodegradable chelator (poly-glutamic acid, PGA), were investigated using pot experiments to compare the phytoextraction efficiency of Solanum nigrum L. (a Cd (hyper)accumulator) for cadmium (Cd) and lead (Pb) in contaminated soil. The results showed CA and PGA significantly improved plant growth, and total Cd and Pb amounts of S. nigrum, both CA and PGA significantly increased the shoot Cd and Pb concentrations. However, only PGA significantly increased the root Pb concentration. CA and PGA application promoted the bioavailability of Cd and Pb in rhizosphere soils and their translocations from roots to shoots in S. nigrum. Both CA and PGA increased the phytoextraction efficiency of Cd and Pb in S. nigrum plants, and the PGA for Cd and Pb phytoextraction was more effective than CA. Our findings demonstrate that the biodegradable chelator PGA has great potential for enhancing phytoextraction from compound Cd–Pb contaminated soils, suggesting that biodegradable chelator-assisted phytoextraction with (hyper)accumulator is strongly recommended in severely contaminated sites. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) is an excellent membrane-forming material with unique two-dimensional transport channels and excellent adsorption properties for heavy metal contaminants. However, swelling under cross-flow conditions and long-term water immersion leads to poor separation performances. To improve the stability of GO membrane materials, we propose a PVA-integrated graphene oxide/attapulgite membrane (GOAP) with a 3D microstructural arrangement of "brick–mortar-brick." The addition of PVA as mortar reinforces the strength of the structures via induced hydrogen bonding within the 3D water transport network. Furthermore, the Al2O3 ceramic substrate pre-treated with (3-aminopropyl) triethoxysilane (APTES) provided high mechanical stability to the composite membrane, extending the membrane's stability beyond a month of immersion without swelling or shedding. The PVA-integrated GO/ATP composite membrane maintained a rejection rate of 99% for Cu2+ solution (100 mg/L) in a 26-h continuous with nearly 100% rejection for various metals ions such as Cu2+, Ni2+, Pb2+, and Cd2+. The membrane exhibited a water flux of 20.7 L·m−2·h−1, which was 15.9-fold high than the pure GO membrane (GOM). The high water flux and heavy metal filtration rate with superior stability proved the practical suitability of the composite film for removing heavy metal ions. [ABSTRACT FROM AUTHOR]

The aim of this work was to determine the concentrations of selected mutagenic elements (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Se) in raw ewe milk from undisturbed environment in Orava region, northern Slovakia. There are possible sources of some of the analyzed metals which may be distributed from the metallurgical plants located in the Ostrava region, Czech Republic, and Katowice, Poland. In total, forty milk samples were analyzed in June and August using an inductively coupled plasma optical emission spectrometry. The differences in elements concentrations between the seasonal periods were not significant except of iron (p < 0.0001). The concentrations of most of the metals in ewe milk were low and under the permissible or recommended limits. However, arsenic and selenium concentrations were elevated and could pose a risk of the mutagenic effect, particularly in children. The frequency of element occurrence in June was as follows: Se > Fe > As > Cu > Mn > Ni > Co > Pb > Cr > Cd, and in August: Se > Fe = As > Cu > Mn > Pb > Co > Ni > Cr > Cd. The correlation analysis revealed very strong positive correlation between Cu:Pb (p < 0.05), very strong negative correlation between Fe:Se (p < 0.05). The strong correlations were also found between other elements. The present study showed that milk produced in the relatively undisturbed environment might contain various mutagenic elements. The relationships between the elements might result in the additive or synergistic effects of elements and increase the risk of their mutagenic effects even in low concentrations. Therefore, attention must be paid to the monitoring of metals in the areas where food sources destined especially for child nutrition are produced. [ABSTRACT FROM AUTHOR]

In this investigation, the metal concentrations (Co, Mn, Cr, Zn, Cu, Pb, As, Cd, and Ni) were estimated in the surface sediments of Lake Pykara. The impending contagion and toxicity of metals were dictated by assessing the EF, Igeo, and ecological risk assessment. The mean concentrations of different metals in this investigation are more prominent than the background esteems of average shale aside from the estimations of Ni and Mn. The Cd and mCd esteem uncover that the lake is highly contaminated to extremely contaminating. The Igeo esteem affirmed that the sediments are strong to very strongly pollute. According to the risk assessment estimates based on Er, RI, and PLI, the sediments of Lake Pykara range from extremely high potential ecological risk to the highest ecological risk category. Pearson's correlation is additionally recommending that they most likely originated from a similar source of occurrence. The study also reveals the most significant information about the human impacts on the sediments of Lake Pykara. [ABSTRACT FROM AUTHOR]

Contamination with cadmium (Cd) and lead (Pb) in rice and paddy soil threatens food safety and human health. This study determined the effects of oyster shell amendment (0, 6, and 12 g kg−1) on the mobility and uptake of Cd and Pb by two rice plants (ZY18, japonica and DL5, indica) in contaminated paddy soil. Oyster shell amendment significantly increased the pH of soil and pore water, and decreased the DTPA-extractable Cd concentration in soil, but not the Cd concentration in pore water. Furthermore, the DTPA-extractable Pb concentration in rhizosphere soil was not significantly influenced by oyster shell addition. Application of oyster shell reduced the Pb concentration in pore water and Pb uptake by both cultivars, but excessive application (12 g kg−1) resulted in Cd accumulation in tissues for ZY18. Furthermore, oyster shell addition significantly increased the dissolved organic carbon, calcium, and magnesium concentrations in soil pore water, and decreased glutathione and phytochelatin levels in roots, all of which alleviated heavy metal toxicity and improved rice growth. These results demonstrate that amendment with the appropriate amount of oyster shell, combined with rice cultivar type, could simultaneously reduce Cd and Pb accumulation in rice grown in heavy metal–contaminated soil. [ABSTRACT FROM AUTHOR]

Oman Sea region is a major gateway for international and local shipping. Metal pollution of aquatic environment is primarily caused by such shipping and industrial activities. Agricultural runoffs are also of concern. Seaweed contamination with heavy metals in this area is therefore a distinct possibility. We examined seaweed of Oman Sea for heavy metal content and potential risk of its consumption to the public. During winter of 2019, water, sediment, and seaweed were collected along twelve stations on the coast of Oman Sea. Triplicates of each sample were analyzed for metal content by atomic absorption spectroscopy. Biomarkers of metals in seaweed (metallothionein and phytochelatin) were also analyzed. A significant positive correlation exists among levels of Zn, Ni, Pb, Cr, Cu, and Fe in water, sediment, and seaweed (P < 0.05). Cadmium correlations were weak. The highest levels of metallothionein and phytochelatin were found in brown and red seaweed (118.6 µg/g wet weight, 16.4 amol/cell; 111.4 µg/g ww, 12.1 amol/cell), respectively. For nickel and lead, human consumption of red, brown, and green seaweed was associated with "some health hazard," with a target hazard quotient of > 1. We conclude that concerns over heavy metal contamination of some parts of Oman Sea are valid, and we invite policy makers to implement measures for protection of public and environment from metal toxic effects in the region. [ABSTRACT FROM AUTHOR]

Frequent discharge of heavy metals from textiles, tanneries and other anthropogenic sources occurs in Dhaka City, the capital of Bangladesh, contaminating the major rivers. Accumulation of heavy metals such as chromium (Cr), cadmium (Cd), lead (Pb), nickel (Ni) and zinc (Zn) in water, sediment, phytoplankton and fish species was investigated in Buriganga River, a major river of Dhaka City. Three different discharge points (Basila Bridge, Hazaribagh and Babu Bazar) were selected based on their proximity to heavy industrial discharges. Plant Enhydra fluctuans, phytoplankton Lemnoideae and fish species such as Heteropneustes fossilis, Channa striata, Corica soborna and Wallago attu of the Buriganga River were analyzed for heavy metals. Different environmental indices were determined (e.g., contamination factors, plant concentration factors, biomagnification factors, etc.), and correlations among concentrations in different compartments were obtained. Concentrations of Cr, Cd and Pb were above the toxicity reference values (TRV) for surface water quality standards applicable for aquatic life. Chromium (Cr) was found at very high levels 103 mg/kg in soil and 163 mg/kg in the plants in Hazaribagh tannery wastes discharge point. The biological samples had enough evidence for bioaccumulation of metals. Although environmental indices exhibited signs of improvement, evidence of higher level of metals in sediment, plants and fishes seemed alarming. Positive correlations among heavy metal concentrations in soil, water and plants indicate linear dependence of heavy metals accumulation from water and soil into the plants. This study emphasizes the necessity of controlling the point and nonpoint urban pollution sources discharging into the Buriganga River. [ABSTRACT FROM AUTHOR]

A comparative analysis was made on hematological, biochemical and oxidative stress indices in male spiny eel fish (Mastacembelus armatus) collected from two main rivers, the Haora and the Gomati Rivers of Tripura, a State of Northeast India, in relation to certain physiochemical properties of the waterbodies. It was revealed that total count of RBC, hematocrit, Hb, MCV and MCHC were significantly low in the Haora River fish samples. Significant differences in the biochemical variables were noted regarding tissue energy metabolism such as blood glucose level, liver and muscle glycogen contents, pyruvic acid level, free amino acid nitrogen, transaminase enzyme activities, tissue and serum protein contents, liver glucose 6-phosphatase activity and TCA cycle enzyme activities such as MDH, SDH and IDH. The water quality of the rivers was assessed in terms of pH, turbidity, total suspended solids, total dissolved solids, total alkalinity, chemical oxygen demand (COD), biochemical oxygen demand (BOD), total hardness and heavy metal/metalloid concentration such as lead, cadmium, chromium and arsenic, which revealed that the Haora River was more polluted than the Gomati River. These might be involved in deterioration of body's antioxidant defense system of the Eel fish of Haora River, as evidenced by depletion of tissue glutathione content, elevation of lipid peroxidation level and decreased antioxidant enzyme activities in the tissue samples of the studied fish. These suggested that poor water quality of the Haora River was supposed to be an important causative factor for more adverse toxicological effect on the spiny eel fish of that river. [ABSTRACT FROM AUTHOR]

This review thoroughly presents the recent progress of Deinococcus radiodurans, recombinant D. radiodurans and immobilized D. radiodurans as superior adsorbents to efficiently remove toxic heavy metals ions and radionuclides. Finally, a summary and prospect on the opportunities and challenges of D. radiodurans are provided. [ABSTRACT FROM AUTHOR]

The present study focused on the heavy metal and essential element contents that were detected in 37 different plants for making assessments to reveal possible heavy metal contamination and its effects on plant and human health. These plants having medicinal properties are used widely in the southeast part of Turkey. ICP-OES was employed for the determination of Al, B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn concentrations in the leaves of some selected medicinal plants. The concentration rates (in mg kg−1) obtained in ascending order were as in the following ranges: 8.68–278.83 for Al, 46.68–505.24 for B, 2430.0–15,561.3 for Ca, 0.04–1.11 for Cd, 0.94–21.67 for Cr, 13.7–44.81 for Cu, 12.1–456.2 for Fe, 1083.3–9026.98 for K, 344.8–3064.72 for Mg, 48.32–557.62 for Mn, 295.38–1416.02 for Na, 0.042–9.58 for Ni, 1.37–18.0 for Pb, and 68.82–220.29 for Zn. The plants collected from the sites that were located in close proximity to industrial and mining areas as well as farming fields were found to contain higher heavy metal concentrations. Our findings demonstrated that necessary precautions must be taken into consideration for saving the fields from heavy metal contamination where medicinal plants are grown or collected. Otherwise, it shows that these plants could pose risk to human health. [ABSTRACT FROM AUTHOR]

The increase of toxic concentration leads environmental pollution. Soil pollution has become the most important problem of current scenario due to the rapid growth of industries. The pollution level can be measured based on the concentration of heavy metals in soil. This work focus on the level of heavy metal concentration in Soil because of water pollution in Tirupur District, Tamilnadu, India, known for dying activities. The heavy metal concentrations have been investigated using soil samples and remote sensing data (Landsat 8 OLI images) with the relevant soil standards. Spectral mixture modelling approach and regression analysis are applied to the field and remote sensing data to map heavy metal contamination in soil. Finally, the element concentration of remote sensing data was correlated with in-situ data and results are analyzed. [ABSTRACT FROM AUTHOR]

The occurrence of arsenic (As) in groundwater (drilled well water) that were used for drinking, cooking, and personal hygiene and its risks to human health in Long An and Tien Giang provinces (Mekong delta, Vietnam) were evaluated in this study. The average As concentrations were 15.92 ± 11.4 μg/L (n = 24, Long An) and 4.95 ± 4.7 μg/L (n = 24, Tien Giang). The average concentrations of As in Long An had not reached the WHO and QCVN 01: 2009/BYT healthy drinking water standard (10 μg/L). When used as a source of water for drinking and daily activities, arsenic-contaminated groundwater may have a direct impact on human health. The risk assessment from groundwater established by the US Environmental Protection Agency (USEPA) was conducted. The risk assessment showed that the average cancer risk (CR) values were 8.68 × 10−4 (adults) and 2.39 × 10−3 (children) for Long An, and 2.70 × 10−4 (adults) and 7.43 × 10−4 (children) for Tien Giang. These results were significantly higher than the CR (1 × 10−4) proposed by the USEPA. The adverse health effect was therefore specifically warned by the use of arsenic-contaminated groundwater. This research offers valuable knowledge for efficient water management approaches to guarantee local communities' health protection. [ABSTRACT FROM AUTHOR]

In order to assess the impact of the proper functioning of wastewater treatment plants (WWTPs) and sanitation networks on the quality of water and surface sediments of the Oued Fez River and its tributaries, and ultimately their outlet in the Sebou River, physico-chemical, geochemical and mineralogical analyses were performed. The components were studied in high- and low-water regimes at eight sites. Seven heavy metals (As, Cd, Cr, Cu, Ni, Pb and Zn) were investigated in the sediments, with a decreasing trend being identified as Zn > Cu > Pb > Cr > As > Ni > Cd, and a mobility sequence as Cu > Pb > Zn > Ni > Cr. A comparison of the total heavy metal concentrations in the Oued Fez and Sebou River sediments with those of previous studies indicated a reduction in the harmful and polluting contribution of the Oued Fez to the Sebou River. The heavy metal assessment was achieved using environmental indices and sediment quality guidelines. The obtained results indicate that the presence of heavy metals in the sediment mainly comes from anthropogenic activities. Based on these results and their comparison with those from previous studies, the contribution of WWTPs and sanitation networks to improving the water quality of the middle Sebou River is clearly noteworthy. [ABSTRACT FROM AUTHOR]

Investigations of the impact of heavy metals on microbial community structure are crucial for bioremediation of the contaminated sites. To this end, high-throughput 16S rRNA sequencing was performed to assess the variations of bacterial communities in 6 heavy metal-contaminated soils sampled from Liujiaping (LJP) and Shanping (SP) lead–zinc tailings situated in northwestern China. Compared with those of the farmland soil (NT), the heavy metal levels and chemical properties of the tailing soils were significantly different. Consistently, the bacterial community structures have been changed, displaying as the bacterial richness and diversity in the tailing soils were either increased or decreased, i.e., trending as SP > NT > LJP. The relative abundances of certain bacterial phyla mainly including Actinobacteriota, Acidobacteriota, Cyanobacteria, Gemmatimonadota, and Bacteroidota were significantly increased in certain SP and/or LJP soils. Further, the relative abundances of Actinobacteriota and Bacteroidota were positively correlated with Cd, TP, TK, SOM, TN, and pH. The abundance of Cyanobacteria was significantly upregulated by Cu, Zn, and TP. Acidobacteriota was notably positively correlated with Cr, Pb, and NO3−_N. On the contrary, the relative abundance of Chloroflexi was negatively correlated with all the environmental parameters, especially with Cd, NO3−_N, TP, SOM, and TN. Together, our results implied that the heavy metals and chemical properties were both driving forces of the variations of the bacterial community structures in the tailing soils. Overall, we have successfully identified certain bacterial species such as s__unclassified_g__Sulfurifustis, s__unclassified_f__Rhodanobacteraceae, s__unclassified_g__Conexibacter, s__unclassified_g__norank_f__norank_o__Gaiellales, and s__unclassified_g__Blastococcus which were probably heavy metal-tolerant in these specific tailing soils, and this will provide a theoretical support for further bioremediations. [ABSTRACT FROM AUTHOR]

Laguna de Bay, the largest and nationally significant freshwater lake ecosystem in the Philippines, has been increasingly subjected to anthropogenic pressures over the years. Domestic, agricultural, and industrial activities in the surrounding areas have contributed directly and indirectly to the deterioration of the lake's overall ecological health and integrity. This study assessed the chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), lead (Pb), and cadmium (Cd) contamination in Asiatic clam, Corbicula fluminea, using quadrupole inductively coupled plasma–mass spectrometry. Estimated daily consumption of Asiatic clam was determined through a social survey. The data from analytical analysis and social surveys were utilized to calculate the target hazard quotient (THQ) to determine the potential health risks of consuming heavy metal–enriched clams to fishing households. Results from the Knowledge, Attitude, and Practices (KAP) survey indicated that the majority of the respondents have an acceptable level of knowledge on the hazards posed by the intake of contaminated clams but disapproved the banning of its collection and consumption. Sampled households with high consumption rates in all municipalities except Victoria were also found to be exposed to imminent health risk due to the high toxicity level of As based on their THQ values. Overall, one-third of the fishing households exposed to elevated health risk based on their total target hazard quotient (TTHQ) values already warrant a concern. The potential human health risks validate the worsening condition of Laguna de Bay. Integrative and holistic management of the lake through collaborative efforts of various stakeholders and institutions is necessary, to restore the health of the ecosystem and safeguard the health of the public. [ABSTRACT FROM AUTHOR]

Background: The use of metal-containing and antimicrobial compounds is a common practice in aquaculture operations in Nigeria. Only a few studies have focused on the impact of these chemicals on metal and antibiotic resistance development in the bacterial flora of aquaculture. This study therefore sets out to fill this gap. Results: Five metals, namely copper (Cu), zinc (Zn), lead (Pb), nickel (Ni) and chromium (Cr), were detected at different concentrations in the pond water samples, with most values obtained exceeding the maximum recommended national standard for fisheries and recreation water quality criteria set by the National Environmental Standards and Regulations Enforcement Agency (NESREA) in Nigeria. A total of 121 Vibrio spp. were recovered from the aquaculture pond water with Vibrio cholerae having the highest frequency (37) followed by Vibrio parahaemolyticus (36), Vibrio vulnificus (36) and Vibrio alginolyticus (12). Seventy-five isolates were recovered from ponds with history of antibiotic use, while the ponds with no recognized history of antibiotic use had forty-six isolates. The percentage resistance to antibiotics in the isolates was: ampicillin (88.5%), amoxicillin–clavulanate (44.3%), tetracycline (41%), trimethoprim-sulfamethoxazole (22.1%), chloramphenicol (15.6%), ciprofloxacin (11.5%), imipenem (5.7%), ceftazidime (4.1%) and gentamicin (0%). All the isolates tolerated all the metals to 400 µg/mL concentration while only the trio of Pb, Ni and Cr were tolerated beyond the concentration. Zn and Cu appeared to be the most toxic metals on Vibrio spp., with no isolate surviving beyond the 400 µg/mL concentration mark, while 57 of the 121 isolates survived Cr at the highest concentration (3200 µg/mL), making it the most tolerated of the metals. Conclusion: This study reports a high level of metal contamination in the aquaculture ponds studied. The concentration of the metals exceeded the maximum permissible limits in Nigeria. Also, there was coexistence of metal and antibiotic resistance in the bacteria recovered from the aquaculture ponds. There is a need to regulate the use of chemicals, especially antibiotics and some biocidal compounds, to clamp down on the introduction of metals and antibiotics into the aquaculture systems, as these chemicals could facilitate the development of resistance traits in aquaculture bacteria by creating a selective pressure in the aquaculture environment. [ABSTRACT FROM AUTHOR]

Herbal medicines have been reported to contain many contaminants that are potential harmful to health. These include heavy metals, such as lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg). Therefore, this study aimed to measure the levels of Pb, Cd, As, and Hg in several orally administered herbal products available in the Iranian market. Fifteen products labeled (A-O) of different brands from three different production batches (n = 45) were purchased from traditional herbal medicine factories in Iran. Each sample was digested with nitric acid by the wet digestion method, and the resultant solutions were used to determine the concentrations of Pb, Cd, As, and Hg. These measurements were performed using flame atomic absorption spectrometry, graphite furnace atomic absorption, or cold vapor atomic absorption. The lead, cadmium, arsenic, and mercury contents in the investigated samples did not show significant levels that may be associated with toxicity. All four metals were present at concentrations below the limits recommended by the WHO (World Health Organization), American Herbal Products Association (AHPA), and Canadian standard, but in several herbal products, the concentrations of these trace elements exceeded the Agency for Toxic Substances and Disease Registry (ATSDR). The concentrations of Pb, Cd, As, and Hg in commercially available herbal remedies were well below the acceptable intake recommended by global recommendations. Our findings revealed that at present, the amount of heavy metals in medicinal herbs processed at the level of supply by pharmacies licensed is favorable. [ABSTRACT FROM AUTHOR]

The concentrations of major and trace elements in the sediments from the Four River inlets of Dongting Lake were analysed. The results show that the element compositions of the Four River inlet sediments are different, among which higher amounts of Al2O3, Fe2O3, MnO, Cs, Rb, Th, U, Y, and REE are found, while MgO, CaO, Na2O, and Sr are more depleted in the sediments from the Xiangjiang and Zijiang inlets than in the sediments from the Yuanjiang and Lishui inlets. The Xiangjiang inlet sediments are distinctly higher enriched (EF > 5.0) in heavy metals Bi, Cd, Mn, Cu, Pb, and Zn, while the other river sediments are moderately enriched (EF > 2.0) in these heavy metals. These geochemical differences are resulted from the source lithology, chemical weathering, hydrological sorting, and anthropogenic processes taking place in the watersheds. The principal component analysis and the geochemical vertical profiles suggest that the trace metals Ba, Mo, V, Cr, Co, Ni, Cs, Rb, Sc, Th, U, Ga, Ge, Zr, Hf, Ta, Nb, and REE are of terrigenous sources. The heavy metals including Bi, Cd, Mn, Cu, Pb, and Zn in the sediments can include those contributed by anthropogenic processes, such as mining and smelting of Pb-Zn ores. Therefore, presenting a scheme for the geochemical backgrounds of the watershed is recommended here for future assessment of the heavy metal contamination in sediments of the watershed. [ABSTRACT FROM AUTHOR]

Tarabalo geothermal area is one of the eight geothermal areas existing in the Indian state of Odisha. The present study aims to (i) understand the influence of thermal spring water and agricultural activities on the spatial distribution of trace elements in the soil, (ii) delineate the contamination of heavy metals, and (iii) identify the possible sources of trace elements in the soil. For these purposes, thermal spring water samples were collected from 9 locations and twenty soil samples were collected in a gridded pattern from the geothermal area. Trace elements such as As, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Pb, Sb, Se, Th, Tl, U, V, and Zn are considered in this study. The trace element concentrations in the soil show wide variation ranging from 0.02 (Be) to 931.4 mg/kg (Mn). The contribution from thermal spring water is considered to have a limited effect on the accumulation and distribution of trace elements. The values obtained from Igeo, EF, and ERF to delineate contamination of heavy metals in the soil show that it is enriched with heavy metals such as As and Pb. Based on ERI values, the ecological risk caused by the concentration of heavy metals in the study area is low. Trace element concentrations in the soil are considered to be significantly from geogenic source and moderately from anthropogenic activities. [ABSTRACT FROM AUTHOR]

This study focuses on heavy metal contamination in soils due to recreational shooting within the Tonto National Forest, Arizona. The main research questions are: (1) Have some soils within the Tonto National Forest (NF) been contaminated with lead (Pb) due to recreational shooting? (2) How far downslope have the soils been contaminated? Soils in permitted shooting areas were tested for lead (Pb), which show statistically significant differences in mean concentration levels when compared to control sites. The dry weight of mean lead concentrations (5125 mg/kg; p value < 0.005) were 152 times greater than that of the respective uncontaminated control site (33.4 mg/kg). Lead contamination ranged from 25,482 to 7185 mg/kg approximately 9.3 m downslope and gradually decreased from there, but was still contaminated over the entire length of the hillslope. To my knowledge, this is the first known study to examine heavy metal contamination in surficial soils within the Tonto NF due to recreational shooting. [ABSTRACT FROM AUTHOR]

In this study, two amendments, poultry waste and ammonium nitrate, were evaluated to condition and stabilize a mine tailing and thus help the vegetation cover settle. Individually, ammonium nitrate was tested as a nitrogen source and chicken bone ash as a phosphate source. For this, laboratory tests were made on soil columns from the area to be remediated. The mobility and availability of metals and nutrients were determined by analyzing their leachates chemically. The results showed that the use of chicken bone ash decreases soluble metal concentrations, particularly in Fe and soluble Mn. On the other hand, experimental conditions proved that the acidification produced by ammonium nitrate nitrification does not significantly increase the lechate metal content. Therefore, its use for fertilization does not involve phytotoxicity risks. Regarding the availability of macronutrients as well as trace elements, the results showed that the concentrations lie within the ranges suitable for plant nutrition. So, the treatments are effective both for fertilization and phytoremediation. [ABSTRACT FROM AUTHOR]

Purpose: This work deals with the application of a solidification/stabilization process with the aim to obtain safe and reusable granular materials from a polluted soil and to elucidate the mechanisms involved in the retention of several heavy metals. Materials and methods: The High Performance Solidification/Stabilization (HPSS®) process was applied to the selected contaminated soil by using both ordinary Portland cement and calcium aluminate cement, as well as several binders prepared by combining these two types of cement in different proportions. Leaching and mechanical tests were carried out to evaluate the performances of the proposed binders in the pellets produced by the HPSS® process, while XRD analysis and SEM/EDX imaging were used to investigate the phase composition and internal microstructure of the treated samples. Result and discussion: The examination of the obtained granular materials revealed that the immobilization of Sb was mainly related to its inclusion within calcium silicate hydrates' structure; the immobilization of Cr, Pb, Ni, Co, Zn and Tl was associated with the eluate pH and their incorporation within ettringite structure, while for Se, Cu, Ba and V, the main retention mechanism was physical encapsulation. In addition, the application of a wet conditioning process improved the materials' performance, leading to granules always satisfying the Italian regulatory requirements for reuse. Conclusions: The findings obtained in this study were useful to better elucidate the mechanisms involved in the retention of heavy metals by several binders, contributing to the development of sustainable management strategies for contaminated soils and sediments through their transformation into reusable materials. [ABSTRACT FROM AUTHOR]