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As an alternative fuel, bio-waste coconut shells have shown promise in reducing pollution during the co-combustion process. In this study, a novel metal-mineral adsorbent, Ca-Al (Ca 5 Al 6 O 14), was prepared and physically (ultrasonic) and chemically (ethylene glycol) modified to enhance its adsorption properties. Thermal adsorption experiments investigated the effect of the adsorbents on the fixation of six heavy metals (HMs): Cr, Cu, Mn, Ni, Pb, and Zn. XRD, SEM, BET, and XPS were used to analyze the adsorbents and the adsorption mechanism was investigated by combining lattice oxygen concentration and Factsage simulation calculations. The ecological risk assessment of heavy metals was used to comprehensively evaluate the fixation effects of the three Ca-Al adsorbents at different additive levels. The results showed that the modification significantly changed the morphological characteristics and oxygen activity of the Ca-Al adsorbents, increased the lattice oxygen and chemisorbed oxygen concentration, and laid the foundation for promoting the chemisorption process in the fixation of heavy metals. In combination with the E r (environmental risk factors), adding all three adsorbents reduced R i (Risk index). Among them, Ca-Al (EG) at 3% had the best effect on R i. 3% Ca–Al (EG) reduced the E r value of Ni by 49.02%. 5% Ca–Al (EG) reduced the E r value of Cr by 86.01%. 5% Ca–Al (UM) had the best effect on Mn, with a reduction of 46.13%. The addition of 10% Ca–Al (UM) reduced E r of Ni by 50.43%. Considering the practical application in coal-fired power plants, Ca-Al(EG), which exhibits a higher fixation rate at small additions, is more suitable. [Display omitted] • The effect of Ca-Al adsorbent and modified Ca-Al adsorbent was investigated. • Combining experiments with Factsage simulations to explore reaction mechanisms. • Investigation of modified enhanced adsorption mechanism in combination with XPS. • Environmental risk factors evaluated the performance of the adsorbent. [ABSTRACT FROM AUTHOR]

The effectiveness of bioretention cells for heavy metals (HMs) and microplastics (MPs) removal from stormwater runoff has been demonstrated. Knowledge of the mechanisms that dictate the interactions between MPs and HMs would be helpful in pollution control. In this study, the performances of different water-soil-plant bioretention cells for HMs removal through the interception of polyethylene MPs (PE-MPs) were investigated. The results showed that PE-MPs bound to HMs and preferentially tended to bind to Pb (32%–44%) in the complex HMs (Cu, Zn, Cd, and Pb). This could be the reason that the concentration of Pb significantly increased in the effluent under low-intensity simulated rainfall events over a long duration. The accumulation of 1.49 g/kg PE-MPs caused a significant soil pH value decrease and a notable soil zeta potential increase in the bioretention cell, while the low sand/silt ratio media buffered this process. The retention of PE-MPs increased 138.5% in the 0–10 cm soil surface layer when the sand/silt ratio reduced from 2:1 to 1:1 and planted with Canna indica. Meanwhile, PE-MPs amplified the instability of Zn removal in bioretention cells under low-intensity rainfall events in long-duration, high silt percentage substrate and vegetation coverage. The study would contribute to developing a long-term management program for PE-MPs and HMs trapped in bioretention cells to reduce the risk of pollution transport. [Display omitted] • The water-soil-plant system is crucial for removing PE MPs and HMs. • PE-MPs reduce pH value and increases Zeta potential in soil. • PE-MPs negatively impact the removal efficiency of HMs. • Rainfall intensity and antecedent drying duration significantly affect HMs removal. • Low sand/silt ratio and vegetation coverage benefit PE-MP retention. [ABSTRACT FROM AUTHOR]

Microplastics, pervasive contaminants from plastic, present significant challenges to wastewater treatment processes. This review critically examines the interactions between microplastics and biofilm-based treatment technologies, specifically focusing on the concepts of "biofilm on microplastics" and "microplastics in biofilm". It discusses the implications of these interactions in contaminant removal and process performance. Advanced characterization techniques, including morphological characterization, chemical composition analysis, and bio-information analysis, are assessed to elucidate the complex interplay between microplastics and biofilms within biofilters, biological aerated filters (BAFs), rotating biological contactors (RBCs), and moving bed biofilm reactors (MBBRs). This review synthesizes current research findings, highlighting that microplastics can either hinder or enhance the treatment processes, contingent on their concentration, physicochemical properties, and the specific biofilm technology employed. The insights gained from this review are essential for developing strategies to mitigate the adverse effects of microplastics and for optimizing the design and operation of wastewater treatment. [Display omitted] • Relationship between microplastics and biofilm in treatment processes is discussed. • Biofilm on microplastics enhances uptake of heavy metals and organic contaminants. • Microplastic removal in biofilm reactors significantly depends on the particle size. • Backwashing may release immobilized microplastics from the main biofilm. • Microplastics can hinder or enhance the treatment depending on various factors. [ABSTRACT FROM AUTHOR]

In this article, a multivariate analysis of the parameters determining the transport and fate of selected heavy metals in the water - bottom sediment interface was carried out. The studies were carried out in the summer season of 2019 at Nielisz Reservoir (southeastern Poland, Lublin Voivodeship). Finally, a previously unknown factor related to the quality of organic matter was identified. Autochthonous organic matter was shown to promote the accumulation of the studied heavy metals. To date, the significance of the origin of organic matter in the context of the transport and fate of heavy metals in retention reservoirs has rarely been reported in the scientific literature. More than that, this factor was not considered an important component in the process of heavy metal deposition in bottom sediments. However, it turns out that not only the quantity of organic matter, but also its quality plays an important role in the circulation of heavy metals in retention reservoir ecosystems. It was found that autochthonous organic matter promotes the accumulation of the studied heavy metals. It can be assumed that, in a sense, it plays the role of a catenary ("hub") controlling the fate of heavy metals in the water-sediment system. It has also been conjectured that, in a sense, OM S may reflect the potential for heavy metal assimilation by aquatic vascular plants (mainly of the C3 group). Plants with a photosynthetic pathway similar to the C3 group generally have a much lower enrichment in the 13C isotope (δ13C from −38‰ to −22‰). In our case, the lowest δ13C-TOC S value was −24.05‰, and the average for the whole reservoir was −21.53‰. In addition, it was observed that quantitative changes in the isotopic composition of total organic carbon δ13C-TOC S , corresponded with changes in the content of the heavy metals studied in entrapped sediments. [Display omitted] • The quality of organic matter plays a key role in the fate of heavy metals. • Autochthonous organic matter promotes the accumulation of heavy metals. • With the depletion of the carbon isotope 13C, the heavy metal content increases. [ABSTRACT FROM AUTHOR]

Utilizing plant extracts for soil washing is a promising and cost-efficient strategy to permanently remove toxic metals from farmland soils. However, the efficiency of current plant extracts in heavy metals removal is constrained by the need of excessively high liquid-solid ratios (>10:1), which limits their practical application in the farmland soils. To address this challenge, we developed a novel binary washing agent consisting of Fructus mume residue extract (RPM) and methylglycinediacetate acid (MGDA). Through optimization experiments, we determined an optimal composition of 50 g L−1 RPM and 0.34 g L−1 MGDA (RPMG3), which exhibited a remarkable synergistic effect on the removal of Cd and Cu from two polluted farmland soils. Compared to the single use of RPM or MGDA, RPMG3 increased metal removal efficiency by 44.6%–303.8% in the alkaline dryland soil and 55.8%–141.9% in the slightly acidic paddy soil, at an optimum liquid-solid ratio of 2:1. The contents of soil Cd and Cu can be reduced to below the risk screening values via acid activation, metal ion exchange, and complexation of functional groups. Moreover, the potential ecological risks associated with Cd in the soils were significantly mitigated due to the decrease in exchangeable and reducible Cd fractions following RPMG3 washing. Additionally, RPM and RPMG3 washing led to enhancements in soil organic carbon and nutrient concentrations, as well as increased activities of soil enzymes including catalase, urease, and β-glucosidase. Notably, RPMG3 washing exhibited the most pronounced promotion effect on wheat seed germination and growth. Taken together, the binary complex of RPMG3 demonstrates potential as an environmentally friendly green washing agent capable of in reducing heavy metals from farmland soil with great efficiency, even at low liquid-solid ratios. [Display omitted] • RPMG3 (complex of Fructus Mume and MGDA) exhibited synergistic effects on soil metal removal. • The formation of new hydroxyl and amine groups in RPMG3 promoted soil metal removal. • RPMG3 washing reduced the potential risk of Cd and Cu and replenished soil nutrients. • RPMG3 washing most significantly promoted wheat seed germination and growth. • RPMG3 was a feasible washing agent for Cd and Cu removal under low L/S ratios. [ABSTRACT FROM AUTHOR]

Determining the distribution trends, transport mechanisms, and ecological risks of heavy metals (HMs) in urban river sediments is essential for the government to conduct appropriate remediation work. In this study, we collected sediment cores from the Yayao Waterway in Foshan City, China. The vertical distribution profiles of dissolved and labile Fe, Mn, Cd, Zn, Cu, Cr, Ni, Pb, As, and Co in the sediments were obtained using the thin-film diffusive gradient (DGT) and high-resolution peeper (HR-Peeper) techniques. In addition, the transport rates, contamination levels, and ecological concerns of the HMs were evaluated using the European Community Bureau of Reference (BCR) sequential extraction technique, the DGT-induced sediment fluxes (DIFS) model, and multiple contamination evaluation metrics. The results showed that most of the DGT-labile HMs were associated with Fe/Mn (hydrogen) oxides, and in particular, Zn, Ni, and Cr showed a significant negative correlation with Fe/Mn (p < 0.001). Additionally, Cd had the highest bioavailability (89.17%), and its net diffusive flux at the sediment–water interface (SWI) was positive, which indicated a high release risk from the sediment. However, the R-value of Cd based on the DGT-induced sediment fluxes (DIFS) operation was extremely low, suggesting that although Cd had the biggest supply pool of releases, its release rate was slow. The majority of sampling sites had significantly higher total HM contents in the surface sediments than the background values. The HM contamination in the sediments originated from human activities, primarily from industrial enterprises and with a large contribution from both agricultural and domestic sources. The most polluted HM with the highest ecological danger was Cd, followed by Cu, Zn, Ni, and As when the results of the four pollution evaluation indicators were combined. Consequently, the risk of contamination by HMs in inner-city river sediments should receive more attention. [Display omitted] • The high-resolution profiles of labile and dissolved HMs in sediments were tested. • Fe/Mn (hydrogen) oxides were recognized as vital drivers of the release of HMs. • HM pollution primarily originated from industrial sources. • The most contaminated and ecologically dangerous element was Cd. [ABSTRACT FROM AUTHOR]

Mercury, a toxic metal released by various human activities, exerts environmental stress through its bioaccumulation and biomagnification, particularly in marine habitats. South American fur seals (Arctocephalus australis) and sea lions (Otaria flavescens) reproduce on the Atlantic coast of Uruguay. As top predators, they can accumulate toxic levels of mercury and are often used as sentinel species for monitoring ecosystem health. Fur seals prey on pelagic species, such as fish and squid, while sea lions consume coastal-benthic prey. We analyzed the total mercury concentration (THg) in hair and the trophic habits (δ13C and δ15N) of females from both species. The average THg concentration in adult female sea lions (30.5 ± 9.3 μg/g dry weight) was significantly higher than in fur seals (6.3 ± 2.5 μg/g dry weight). Additionally, the mean δ15N and δ13C values were significantly higher in sea lion (δ15N: 19.2 ± 0.6‰, δ13C: −13.8 ± 0.2‰) compared to fur seals (δ15N: 16.5 ± 0.5‰, δ13C: −15.5 ± 0.6‰). Our results suggest that different trophic levels and feedings areas affect the THg concentration in Uruguayan Otariids. Notably, at the intraspecific level, the THg concentration in sea lions increased with δ13C values, suggesting a link to coastal feeding habits. This indicates that coastal feeding behaviors, compared to feeding in pelagic environments, enhance mercury bioaccumulation in Otariids along the Uruguayan coast, with the discharge of freshwater from the Río de la Plata (one of the largest estuaries in South America) basin identified as a potential mercury source. THg concentrations found in female sea lion hair are the highest reported in Otariids globally. Mercury levels exceeded toxic thresholds observed in other mammals and could pose significant health risks. Our findings may explain why sea lions were particularly affected by the avian influenza outbreak in Uruguay compared to fur seals. Monitoring the declining sea lion population is crucial, making our results significant for integrated conservation and management strategies. [Display omitted] • Marine mammals are good sentinel species for monitoring Hg bioaccumulation. • Fur seals and sea lions prey on pelagic and coastal benthic species, respectively. • Hg accumulation in the hair of female sea lions was higher than in fur seals. • Hg levels in individual female sea lions rose with δ13C, indicating a link to coastal feeding habits. [ABSTRACT FROM AUTHOR]

Antimicrobial resistant bacteria can occur in the primary food production environment. The emergence and dissemination of antimicrobial resistance (AMR) in the environment can be influenced by several factors, including the presence of heavy metals. The aim of this study was to examine the presence and characteristics of antimicrobial resistant Enterobacterales in soils and spinach grown in soils with and without zinc amendment. A total of 160 samples (92 soil and 68 spinach) were collected from two locations, in which some plots had been amended with zinc. Samples were cultured on selective agars for detection of extended-spectrum beta-lactamase-producing Enterobacterales (ESBL), carbapenem-resistant Enterobacterales and ciprofloxacin-resistant Enterobacterales. Samples were also cultured for enumeration of total Enterobacterales. Isolates were identified by MALDI-TOF. Antimicrobial susceptibility testing was carried out in accordance with EUCAST and CLSI criteria. The whole genome sequence (WGS) of selected isolates was determined. Inductively coupled plasma atomic emission spectrometry was also performed on soil samples in order to measure the concentration of zinc. In total 20 antimicrobial resistant Enterobacterales were isolated from the soil (n = 8) and spinach samples (n = 12). In both sample types, Serratia fonticola (n = 16) was the dominant species, followed by Escherichia coli (n = 1), Citrobacter freundii (n = 1) and Morganella morganii (n = 1) detected in spinach samples, and Enterobacter cloacae (n = 1) detected in a soil sample. The WGS identified genes conferring resistance to different antimicrobials in agreement with the phenotypic results; 14 S. fonticola isolates were confirmed as ESBL producers and harboured the bla FONA gene. Genes that encoded for zinc resistance and multidrug efflux pumps, transporters that can target both antimicrobials and heavy metals, were also identified. Overall, the findings of this study suggest the presence of zinc did not influence the AMR Enterobacterales in soil or spinach samples. [Display omitted] • Zinc impact on AMR isolates was examined in soil and spinach samples. • Phenotypic and genotypic profiles of AMR Enterobacterales were characterized. • No evidence of zinc impact on AMR Enterobacterales was observed. • Primary food production environment can harbour clinical relevant AMR bacteria. [ABSTRACT FROM AUTHOR]

Exposure to environmental heavy metals may pose a risk factor for developing preeclampsia (PE) modified through intervention. This case-control study aimed to investigate the association between serum heavy metal concentrations and PE in pregnant women and whether hormones served as mediating factors in the impact of heavy metals on PE. From October 2020 to 2022, 160 patients with PE and 160 pregnant women with normal deliveries were recruited at Dongguan Songshan Lake Central Hospital. Serum concentrations of manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), lead (Pb), β- human chorionic gonadotropin (β- hCG), progesterone (P), estradiol (E2), testosterone (T), cortisol (Cort), and cortisone (Cor) were measured. Logistic, restricted cubic splines, weighted quantile sum and multivariate linear regression models were employed to account for different aspects and explore the relationships among heavy metals, hormones, and PE. Mediation model analysis was performed to assess the role of hormones in mediation. The median concentrations of Mn, E2, and Cort were lower in the PE group than in the control group. The median concentrations of Cu, Zn, β- hCG, and T were higher in the PE than in the control. Mn, E2, and Cort showed negative associations with PE, while Cu, Zn, β- hCG, and T demonstrated positive associations, as determined through logistic regression. Mn, Cu, and Zn displayed linear dose-response relationships with PE. Zn and Cu had high weights in the positive association model of mixed heavy metal exposure with PE. The mediation analysis revealed that serum E2, P, T, Cort, and Cort/Cor might be potential mediators of the association between heavy metals (Mn, Cu, and Zn) and PE. [Display omitted] • Restricted cubic splines and weighted quantile sum regression were used. • Serum Cu, Zn, and Cd were positively associated with preeclampsia. • Serum Mn was negatively associated with preeclampsia. • Serum hormones might mediate the association between heavy metals and preeclampsia. [ABSTRACT FROM AUTHOR]

Exploration of the association between heavy metal bioaccessibility (BAc) and soil properties is essential for rationalization of risk assessment and remediation of contaminated soil; however, the high complexity of soil systems often yield conflicting outcomes. To avoid erroneous conclusions, individual comparisons of soil properties is essential. Herein, we determined the changes in the BAc of Pb and Cu with the variation in soil pH and SOC content using Unified Bioaccessibility Research Group of Europe method, and validated these findings with in vivo mouse bioassays. Results indicated that the BAc of Pb and Cu in gastric and intestinal phases decreased by 1.76%–3.92% and 0.90%–3.27%, and by 0.41%–6.01% and 0.67%–1.59%, respectively, with every unit increase in soil pH. Furthermore, with every 1% increase in the absolute content of SOC, the BAc of Pb and Cu decreased by 4.04%–13.94% and 4.01%–34.7%, and by 8.98%–30.15% and 9.58%–20.03%, respectively. The in vivo bioassays results confirmed decrease in Pb concentrations in the liver, kidney, and blood of mice with the increase in Ferralosol pH and SOC content. These findings revealed that the health risks associated with accidental exposures to Pb- and Cu-contaminated soils with high pH and SOC level were relatively low, and the consistent in vivo and in vitro results for the BAc of Pb and Cu suggest the requirement for a swift and simple approach for assessing the risks of heavy metal contaminated soils. Thus, this study enhanced our understanding of the variations in risk assessments with soil properties of Pb- and Cu-contaminated soils, highlighting the role of soil characteristics in health risk assessment and remediation of contaminated soils. [Display omitted] • Pb and Cu bioaccessibility decreased with increasing soil pH and SOC. • Acid-soluble metal transformed to reducible, leading to decreasing bioaccessibility. • In vivo bioassay showed a reduction in Pb-absorption with increasing pH and SOC. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) have aroused growing environmental concerns due to their biotoxicity and vital roles in accelerating the spread of toxic elements. Illuminating the interactions between MPs and heavy metals (HMs) is crucial for understanding the transport and fate of HM-loaded MPs in specific environmentally relevant scenarios. Herein, the adsorption of copper (Cu2+) and zinc (Zn2+) ions over polyethylene (PE) and polyethylene terephthalate (PET) particulates before and after heat persulfate oxidation (HPO) treatment was comprehensively evaluated in simulated and real swine wastewaters. The effects of intrinsic properties (i.e., degree of weathering, size, type) of MPs and environmental factors (i.e., pH, ionic strength, and co-occurring species) on adsorption were investigated thoroughly. It was observed that HPO treatment expedites the fragmentation of pristine MPs, and renders MPs with a variety of oxygen-rich functional groups, which are likely to act as new active sites for binding both HMs. The adsorption of both HMs is pH- and ionic strength-dependent at a pH of 4–6. Co-occurring species such as humic acid (HA) and tetracycline (TC) appear to enhance the affinity of both aged MPs for Cu2+ and Zn2+ ions via bridging complexation. However, co-occurring nutrient species (e.g., phosphate and ammonia) demonstrate different impacts on the adsorption, improving uptake of Cu2+ by precipitation while lowering affinity for Zn2+ owing to the formation of soluble zinc-ammonia complex. Spectroscopic analysis indicates that the dominant adsorption mechanism mainly involves electrostatic interactions and surface complexation. These findings provided fundamental insights into the interactions between aged MPs and HMs in swine wastewaters and might be extended to other nutrient-rich wastewaters. [Display omitted] • Heat persulfate oxidation treatment accelerates the fragmentation of pristine MPs. • HPO treatment endows pristine MPs with a variety of oxygen-containing groups. • Weathering time and size of MPs greatly affect their affinity toward Cu2+ and Zn2+. • Aged PE prefers to adsorb Zn2+ while aged PET prefers to capture Cu2+. • Humic acid and tetracycline enhance the adsorption of HMs by bridging complexation. [ABSTRACT FROM AUTHOR]

Understanding the interaction between heavy metals and soil microbiomes is essential for maintaining ecosystem health and functionality in the face of persistent human-induced challenges. This study investigated the complex relationships between heavy metal contamination and the functional characteristics of soil microbial communities in the tidal soils of Hangzhou Bay, a region experiencing substantial environmental pressure due to its proximity to densely populated and industrialized regions. The north-shore sampling site showed moderate contaminations (mg/kg) of total arsenic (16.61 ± 1.13), cadmium (0.3 ± 0.05), copper (31.28 ± 1.23), nickel (37.44 ± 2.74), lead (34.29 ± 5.99), and zinc (120.8 ± 5.96), which are 1.29–2.94 times higher than the geochemical background values in Hangzhou Bay and adjacent areas. In contrast, the south-shore sampling site showed slightly higher levels of total arsenic (13.76 ± 1.35) and cadmium (0.13 ± 0.02) than the background values. Utilizing metagenomic sequencing, we decoded microbial functional genes essential for nitrogen, phosphorus, sulfur, and methane biogeochemical cycles. Although soil available nickel content was relatively low at 1 mg/kg, it exhibited strong associations with diverse microbial genes and biogeochemical pathways. Four key genes— hxlB , glpX , opd , and phny —emerged as pivotal players in the interactions with available nickel, suggesting the adaptability of microbial metabolic responses to heavy metal. Additionally, microbial genera such as Gemmatimonas and Ilumatobacter , which harbored diverse functional genes, demonstrated potential interactions with soil nickel. These findings highlight the importance of understanding heavy metal-soil microbiome dynamics for effective environmental management strategies in the tidal soils of Hangzhou Bay, with the goal of preserving ecosystem health and functionality amidst ongoing anthropogenic challenges. [Display omitted] • Heavy metals affect microbial genes involved in biogeochemical cycles in the tidal soils. • Soil available Ni highlights its interactions with soil microbiome. • Gemmatimonas and Ilumatobacter genera harbor diverse functional genes interacting with soil Ni. [ABSTRACT FROM AUTHOR]

The escalating presence of microplastics and heavy metals in marine environments significantly jeopardizes ecological stability and human health. Despite this, research on the combined effects of microplastics/nanoplastics (MPs/NPs) and heavy metals on marine organisms remains limited. This study evaluated the impact of two sizes of polystyrene beads (approximately 2 μm and 200 nm) combined with cadmium (Cd) on the ciliate species Euplotes vannus. Results demonstrated that co-exposure of MPs/NPs and Cd markedly elevated reactive oxygen species (ROS) levels in ciliates while impairing antioxidant enzyme activities, thus enhancing oxidative damage and significantly reducing carbon biomass in ciliates. Transcriptomic profiling indicated that co-exposure of MPs/NPs and Cd potentially caused severe DNA damage and protein oxidation, as evidenced by numerous differentially expressed genes (DEGs) associated with mismatch repair, DNA replication, and proteasome function. Integrated transcriptomic and metabolomic analysis revealed that DEGs and differentially accumulated metabolites (DAMs) were significantly enriched in the TCA cycle, glycolysis, tryptophan metabolism, and glutathione metabolism. This suggests that co-exposure of MPs/NPs and Cd may reduce ciliate abundance and carbon biomass by inhibiting energy metabolism and antioxidant pathways. Additionally, compared to MPs, the co-exposure of NPs and Cd exhibited more severe negative effects due to the larger specific surface area of NPs, which can carry more Cd. These findings provide novel insights into the toxic effects of MPs/NPs and heavy metals on protozoan ciliates, offering foundational data for assessing the ecological risks of heavy metals exacerbated by MPs/NPs. [Display omitted] • MPs/NPs can serve as carriers for transporting Cd and increasing its toxicity. • Co-exposure to MPs/NPs and Cd led to a notable decline in ciliate carbon biomass. • Ciliates treated with MPs/NPs and Cd developed severe oxidative stress response. • Co-exposure to MPs/NPs and Cd caused transcriptomic and metabolomic disorders. • Co-exposure to NPs and Cd had more severe adverse effects than MPs with Cd. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) have the potential to adsorb heavy metals (HMs), resulting in a combined pollution threat in aquatic and terrestrial environments. However, due to the complexity of MP/HM properties and experimental conditions, research on the adsorption of HMs onto MPs often yields inconsistent findings. To address this issue, we conducted a comprehensive meta-analysis assisted with machine learning by analyzing a dataset comprising 3340 records from 134 references. The results indicated that polyamide (PA) (ES = −1.26) exhibited the highest adsorption capacity for commonly studied HMs (such as Pb, Cd, Cu, and Cr), which can be primarily attributed to the presence of C=O and N–H groups. In contrast, polyvinyl chloride (PVC) demonstrated a lower adsorption capacity, but the strongest adsorption strength resulting from the halogen atom on its surface. In terms of HMs, metal cations were more readily adsorbed by MPs compared with metalloids and metal oxyanions, with Pb (ES = −0.78) exhibiting the most significant adsorption. As the pH and temperature increased, the adsorption of HMs initially increased and subsequently decreased. Using a random forest model, we accurately predicted the adsorption capacity of MPs based on MP/HM properties and experimental conditions. The main factors affecting HM adsorption onto MPs were HM and MP concentrations, specific surface area of MP, and pH. Additionally, surface complexation and electrostatic interaction were the predominant mechanisms in the adsorption of Pb and Cd, with surface functional groups being the primary factors affecting the mechanism of MPs. These findings provide a quantitative summary of the interactions between MPs and HMs, contributing to our understanding of the environmental behavior and ecological risks associated with their correlation. [Display omitted] • The effects of MP/HM properties and experimental conditions were clarified. • Random forest could predict adsorption capacity and determine key affecting factors. • MP/HM concentration, SSA of MP, and pH notably affected HM adsorption onto MP. • Complexation and electrostatic interaction were involved in most MP-HM adsorption. [ABSTRACT FROM AUTHOR]

Heavy metal pollution can have adverse impacts on microorganisms, plants and even human health. To date, the impact of heavy metals on bacteria in farmland has yielded poor attention, and there is a paucity of knowledge on the impact of land type on bacteria in mining area with heavy metal pollution. Around a metal-contaminated mining area, two soil depths in three types of farmlands were selected to explore the composition and function of bacteria and their correlations with the types and contents of heavy metals. The compositions and functions of bacterial communities at the three different agricultural sites were disparate to a certain extent. Some metabolic functions of bacterial community in the paddy field were up-regulated compared with those at other site. These results observed around mining area were different from those previously reported in conventional farmlands. In addition, bacterial community composition in the top soils was relatively complex, while in the deep soils it became more unitary and extracellular functional genes got enriched. Meanwhile, heavy metal pollution may stimulate the enrichment of certain bacteria to protect plants from damage. This finding may aid in understanding the indirect effect of metal contamination on plants and thus putting forward feasible strategies for the remediation of metal-contaminated sites. This was the first study to comprehensively explore the influence of heavy metal pollution on the soil bacterial communities and metabolic potentials in different agricultural land types and soil depths around a mining area. [Display omitted] • The screening effects on soil bacteria community composition and function depend on farmland type. • The top soil bacterial community was more easily affected by tillage activities. • Low concentrations of heavy metals promoted some bacterial species and functional genes. • Some bacteria may help plants resist heavy metal pollution. [ABSTRACT FROM AUTHOR]

The disorderly discharge of industrial wastewater containing heavy metals has caused serious water pollution and ecological environmental risks, ultimately threatening human life and health. Biological treatment methods have obvious advantages, but the existing microorganisms exhibit issues such as poor resistance, adaptability, colonization ability, and low activity. However, a wide variety of microorganisms in deep-sea hydrothermal vent areas are tolerant to heavy metals, possessing the potential for efficient treatment of heavy metal wastewater. Based on this, the study obtained a group of deep-sea microbial communities dominated by Burkholderia-Caballeronia-Paraburkholderia through shake flask experiments from the sediments of deep-sea hydrothermal vents, which can simultaneously achieve the synchronous removal of vanadium and cadmium heavy metals through bioreduction, biosorption, and biomineralization. Through SEM-EDS, XRD, XPS, and FT-IR analyses, it was found that V(V) was reduced to V(IV) through a reduction process and subsequently precipitated. Glucose oxidation accelerated this process. Cd(II) underwent biomineralization to form precipitates such as cadmium hydroxide and cadmium carbonate. Functional groups on the microbial cell surface, such as -CH2, C=O, N-H, -COOH, phosphate groups, amino groups, and M-O moieties, participated in the bioadsorption processes of V(V) and Cd(II) heavy metals. Under optimal conditions, namely a temperature of 40 °C, pH value of 7.5, inoculation amount of 10%, salinity of 4%, COD concentration of 600 mg/L, V5+ concentration of 300 mg/L, and Cd2+ concentration of 40 mg/L, the OD 600 can reach its highest at 72 h, with the removal efficiency of V5+, Cd2+, and COD in simulated vanadium smelting wastewater reaching 86.32%, 59.13%, and 61.63%, respectively. This study provides theoretical insights and practical evidence for understanding the dynamic changes in microbial community structure under heavy metal stress, as well as the resistance mechanisms of microbial treatment of industrial heavy metal wastewater. [Display omitted] •A group of deep-sea microorganisms efficient in removing V5+ and Cd2+ was screened. •The changes in community structure of deep-sea microorganisms were analyzed. •Bio-reduction, biomineralization, and biosorption are mechanisms. •Vanadium phosphate, Cd(OH) 2 , and CdCO 3 are formed during the metal removal process. [ABSTRACT FROM AUTHOR]

The objectives of this study were to evaluate the ecophysiological state of the biota using a set of biomarkers in the upper-middle Luján River. To this aim, we collected adult Cnesterodon decemmaculatus fish, biofilm and water at three sampling sites in the upper-middle Luján River (S1: rural area, S2: Luján City and S3: urban area after passing Lujan City). For each site we determined physicochemical variables, heavy metal concentration in water, 19 biomarkers in fish (morphometric, histological, genotoxic, oxidative stress, metabolic and neurotoxic) and six biomarkers in biofilm (oxidative stress and extracellular enzyme). Additionally, we compared the responses of fish and biofilm with those of laboratory controls obtained from outdoor cultures. Our results indicated increased heavy metal concentration at all sites, mainly As and Cd, and decreased dissolved oxygen at S1 and S3. In fish, genotoxic biomarkers showed significant differences with respect to the control. The comet assay indicated damage in fish at the urbanized sites (S2 and S3) and an increased frequency of erythrocytes with nuclear aberrations at all sites. The CEA index (cellular energy allocation), calculated from the metabolic biomarkers and lipid concentration were significantly increased at S1. The gill damage evaluated histologically and with three indices indicated severe damage at all sites. Gills showed thickened primary and secondary lamellae and fusion of filaments at all sites, but a significant increase in mucous cells was only found at S1 and S3. Biofilm showed increased values of extracellular enzymes (β-glucosidase and alkaline phosphatase, lipid peroxidation and oxidative stress enzymes (i.e., catalase) at S3. These results are novel in that they incorporated laboratory controls allowing for comparisons with fish and biofilm from the field. They provided information on the status of a fish population and biofilm community, indicating the negative effect of river water deterioration on the tested organisms. Moreover, results showed what biomarkers were most sensitive for each biological sample. [Display omitted] • Lujan River showed increased concentrations of heavy metals (As, Cd). • Biomarkers in fish indicate genotoxic damage and oxidative stress in the urban area. • Histological indices indicated reduced gill surface for gas exchange at all sites. • Higher CEA and lipid content in rural area fish implied increased energy reserves. • The activity of oxidative stress enzymes in biofilm suggests environmental adaptation. [ABSTRACT FROM AUTHOR]

Microbially induced carbonate precipitation (MICP) is a promising technique for remediating heavy metal-contaminated soils. However, the effectiveness of MICP in immobilizing Cd in alkaline calcareous soils, especially when applied in agricultural soils, remains unclear. Biochar and magnesium oxide are two environmentally friendly passivating materials, and there are few reports on the combined application of MICP with passivating materials for remediating heavy metal-contaminated soils. Additionally, the number of treatments with MICP cement and the concentration of calcium chloride during the MICP process can both affect the effectiveness of heavy metal immobilization by MICP. Therefore, we conducted MICP and MICP-biochar-magnesium oxide treatments on agricultural soils collected from Baiyin, Gansu Province (pH = 8.62), and analyzed the effects of the number of treatments with cement and the concentration of calcium chloride on the immobilization of Cd by MICP and combined treatments. The results showed that early-stage MICP could immobilize exchangeable cadmium and increase the residual cadmium content, especially with high-concentration calcium chloride MICP treatment. However, in the later stage, soil nitrification and exchange processes led to the dissolution of carbonate-bound cadmium and cadmium activation. The fixing effect of MICP influence whether the MICP-MgO-biochar is superior to the MgO-biochar. Four treatments with cement were more effective than single treatment in MICP-biochar-magnesium oxide treatment, and the MICP-biochar-magnesium oxide treatment with four treatments was the most effective, with passivation rates of 40.7% and 46.6% for exchangeable cadmium and bioavailable cadmium, respectively. However, attention should be paid to the increase in soil salinity. The main mechanism of MICP-magnesium oxide-biochar treatment in immobilizing cadmium was the formation of Cd(OH) 2 , followed by the formation of cadmium carbonate. [Display omitted] • Multiple treatments with cementing solution aid in the immobilization of Cd by MICP-MgO-biochar. • MICP initially immobilizes cadmium but later activates it. • MICP and MICP-MgO-biochar mainly form Cd(OH) 2 to immobilize Cd. • The fixing effect of MICP influence whether the MICP-MgO-biochar is superior to the MgO-biochar. • The trend of changes in bioavailable Cd is similar to that of exchangeable Cd. [ABSTRACT FROM AUTHOR]

Coastal seabirds serve as sentinels of ecosystem health due to their vulnerability to contamination from human activities. However, our understanding on how contaminant burdens affect the physiological and health condition of seabirds is still scarce, raising the uncertainty on the species' vulnerability vs tolerance to environmental contamination. Here, we quantified 15 Trace Elements (TE) in the blood of gull (yellow-legged gull Larus michahellis and Audouin's gull Ichthyaetus audouinii) and shearwater (Cory's shearwater Calonectris borealis) adults, breeding in five colonies along the Portuguese coastline. Additionally, stable isotopes of carbon (δ 13C) and nitrogen (δ 15N) were quantified to elucidate foraging habitat and trophic ecology of adults, to identify potential patterns of TE contamination among colonies. We used immuno-haematological parameters as response variables to assess the influence of TE concentrations, stable isotope values, and breeding colony on adults' physiological and health condition. Remarkably, we found blood mercury (Hg) and lead (Pb) concentrations to exceed reported toxicity thresholds in 25% and 13% of individuals, respectively, raising ecotoxicological concerns for these populations. The breeding colony was the primary factor explaining variation in five out of six models, underlining the influence of inherent species needs on immuno-haematological parameters. Model selection indicated a negative relationship between erythrocyte sedimentation rate and both Hg and selenium (Se) concentrations, but a positive relationship with δ 13C. The number of immature erythrocyte counts was positively related to Hg and Se, particularly in yellow-legged gulls from one colony, highlighting the colony-site context's influence on haematological parameters. Further research is needed to determine whether essential TE concentrations, particularly copper (Cu) and Se, are falling outside the normal range for seabirds or meet species-specific requirements. Continuous monitoring of non-essential TE concentrations like aluminium (Al), Hg, and Pb, is crucial due to their potential hazardous concentrations, as observed in our study colonies. [Display omitted] • Some individuals exceeded toxicity thresholds for blood Hg and Pb concentrations. • Se:Hg molar ratios suggest that these species might be protected from Hg toxicity. • Colony emerged as a primary factor of variation in seabird health parameters. • ESR and IE counts related to δ 13C values, and Hg and Se concentrations. • Further research to assess if essential TE levels meet species-specific needs. [ABSTRACT FROM AUTHOR]

A novel adsorbent, calcium alginate-modified HAP (Hydroxyapatite)-wood ear mushroom sticks biochar (CA-HAP MB), was synthesized to enhance the immobilization of Cd and Pb in soil. Over 150 days, applying CA-HAP MB at concentrations of 0%–3% in contaminated soils from Chenzhou City in Hunan Province (CZ) and Shenyang City in Liaoning Province (SY) resulted in decreased effective concentrations of Cd and Pb. Specifically, in CZ soil, Cd and Pb decreased by 30.9%–69.3% and 31.9%–78.6%, respectively, while in SY soil, they decreased by 27.5%–53.7% and 26.4%–62.3%, respectively. Characterization results, obtained after separating CA-HAP MB from the soil, indicate that complexation, co-precipitation, and ion exchange play crucial roles in the efficient immobilization of Cd and Pb by CA-HAP MB. Additionally, adjusting the amount of CA-HAP MB added allows modulation of soil pH, leading to increased soil organic matter and nutrient content. Following treatment with CA-HAP MB for immobilizing Cd and Pb, soil bacteria abundance and diversity increased, further promoting heavy-metal immobilization. [Display omitted] • A new type of Granular adsorbent with biochar as substrate (CA-HAP MB) was designed. • CA-HAP MB enhanced immobilization of Cd and Pb in soil. • Available nutrient (N, P and K), CEC and SOM increased. • Bacterial richness and diversity in soil were restored after passivation of Cd and Pb. [ABSTRACT FROM AUTHOR]

Non-ferrous smelters emit toxic metals into the environment, posing a threat to wildlife health. Despite the acknowledged role of microbes in host health, the impact of such emissions on host-associated microbiota, especially in wild birds, remains largely unexplored. This study investigates the associations of metal pollution, fitness, and nest microbiota (serving as a proxy for early-life microbial environment) which may influence the nestling health and development. Our study focuses on three passerine birds, the great tit (Parus major), blue tit (Cyanistes caeruleus), and pied flycatcher (Ficedula hypoleuca), within control and metal-polluted sites around a Finnish copper-nickel smelter. The polluted sites had been contaminated with arsenic (As), cadmium (Cd), copper (Cu), nickel (Ni), and zinc (Zn). We performed bacterial 16S rRNA sequencing and metal analyses on 90 nests and monitored nestling body mass, fledging success, and various biotic and abiotic factors. Our findings revealed species-specific responses to metal exposure in terms of both fitness and nest microbiota. P. major and C. caeruleus showed sensitivity to pollution, with decreased nestling growth and fledging in the polluted zone. This was accompanied by a shift in the bacterial community composition, which was characterized by an increase in some pathogenic bacteria (in P. major and C. caeruleus nests) and by a decrease in plant-associated bacteria (within C. caeruleus nests). Conversely, F. hypoleuca and their nest microbiota showed limited responses to pollution, indicating greater tolerance to pollution-induced environmental changes. Although pollution did not correlate with nest alpha diversity or the most abundant bacterial taxa across all species, certain potential pathogens within the nests were enriched in polluted environments and negatively correlated with nestling fitness parameters. Our results suggest that metal pollution may alter the nest bacterial composition in some bird species, either directly or indirectly through environmental changes, promoting pathogenic bacteria and potentially impacting bird survival. [Display omitted] • Metal pollution altered the early-life microbial environment of birds. • Changes in nest microbiota composition were associated with fitness parameters. • Pathogens were increased and plant-associated bacteria decreased in polluted areas. • Species-specific responses were observed regarding both fitness and nest microbiota. [ABSTRACT FROM AUTHOR]

Fly ash from waste incineration is growing rapidly and has become a global problem. Landfill is the main treatment method, but the release behavior of ultra-alkaline fly ash needs further study. In this study, the release pattern of heavy metals from fly ash, the long-term risk after seepage, and the main control mechanisms were explored by indoor simulation experiments and process simulation modeling. The results show that carbonation is the main control mechanism for the release rate of heavy metals from super-alkaline fly ash, and the release rate is slow at the initial stage, but the release concentration of Zn and Pb may increase tens of times with the continuous reaction between the acidic substances in the leachate and the alkaline substances in the fly ash. The heavy metals released into the leachate can cause the concentration of Zn, Cd and Pb in the groundwater to exceed the standard by 39.50, 6.70 and 5.99 times due to seepage. Furnace type is the key controlling factor for background concentrations of heavy metals in ultra-alkaline fly ash, and the exposure concentrations of Cu, Cd, Zn, and Pb in ultra-alkaline fly ash from grate furnaces as well as the GT1 facility are 4.19, 4.19, 4.14, and 37.5 times greater than those of fluidized beds, respectively, with a higher risk of long-term landfill. Regionally, the regional occupancy rate of heavy metal concentrations indicated that the risk of adequate rainfall was high in the southeastern coastal region, which was five times higher than that in the inland northwest. Therefore, the long-term dynamics and risk evolution of Zn, Cd, and Pb in the groundwater around MSWLs in the coastal area should be paid attention to after the landfilling of ultra-alkaline fly ash in order to ensure the safety of the shallow groundwater environment after landfilling. Fly ash from waste incineration is growing rapidly and has become a global problem. Landfill is the main treatment method, but the release behavior of ultra-alkaline fly ash needs further study. In this study, the release pattern of heavy metals from fly ash, the long-term risk after seepage, and the main control mechanisms were explored by indoor simulation experiments and process simulation modeling. The results show that carbonation is the main control mechanism for the release rate of heavy metals from super-alkaline fly ash, and the release rate is slow at the initial stage, but the release concentration of Zn and Pb may increase tens of times with the continuous reaction between the acidic substances in the leachate and the alkaline substances in the fly ash. The heavy metals released into the leachate can cause the concentration of Zn, Cd and Pb in the groundwater to exceed the standard by 39.50, 6.70 and 5.99 times due to seepage. Furnace type is the key controlling factor for background concentrations of heavy metals in ultra-alkaline fly ash, and the exposure concentrations of Cu, Cd, Zn, and Pb in ultra-alkaline fly ash from grate furnaces as well as the GT1 facility are 4.19, 4.19, 4.14, and 37.5 times greater than those of fluidized beds, respectively, with a higher risk of long-term landfill. Regionally, the regional occupancy rate of heavy metal concentrations indicated that the risk of adequate rainfall was high in the southeastern coastal region, which was five times higher than that in the inland northwest. Therefore, the long-term dynamics and risk evolution of Zn, Cd, and Pb in the groundwater around MSWLs in the coastal area should be paid attention to after the landfilling of ultra-alkaline fly ash in order to ensure the safety of the shallow groundwater environment after landfilling. [Display omitted] • The long-term landfill risk of SAFA was assessed experimentally and by modeling. • The long-term risk of SAFA was found to be much higher than that of ordinary fly ash. • Furnace type was the main influencing factor for heavy metal concentrations in SAFA. [ABSTRACT FROM AUTHOR]

This study investigated the influence of plant-derived biochar (PB) and animal-derived biochar (AB) on behavior of heavy metals and phosphorus fractions during sewage sludge composting. PB was highly effective in reducing the bioavailability of Zn and Cu by 39% and 50%, respectively, while AB decreased the bioavailability of Pb (30%) and Cd (12%). Both biochar increased available phosphorus by over 38%. Acid extractable and bioavailable Pb in AB, and water-soluble, oxidizable and total Zn, acid extractable and oxidizable Cu in PB were positively correlated with moderately resistant organic phosphorus (MROP). Besides, in AB, Cd had strong and positive correlation with highly resistant organic phosphorus (HROP). This suggested biochar facilitated the formation of stable organometallic complexes through binding metal ions to phosphorus fractions, with notable differences based on biochar source. FT-IR showed biochar promoted humification, with PB enhancing carboxyl and polysaccharide formation, while AB encouraged quinone and aryl ether structures. These surface functional groups on the biochar likely contributed to heavy metals and phosphorus binding through chelation, adsorption, and electron shuttling. [Display omitted] • Heavy metals in PB and AB bound and precipitated with MROP through aromatic ring. • Quinone in AB led to reaction of exchangeable Cd and HROP. • PB inhibited the binding influence on LOP and heavy metals. • Zn and Cu have the hazard of reducing the formation of HCl-Pi during composting. [ABSTRACT FROM AUTHOR]

The ubiquitous presence of micro- and nanoplastics (MNPs) in soil has raised concerns regarding their potential effects on terrestrial plants. The coexistence and interactions between MNPs and heavy metals altering their phytotoxicity deserves further investigation. In this study, we explored the impacts of various concentrations of polystyrene nanoplastics (PS-NPs) and cadmium (Cd) alone or in combination on the growth and development of Arabidopsis thaliana. Additionally, we examined the effects of combined stress on the uptake and translocation of Cd within Arabidopsis thaliana. Our findings revealed several key insights: PS-NPs exhibited the capability to internalize in the maturation zone of Arabidopsis roots; the presence of Cd changed the particle size and zeta potential of PS-NPs; the presence of PS-NPs heightened Cd accumulation in the underground parts of Arabidopsis seedlings, leading to a stronger oxidative stress response in these regions; the composite stress exerted a more pronounced effect on the growth and development of Arabidopsis compared to individual stresses. Interestingly, while higher PS-NPs concentrations hindered Cd migration from roots to leaves, they also acted as carriers for Cd uptake in Arabidopsis roots. These findings shed light on the combined impacts of MNPs and heavy metals on plant physiology, offering theoretical insights to guide risk assessment strategies for MNPs and heavy metals in terrestrial ecosystems. [Display omitted] • Co-exposure to low doses of PS-NPs (0.1, 50 mg/L) and Cd reduced the phytotoxicity of Cd. • High dose of PS-NPs (100 mg/L) and Cd synergistically inhibited the growth of Arabidopsis thaliana. • PS-NPs (100 mg/L) may be internalized mainly in the maturation zone in Arabidopsis roots. • PS-NPs promoted Cd bioaccumulation in roots but inhibited Cd transport to the upper part of the plant. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are pervasive pollutants found in agricultural soils, yet research on the combined impacts of MPs and heavy metals on soil-plant systems remains limited. This study investigates the combined impact of low-density polyethylene (LDPE) microplastics (L: 1 mm, S: 100 μm, 0.1%, 1%) and Cd on soil properties, available Cd content, maize growth, and Cd accumulation by mazie through pot experiments. The findings unveiled notable impacts of the treatment groups, namely MP-L 0.1% , MP-S 0.1% , MP-L 1% , and MP-S 1% , on soil organic carbon (SOC), maize height, and catalase (CAT) activity (P < 0.05). The dosage of MPs significantly influenced maize height, MP-S 0.1% treatment resulted in a 5.6% reduction, while the other groups had insignificant effects. Particle size and dosage significantly affected SOC and CAT (P < 0.01). The MP-L 1% and MP-S 1% groups resulted in increases of SOC by 121.5% and 281.0%, respectively. CAT reductions were 32.6%, 62.8%, 41.9%, and 34.9% in MP-L 0.1% , MP-S 0.1% , MP-L 1% , and MP-S 1% groups, individually. The Cd treatment induced a significant decrease in soil cation exchange capacity (CEC), maize stem diameter, and root length, accompanied by significant increases in maize plant height, malondialdehyde (MDA), CAT, and superoxide dismutase (SOD) activities. Combined LDPE and Cd contamination had significant effects on maize height and Cd content in leaves. Specifically, MP-L 0.1% +Cd, MP-S 0.1% +Cd, MP-L 1% +Cd, and MP-S 1% +Cd reduced maize height by 4.1%, 4.5%, 8.7%, and 13.8%, respectively. The co-presence of LDPE and Cd increased available Cd content in soil while elevating Cd concentration in maize shoots and roots, with a notable 25.5% increase in Cd concentration in maize leaves in the MP-L 1% +Cd group compared to the Cd group. Furthermore, LDPE effects on soil-plant systems varied depending on particle size and dosage. This research provides important perspectives on evaluating the concurrent contamination and potential dangers of MPs and toxic metals in soil-plant environments. [Display omitted] • Low-density polyethylene (LDPE) increased the Cd content in the soil. • With LDPE alone, varied dosage and size notably reduced the maize catalase activity. • The coexistence of LDPE and Cd altered the phytoavailable of Cd in the soil. • LDPE coexisting with Cd reduced maize plant height at 1% dosing compared to 0.1%. • The dosage of LDPE significantly influenced maize height. [ABSTRACT FROM AUTHOR]

Metal(loid) bioaccumulation in acanthocephalans (Dentitruncus truttae) and intestines of fish (Salmo trutta) from the Krka River, influenced by industrial and municipal wastewaters, was investigated in relation to exposure to metal(loid)s from fish gut content (GC), water, and sediment to estimate potentially available metal (loid)s responsible for toxic effects and cellular disturbances in biota. Sampling was performed in two seasons (spring and autumn) at the reference site (river source, KRS), downstream of the wastewater outlets (Town of Knin, KRK), and in the national park (KNP). Metal(loid) concentrations were measured by ICP-MS. The highest accumulation of As, Ba, Ca, Cu, Fe, Pb, Se and Zn was observed mainly in organisms from KRK, of Cd, Cs, Rb and Tl at KRS, and of Hg, Mn, Mo, Sr and V at KNP. Acanthocephalans showed significantly higher bioaccumulation than fish intestine, especially of toxic metals (Pb, Cd and Tl). Metal(loid) bioaccumulation in organisms partially coincided to exposure from water, sediments and food, while in GC almost all elements were elevated at KNP, reflecting the metal(loid) exposure from sediments. Seasonal differences in organisms and GC indicated higher metal (loid) accumulation in spring, which follows enhanced fish feeding rates. Higher number of acanthocephalans in the intestine influenced biodilution process and lower concentrations of metal(loid)s in fish, indicating positive effects of parasites to their host, as supported by high values of bioconcentration factors. Fish intestine and acanthocephalan D. truttae were confirmed as sensitive indicators of available metal fraction in conditions of generally low environmental exposure in karst ecosystem. Since metal(loid) accumulation depended on ecological, chemical and biological conditions, but also on the dietary habits, physiology of organisms and parasite infection, continuous monitoring is recommended to distinguish between the effects of these factors and environmental exposure when assessing dietary associated metal(loid) exposure in aquatic organisms. [Display omitted] • Higher metal (loid) accumulation in acanthocephalans than fish intestine (up to 86 times). • Acanthocephalans are sensitive indicators of low and bioavailable metal levels. • Fish intestine partially reflected wastewater impact and dietborne metal (loid) uptake. • Enhanced fish feeding can contribute to higher metal (loid) accumulation. • Environmental conditions and parasite infection affect metal accumulation in fish. [ABSTRACT FROM AUTHOR]

The contamination of paddy fields by cadmium and lead is a major issue in China. The consumption of rice grown in heavy metals contaminated areas poses severe health risks to humans, where bioavailability and bioaccessibility remains the critical factor for risk determination. Selenium nanoparticles (Se-NPs) can mitigate the toxicity of heavy metals in plants. However, there exists limited information regarding the role of Se-NPs in dictating cadmium (Cd) toxicity in rice for human consumption. Moreover, the impact of Se-NPs under simultaneous field and laboratory controlled conditions is rarely documented. To address this knowledge gap, a field experiment was conducted followed by laboratory scale bioavailability assays. Foliar application of Se-NPs and selenite (at 5, 10 mg L−1) was performed to assess their efficiency in lowering Cd accumulation, promoting Se biofortification in rice grains, and evaluating Cd exposure risk from contaminated rice. Obtained results indicate that foliar treatments significantly reduced the heavy metal accumulation in rice grains. Specifically, Se-NP 10 mg L−1 demonstrated higher efficiency, reducing Cd and Pb by 56 and 32 % respectively. However, inconsistent trends for bioavailable Cd (0.03 mg kg−1) and bioaccessible (0.04 mg kg−1) were observed while simulated human rice intake. Furthermore, the foliage application of Se-NPs and selenite improved rice quality by elevating Se, Zn, Fe, and protein levels, while lowering phytic acid content in rice grains. In summary, this study suggests the promising potential of foliage spraying of Se-NPs in lowering the health risks associated with consuming Cd-contaminated rice. [Display omitted] • Foliar application of Se-NPs and selenite effectively achieved the safe rice production. • Se-NPs and selenite have shown potential in reducing the bioavailability of Cd in Caco-2 cells. • Se-NPs and selenite improved the rice quality and promoted the Se biofortification. • Se-NPs restricted the heavy metals translocation between the plant parts. [ABSTRACT FROM AUTHOR]

Bats constitute about 22% of known mammal species; they have various ecological roles and provide many ecosystem services. Bats suffer from several threats caused by anthropization, including exposure to toxic metals and metalloids. We analyzed 75 papers in a systematic literature review to investigate how species, diet, and tissue type impact bioaccumulation. Most studies documented element accumulation in fur, liver, and kidney; at least 36 metals and metalloids have been measured in bat tissues, among the most studied were mercury and zinc. Comparisons with known toxicological thresholds for other mammals showed concerning values for mercury and zinc in bat hair, lead and some essential metals in liver, and iron and calcium in kidneys. Moreover, accumulation patterns in tissues differed depending on bat diet: insectivorous bats showed higher metal concentrations in fur than in liver and kidney while frugivorous species showed higher values in liver and kidney than in fur. Finally, among the bat species that have been studied in more than two papers, the big brown bat (Eptesicus fuscus) show values of mercury in hair and copper in liver that exceed the known thresholds; as does copper in the liver of the little brown bat (Myotis lucifugus). Most studies have been conducted in temperate North America and Eurasia, areas with the lowest bat species diversity; there is a paucity of data on tropical bat species. This review points out several information gaps in the understanding of metal contamination in bats, including a lack of measured toxicity thresholds specific for bat tissues. Data on trace element bioaccumulation and its associated health effects on bats is important for conservation of bat species, many of which are threatened. [Display omitted] • Study of bat ecotoxicology is predominantly from Europe, the USA, and Australia. • Hg, Cd, Pb, and Zn exceed thresholds for mammals in certain bat tissues. • Accumulation patterns of trace elements in bats differ depending on diet. • Bat-specific toxicity thresholds are needed to assess bioaccumulation. [ABSTRACT FROM AUTHOR]

Biochar application emerges as a promising and sustainable solution for the remediation of soils contaminated with potentially toxic metal (loid)s (PTMs), yet its potential to reduce PTM accumulation in crops remains to be fully elucidated. In our study, a hierarchical meta-analysis based on 276 research articles was conducted to quantify the effects of biochar application on crop growth and PTM accumulation. Meanwhile, a machine learning approach was developed to identify the major contributing features. Our findings revealed that biochar application significantly enhanced crop growth, and reduced PTM concentrations in crop tissues, showing a decrease trend of grains (36.1%, 33.6–38.6%) > shoots (31.1%, 29.3–32.8%) > roots (27.5%, 25.7–29.2%). Furthermore, biochar modifications were found to amplify its remediation potential in PTM-contaminated soils. Biochar application was observed to provide favorable conditions for reducing PTM uptake by crops, primarily through decreasing available PTM concentrations and improving overall soil quality. Employing machine learning techniques, we identified biochar properties, such as surface area and C content as a key factor in decreasing PTM bioavailability in soil-crop systems. Furthermore, our study indicated that biochar application could reduce probabilistic health risks associated with of the presence of PTMs in crop grains, thereby contributing to human health protection. These findings highlighted the essential role of biochar in remediating PTM-contaminated lands and offered guidelines for enhancing safe crop production. [Display omitted] • Our study reveals the significant potential of biochar in promoting safe crop production. • Modifications intensify the capacity of biochar to reduce PTM accumulation in crops. • Biochar decreased soil available PTM concentration, and improved overall soil quality. • Our work identifies the contributing features for enhanced the remediation efficiency. [ABSTRACT FROM AUTHOR]

Prokaryotes are effective biosorbents for the recovery of uranium and other heavy metals. However, the potential mechanism of uranium bioaccumulation by filamentous strain (actinobacteria) remains unclear. This study demonstrates the potential for and mechanism of uranium bioaccumulation by living (L-SS) and inactivated (I-SS) Streptomyces sp. HX-1 isolated from uranium mine waste streams. Uranium accumulation experiments showed that L-SS and I-SS had efficient uranium adsorption potentials, with removal rates of 92.93 and 97.42%, respectively. Kinetic and equilibrium data indicated that the bioaccumulation process was consistent with the pseudo-second-order kinetic, Langmuir, and Sips isotherm models. FTIR indicated that the main functional groups of L-SS and I-SS binding uranium were uranyl, carboxyl, and phosphate groups. Moreover, the results of XRD, XPS, SEM-EDS, and TEM-EDS analyses revealed for the first time that L-SS has biomineralization and bioreduction capacity against uranium. L-SS mineralize U(VI) into NH 4 UO 2 PO 4 and CaU (PO 4) 2 ∙ 1.5 H 2 O through the metabolic activity of biological enzymes (phosphatases). In summary, Streptomyces sp. HX-1 is a novel and efficient uranium-fixing biosorbent for the treatment of uranium-contaminated wastewater. [Display omitted] • Actinobacteria effectively biosorb uranium and other heavy metals. • Living and inactivated Streptomyces sp. HX-1 efficiently adsorb uranium. • Living Streptomyces sp. HX-1 biomineralize and bioreduce uranium. • Streptomyces sp. HX-1 can treat uranium-contaminated wastewater. [ABSTRACT FROM AUTHOR]

The elemental accumulation has emerged as a major environmental concern due to various anthropogenic sources such as vehicles, road dust, and industrial activities, contributing to the agglutination of elements to airborne Suspended Particulate Matter (SPM). SPM-bound elements accumulate on plant surfaces impact air quality and human health due to their noxiousness. Therefore, plants' ability to capture and mitigate air pollutants plays a crucial role in urban areas. This study aimed to investigate the levels and distribution of twenty-six elements, comprised of heavy metals (Cd, Pb, Cr, Cu Zn, Co, Ni, Fe, Mn, Ag, Mo, V, Ga, and Bi), light metals (B, As, Te, and Se), and metalloids (Al, Li, Sr, K, Mg, Na, Ca, and Ba) accumulated on the surface and inside the leaves of dominant plant species during the pre-and post-monsoon at six categorized (commercial, traffic-prone, residential, educational, greenbelt and industrial areas) locations in Delhi, India. In addition, the Metal Accumulation Index (MAI) was determined, and the statistical analysis was conducted using two-way ANOVA, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA). In the pre-and post-monsoon, two-way ANOVA revealed significant differences (P < 0.05) in metal concentrations. During the pre-monsoon plants exhibited the highest metal accumulation (∼21%) at the Anand Vihar (commercial) in Delhi, with the maximum average concentrations of Cr (118.25 mg/kg), Cu (204.38 mg/kg), Zn (293.27 mg/kg), and Fe (2721.17 mg/kg). Ficus benghalensis L exhibited the maximum 213.73 MAI at the Anand Vihar in the pre-monsoon. Ni and Cr indicated the highest correlation (P < 0.05, r = 0.82) in the PCA test. HCA test revealed similarity (∼87.7%) at ITO (traffic-prone) and Okhla Phase-2 (industrial) in F. religiosa regarding metal concentration patterns. Findings highlighted seasonal elemental pollutants uptake dynamics of plant species and explored species-specific metal accumulation, revealing potential implications of metal-tolerant plants for urban greenbelt. [Display omitted] • Toxic metals in SPM from anthropogenic sources affect air quality and human health. • Plants get exposed to elevated metal content in ambient air during the pre-monsoon. • Increased Pb, Cr, and Fe levels were identified in the traffic-prone region. • F. benghalensis exhibited the maximum Metal Accumulation Index. • Plant species act as pollution sinks and bioindicators for air pollutants. [ABSTRACT FROM AUTHOR]

Mercury (Hg) is a toxic metal that presents a major risk to ecosystems, biota, human health, and remains a priority concern. In temperate and boreal lakes Hg and methylmercury (MMHg) are expected to vary as a function of atmospheric Hg deposition, lake water chemistry, catchment characteristics and climate variables. The aim of this study was to quantify Hg and MMHg in unperturbed oligotrophic lakes and to identify the factors controlling their distribution. We first hypothesized that lake Hg (and MMHg to lesser extent) spatial variations are linked to atmospheric deposition, catchment characteristics, and terrestrial exportation of dissolved organic carbon (DOC). We secondly examined if lake Hg concentrations have followed the decrease in atmospheric Hg emission observed between the mid-1990s to the end-2010s. We found that overall, atmospheric Hg has little impact on lake Hg and MMHg concentrations, which are both primarily influenced by DOC input originating from the forest catchment. The relationship between DOC and Hg differed between the spring and the fall, with a Hg-to-DOC ratio twice as high in spring. This seems related to snowmelt input of Hg (with a relatively reduced input of DOC) or the internal lake build-up of Hg during the ice-covered period. Of the 10 lakes intensively visited over a 20-year period, only 3 showed significant lake Hg decreases despite significant negative trends in atmospheric Hg concentrations, suggesting a lag between atmospheric and surface water temporal trends. Overall, terrestrial catchments retain around 80% of atmospheric Hg implying that large Hg pools have been built up in soils in the last decades. As such, the reduction of atmospheric Hg alone will not necessarily result in Hg decreases in lakes, since the Hg concentrations may be modulated by DOC export trends and catchment characteristics. This stresses the need to improve our understanding of the processes governing Hg transfers from catchments into lakes. [Display omitted] • Atmospheric Hg concentrations and deposition were measured over the last 25 years. • Lake Hg and MMHg were measured along a temporal and spatial gradient. • The negative trends in atmospheric Hg are not reflected in lake Hg concentrations. • Lake dissolved organic carbon is the best predictor of lake Hg levels. • The ratio of Hg:DOC was twice as high in spring than in fall. [ABSTRACT FROM AUTHOR]

Biochar is widely used for the remediation of heavy metal-contaminated soils. However, pristine biochar generally has limited active functional groups and adsorption sites, thereby exhibiting low immobilization performance for heavy metals. In addition to carbon (C), silicon (Si) is another common macro-element present in rice husk biochar, but it often exists in the form of amorphous oxide and therefore contributes little to the adsorption performance for heavy metals. The transformation of amorphous Si oxide to dissolved silicate through a precipitation effect can significantly improve its heavy metal immobilization capability. Herein, the amorphous Si oxide in rice husk biochar was activated by sodium hydroxide and then the dissolved silicate was immobilized by calcium salt. The as-synthetized Si-activated biochar was used to remediate cadmium (Cd)-contaminated soils. The results indicated that Si-activated rice husk biochar could reduce Cd migration and environmental risks by the transformation from exchangeable Cd into carbonate-bound and residual Cd. With increasing Ca: Si molar ratio, the content of CaCl 2 and H 2 O-extractable Cd exhibited a decreasing trend. Moreover, a higher addition amount of Si-activated biochar improved the Cd immobilization efficiency. The application of 1.0% Ca/Si molar ratio of 2: 2 Si-activated rice husk biochar decreased the CaCl 2 -Cd and H 2 O-Cd concentration by a maximum of 83.7% and 90.5% compared with pristine rice husk biochar, respectively. The present work proposes an approach for highly efficient remediation of Cd-polluted soils by biochar. [Display omitted] • Si-activated rice husk biochar was successfully synthesized by coprecipitation. • Si-activated rice husk biochar reduced H 2 O-extracted Cd concentration below 5 μg L−1 • Cd immobilization was mainly ascribed to the formation of CdSiO 3 and CdCO 3. • Si-activated rice husk biochar showed good long-term immobilization stability of Cd. [ABSTRACT FROM AUTHOR]

In solid backfill coal mining, recycled coal gangue aggregate (RCGA) is subject to the combined effects of overlying strata stress and leaching by mine water in the goaf. This process causes heavy metals to be leached and released from RCGA, which can lead to groundwater contamination. In this study, the release patterns of heavy metals in RCGA under the coupled effects of stress, solution pH, and solution flow rate were investigated, and the interactions between RCGA and the surrounding environment were explored. The findings indicate that: (1) The combined action of effective stress and mine water promotes the leaching of heavy metals. Specifically, the leaching of Pb, Zn, and Mn of RCGA is primarily influenced by the pH value of the leaching solution, while the leaching of Cu and Cr of RCGA is more closely related to the stress level; (2) Acidic environments accelerate the release of carbonate-bound fraction (CAR) in elements, facilitating the transformation of Fe/Mn oxide-bound fraction (XXI) into soluble forms; (3) The leaching ratios (Lr) of heavy metals follow the order: L rZn > L rPb > L rMn > L rCu > L rCr. This research provides guidance for the safe application of RCGA in solid backfill coal mining. [Display omitted] • Water-stress coupled leaching equipment for RCGA was developed. • Leaching behavior of heavy metals under water-stress coupling was analyzed. • Dominant factor affecting the leaching of different heavy metals was studied. • Pb and Mn are susceptible to environmental leaching. • The water-stress effect of accelerates the leaching of heavy metals from RCGA. [ABSTRACT FROM AUTHOR]

The bacteria-algae synergistic wastewater treatment process not only efficiently eliminates nutrients and absorbs heavy metals, but also utilizes photosynthesis to convert light energy into chemical energy, generating valuable bioresource. The study systematically explores the formation, algal species, and regulatory strategies of the bacterial-algal symbiosis system. It provides a detailed analysis of various interaction mechanisms, with a particular focus on nutrient exchange, signal transduction, and gene transfer. Additionally, the efficacy of the system in removing nitrogen, phosphorus, and heavy metals, as well as its role in CO 2 reduction and bioresource recycling, is thoroughly elaborated. Potential future research of bacteria-algae cell factory producing bioenergy production, feed or fertilizers are summarized. This paper clearly presents effective strategies for efficiently removing pollutants, reducing carbon emissions, and promoting resource recycling in the field of wastewater treatment. It also provides recommendations for further research on utilizing microbial-algal symbiotic systems to remove novel pollutants from wastewater and extract value-added products from the resulting biomass. [Display omitted] • Resource recovery from wastewater using bacterial-algal symbiosis is described. • Bacterial-algal interactions cover nutrient exchange, signaling, and gene transfer. • Algal-bacterial synergy can achieve a carbon reduction potential of 20%–40%. • Algal-bacterial symbiosis system can achieve 60%–95% heavy metal removal potential. [ABSTRACT FROM AUTHOR]

Culinary spices and herbs, renowned for their flavor, aroma, and medicinal properties, contain essential nutrients but also may pose health concerns due to heavy metal contamination. This systematic review, in accordance with PRISMA guidelines, investigates the global concentrations of heavy metals in culinary spices and herbs, and evaluates associated health risks. Fifty peer-reviewed studies from Scopus, PubMed, and Web of Science were examined and findings revealed variations in heavy metal content based on country of origin and spice type. In the MENA region, caraway and green cardamom from Bahrain had high levels of Pb (2.2 μg/g) and Cd (0.9 μg/g). Indian spices like cloves and Ajwain seeds exhibited high levels of iron (17.87 ± 8 mg/kg) and calcium (1353 ± 10 mg/kg). African and European spices showed regional disparities, with some exceeding permissible Pb and Cd limits. Non-carcinogenic human health risk assessments via oral exposure pathway conducted on reported Cd, Ni, and Cu concentrations throughout the reviewed global studies revealed no risks across all regions and for all spices and herbs under study except in Turkey for Cd levels found in chamomile with hazard quotients ranging between 1.26 and 1.47. On the other hand, carcinogenic risks varied based on reported Pb concentrations, ranging from 8.5 × 10−8 to a maximum of 4.96 × 10−3. These findings underscore the need for global vigilance in food safety practices and future research in countries with less stringent policies. Recommendations include improved agricultural practices, enhanced soil management, and stringent post-harvest procedures to mitigate contamination. [Display omitted] • Spices and herbs show diverse metal content, requiring safety monitoring. • Most spices and herbs are non-carcinogenic, few exhibited carcinogenic risks. • Studies recommend stringent controls to mitigate heavy metal contamination. • Review significant in future research directions and measures for spice safety. [ABSTRACT FROM AUTHOR]

Stress granules (SGs) are dynamic membraneless organelles influencing multiple cellular pathways including cell survival, proliferation, and malignancy. Hexavalent chromium [Cr(VI)] is a toxic heavy metal associated with severe environmental health risks. Low-level environmental exposure to Cr(VI) has been reported to cause cancer, but the role of SGs in Cr(VI)-induced health effects remains unclear. This study was intended to elucidate the impact of Cr(VI) exposure on SG dynamics and the role of SGs in Cr(VI)-induced malignancy. Results showed that both acute exposure to high concentration of Cr(VI) and prolonged exposure to low concentration of Cr(VI)-induced SG formation in human bronchial epithelium BEAS-2B cells. Cells pre-exposed to Cr(VI) exhibited a more robust SG response compared to cells without pre-exposure. An up-regulated SG response was associated with increased malignant properties in cells exposed to low concentration Cr(VI) for an extended period of time up to 12 months. Knocking out the SG core protein G3BP1 in Cr(VI)-transformed (CrT) cells reduced SG formation and malignant properties, including proliferation rate, sphere formation, and malignant markers. The results support a critical role for SGs in mediating Cr(VI)-induced malignancy in a G3BP1-dependent manner, representing a novel mechanism and a potential therapeutic target. [Display omitted] • Cr(VI) exposure induces SG formation. • SGs are upregulated in Cr(VI)-transformed cells. • Knocking out G3BP1 reduces the malignant properties of Cr(VI)-transformed cells. • This is a novel mechanism that SGs play critical role in Cr(VI) induced malignancy. [ABSTRACT FROM AUTHOR]

In order to understand the transfer of macroelements and toxic metals in the terrestrial food web, barn swallows, terrestrial frogs, and insects were collected from farmlands in the Leizhou Peninsula, and analyzed for macroelements carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) and trace metals nickel (Ni), zinc (Zn), selenium (Se), copper (Cu), chromium (Cr), cadmium (Cd), lead (Pb), and mercury (Hg). The multi-element ecological stoichiometry was discussed to trace the food web flow of nutrients and toxicants. The percentage contents of C, N, P, and S were 35.43–59.91%, 6.89–12.11%, 0.49–4.66%, and 0.44–2.19%, respectively. The concentrations of Ni, Zn, Se, Cu, Cr, Cd, Pb, and Hg were 0.163–116 mg/kg, 38.7–227 mg/kg, 0.0453–3.82 mg/kg, 3.11–141 mg/kg, not detected—79.6 mg/kg, 0.0203–0.358 mg/kg, 0.148–4.57 mg/kg, and 0.00159–1.46 mg/kg, respectively. Organisms at high trophic levels had higher contents of N, P, and S, and lower contents of C. Significant correlations were observed between δ15N and ratios of C: N, C: P, C: S, N: P, N: S, and S: P, indicating selective transfer of biogenic elements for predators in the terrestrial food web. Most metals including Ni, Zn, Se, Cu, Cr, Pb, and Hg had biomagnification factors and trophic magnification factors higher than 1, because the whole body of organisms rather than tissues were used. The negative correlations between the detoxification ratios of Se: X (each toxic metal) and metal concentrations suggest potential adverse effect of metals on terrestrial organisms. [Display omitted] • Terrestrial predators at higher trophic levels have higher demand for N, P, and S. • All eight heavy metals except Cd biomagnified in this terrestrial food web. • The risk of metals may be underestimated by using individual tissues for predators. • Se showed potential detoxification of most metals in this terrestrial food web. [ABSTRACT FROM AUTHOR]

The exposure of the African catfish (Clarias gariepinus) to various environmental contaminants leads to physiological and histological alterations. Therefore, the study aimed to assess the impact of seasonal variations of ecological contaminants as external stressors and internal stressors via helminth infections on oxidative stress and histopathology in resident C. gariepinus at EL-Salam Canal, Egypt. Seasonal water and sediment samples were collected to assess physicochemical parameters and heavy metals. The length, weight, and sex were recorded for each fish sample. The gastrointestinal tract was dissected from the visceral cavity, and the helminths were extracted and identified using SEM photos based on their morphological characteristics. The parasitic dominance in the gastrointestinal helminths was calculated. The heavy metal concentrations, bioaccumulation (BAF), and biosedimentation (BSF) factors were considered in the muscles and intestine. Specimens of muscles and intestines were removed to determine oxidative status. In addition, pieces of skin, muscles, stomachs, and intestines were subjected to light microscopy to determine the alterations. The calcium, magnesium, and potassium levels were within safe limits. Sulfate levels consistently remained below the maximum permissible thresholds throughout the seasons. Among the heavy metals examined, the highest accumulation was found in the intestinal tissues of C. gariepinus , while muscle tissues showed lower levels. The variability in metal concentrations across water, sediment, muscles, and intestines underscores the different capacities of these environments to accumulate heavy metals. The elevated metal levels in fish tissues raise concerns about potential health risks for humans who consume contaminated fish, highlighting significant bioaccumulation within the food chain. The result indicated that Cu in the sediment samples was associated with parasite abundance. The dual stress from environmental pollutants and parasitic infections exacerbates oxidative stress and causes notable histopathological changes in the tissues of the catfish. These results highlight the intricate interplay between external and internal stressors, emphasizing the need for continuous monitoring and management of aquatic ecosystems to safeguard the health of resident fish populations. It provides insight into how these factors affect fish health. [Display omitted] • Impact of ecological contaminants and parasitic infections on fish health. • Emphasizing the importance of addressing both external and internal stress factors in aquatic environments. • The necessity for continuous monitoring and management of aquatic ecosystems. [ABSTRACT FROM AUTHOR]

The migration of heavy metals into aquatic ecosystems is a concern for the safety of aquatic organisms and human health. However, the migration of heavy metals from habitats to the food chain in freshwater ecosystems requires extensive exploration. We extensively investigated the levels of heavy metals in multiple media of freshwater ecosystems and explored their migration from freshwater habitats to the food chain. The results showed that the concentrations of Cr, Cu, Cd, Zn, Sb, and Pb in sediments, Cr in mollusks, and Cd in clams exceeded their standard limit values. Feeding habits, species, and body length considerably affected heavy metal levels in fish, whereas regional differences, body length, and weight considerably affected heavy metal levels in mollusks. The bioconcentration capacity (improved biotawater (sediment) accumulation factors) of the muscles was higher than that of the gills and visceral mass. Mollusks were strongly enriched in Cu, Cd, Zn, and Mn in their habitats, whereas fish were more favourable for the accumulation of Cu, Zn, and Cr. Heavy metals in sediments pose a higher risk to aquatic organisms than those in the overlying water. Trophic level (TL) (δ15N) considerably diluted levels of most metals, whereas Cu and Zn levels increased along the organic matter pathway (δ13C) in the entire aquatic food chain. The levels of typical pollutants, such as Cu, Zn, As, Cd, Pb, and Cr changed considerably along the organic matter pathway in mollusks. The levels of heavy metals in fish were not affected by TL or organic matter pathway, except for Cu. The potential risk of consuming aquatic organisms from Poyang Lake was ranked as clams > snails > fish for adults and children and As in aquatic organisms was the primary contributor to health risk. [Display omitted] • Muscles had higher bioaccumulation capacities of heavy metal referenced iron. • Trophic levels as a whole had a significant dilution on heavy metals. • Cu level was significantly magnified along the organic matter pathway. • Levels of Cu, Zn, As, Cd, Pb, and Cr in mollusks were sensitive to Organic matter pathway. • Metal levels in fish insensitive to organic matter pathway and trophic level. [ABSTRACT FROM AUTHOR]

Bioremediation, an economical and environmentally friendly approach, provides a sustainable solution for mitigating heavy metal contamination in soils. This study identifies four fungal strains— Trichoderma harzianum DAA8, Trichoderma reesei DAA9, Rhizomucor variabili s DFB3, and Trichoderma asperellum LDA4—that exhibit tolerance to cadmium (Cd) and chromium (Cr). These strains were isolated from soils impacted by heavy metal contamination in mining regions. Rigorous examinations of these strains led us to determine their Minimum Inhibitory Concentrations (MICs) and optimal absorption-reduction conditions. Our microscopic data and GC-MS analysis indicate that these strains can accumulate Cd and Cr by generating compounds, such as ketones and imines, in heavy metal environments. We evaluated the remediation efficacy of both single and co-cultures of Rhizomucor variabilis DFB3 and Trichoderma asperellum LDA4 in conjunction with king grass, a plant known for its heavy metal accumulation capabilities. Our findings indicated an impressive 41.9% increase in plant biomass and 47.2% and 64.4% increase in Cd and Cr accumulation respectively. The removal rates of Cd and Cr were 16.5% and 19.0%, respectively, following the co-inoculation of Rhizomucor variabilis DFB3 and Trichoderma asperellum LDA4. These rates represent increases of 37.1% and 33.7% compared to the removal rates achieved with king grass alone. This study not only advances strategies to manage Cd-Cr contamination but also sets a pathway for efficient heavy metal soil remediation using a microbial-plant combined technique. [Display omitted] • Four Cd/Cr-tolerant fungal strains were isolated. • Strains synthesize ketones and imines, enhancing Cd/Cr accumulation. • Superior biosorption of Cd/Cr with specific three-strain consortia. • R. variabilis and T. asperellum enhance king grass yield and bioremediation. [ABSTRACT FROM AUTHOR]

Heavy metals increase in nature due to anthropogenic activities and negatively impact the growth, progress, and efficiency of plants. Among the toxic metal pollutants that can cause dangerous effects when accumulated by plants, mercury (Hg) and cadmium (Cd) were investigated in this study. These metals typically inhibit important enzymes and halt their functioning, thereby adversely affecting the capability of plants to achieve photosynthesis, respiration, and produce quality crops. Acetylcholine (ACh) serves as a potent neurotransmitter present in both primitive and advanced plant species. Its significant involvement in diverse metabolic processes, particularly in regulating growth and adaptation to stress, needs to be further elucidated. For this aim, effects of acetylcholine (ACh1, 10 μM; ACh2, 100 μM) were survey in Triticum aestivum under Hg and/or Cd stress (Hg, 50 μM; Cd, 100 μM). Wheat seedlings exhibited a growth retardation of about 24% under Hg or Cd stress. Combined stress conditions (Cd + Hg) resulted in a decrease in RWC by approximately 16%. Two different doses of ACh treatment to stressed plants positively affected growth parameters and regulated the water relations. Gas exchange was limited in stress groups, and the photochemical quantum competency of PSII (F v /F m) was suppressed. Cd + ACh1 and Cd + ACh2 treatments resulted in approximately 2-fold and 1.5-fold improvement in stomatal conductance and carbon assimilation rate, respectively. Similarly, improvement was observed with ACh treatments in wheat seedlings under Hg stress. Under Cd and/or Hg stress, high levels of H 2 O 2 accumulated and lipid peroxidation occurred. According to our results, ACh treatment upon Cd and Hg stresses improved the activities of SOD, POX, and APX, thereby reducing oxidative damage. In conclusion, ACh treatment was found to ensure stress tolerance and limit the adverse effects caused by heavy metals. [Display omitted] • Heavy metal stress caused growth retardation in wheat seedlings. • Cd and Hg suppressed the photosynthetic capacity of wheat leaves. • ACh reduced oxidative stress in wheat leaves under heavy metal pollution. • ACh alleviated the negative effects of stress on physiological parameters. • ACh treatment improved antioxidant activity and provided resilience. [ABSTRACT FROM AUTHOR]

Trace elements in game meats remain a point of concern for both the public and policymakers alike due to the human health implications if levels present are above guideline limits. This study aimed to: (1) determine trace element concentrations (As, Cd, Hg, Pb Cr, Cu, Se, Zn) in edible portions (breast meat and liver) of the four most frequently hunted duck Anatidae species inhabiting wetlands in Victoria, Australia, to identify the risk to human health from consumption; (2) investigate landscape-scale variables that may influence the detected concentrations and; (3) review the studies available (n = 41) in duck liver and muscle tissues from the 1970s to 2024, to contextualise the detected concentrations found on a global scale. Our study shows that ducks in Victoria had trace element concentrations below tolerable daily intake (TDI) guidelines for human health with one exception: notably high Hg in a filter-feeding specialist, the Pink-eared duck (Malacorhynchus membranaceus). Yet, the only trace element concentrations that were influenced by proximity to populated centres, were As and Zn. Compared to international reports, Pb concentrations in livers and muscle of Victorian waterfowl were lower, however, Pink-eared ducks had higher Hg than other duck (Anas spp.) species. Review of the worldwide data indicate that Pb concentrations in liver tissues from all Anas species have declined from the 1970s to 2024. This is the first study to identify this trend at a global scale. International movements towards Pb-shot bans, along with phasing out of Pb in gasoline and paint are the most likely cause of declining concentrations in tissues of wild waterfowl. These findings strongly underscore the importance of legislative efforts to limit trace elements entering the environment. [Display omitted] • Trace elements in Victorian game ducks are low compared to global Anas species. • Most ducks had trace element levels below TDI guidelines for human health. • A global review in Anas ducks suggest declining Pb levels in liver since the 1970s. • High Hg concentrations in filter-feeding ducks may have human health implications. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a dangerous environmental contaminant. Jute (Corchorus sp.) is an important natural fiber crop with strong absorption and excellent adaptability to metal-stressed environments, used in the phytoextraction of heavy metals. Understanding the genetic and molecular mechanisms underlying Cd tolerance and accumulation in plants is essential for efficient phytoremediation strategies and breeding novel Cd-tolerant cultivars. Here, machine learning (ML) and hyperspectral imaging (HSI) combining genome-wide association studies (GWAS) and RNA-seq reveal the genetic basis of Cd resistance and absorption in jute. ML needs a small number of plant phenotypes for training and can complete the plant phenotyping of large-scale populations with efficiency and accuracy greater than 90%. In particular, a candidate gene for Cd resistance (COS02g_02406) and a candidate gene (COS06g_03984) associated with Cd absorption are identified in isoflavonoid biosynthesis and ethylene response signaling pathways. COS02g_02406 may enable plants to cope with metal stress by regulating isoflavonoid biosynthesis involved in antioxidant defense and metal chelation. COS06g_03984 promotes the binding of Cd2+ to ETR/ERS, resulting in Cd absorption and tolerance. The results confirm the feasibility of high-throughput phenotyping for studying plant Cd tolerance by combining HSI and ML approaches, facilitating future molecular breeding. [Display omitted] • This investigation combines the HSI and ML methods for the first time. • The accuracy of phenotypic analysis using ML method was more than 90%. • We identified two candidate genes for Cd-resistance and tolerance in jute. [ABSTRACT FROM AUTHOR]

This study investigated the efficacy of incorporating nitric oxide (NO; 10 μM) and ascorbic acid (Asc; 10 μM) into the culture medium to confer cadmium (Cd; 5 μM) tolerance in thyme (Zataria multiflora). The phytotoxicity of Cd resulted in a decrease in shoot biomass, which NO or Asc mitigated. Adding Asc and NO to the culture medium was associated with substantial DNA hypomethylation. The NO + Cd and Asc + Cd treatments were accompanied by an increase in the unmethylation percentages, about 3-fold higher than the control. The hemi-methylation percentages in the Asc-supplemented seedlings also displayed an upward trend. The transcriptional upregulation in the γ-terpinene synthase (TPS) gene resulted from the applied elicitors, especially NO. In response to the NO and Asc treatments, the transcription of two cytochrome P450 monooxygenase genes (CYP71D178 and CYP71D180) went up. Incorporating Asc or NO into the culture medium enhanced the concentrations of proline, carvacrol, and thymol metabolites. Employing NO or Asc mitigated the 43% decrease in protein content due to the Cd cytotoxicity. The NO and Asc applications improved the activity of the phenylalanine ammonia-lyase (PAL) enzyme. NO and Asc utilization increased the accumulation of flavonoids. NO and Asc also up-regulated the activities of two enzymatic antioxidants (catalase and peroxidase). Collectively, this study provided novel insight into how Asc or NO confers Cd tolerance by epigenetically remodeling DNA methylation, transcriptionally up-regulating terpenoid and phenylpropanoid metabolism, increasing proline concentration, and improving antioxidants. [Display omitted] • Epigenetic DNA hypomethylation contributes to mitigating Cd cytotoxicity. • Nitric oxide (NO) and ascorbate (Asc) transcriptionally improved terpenoid metabolism. • NO and Asc transcriptionally upregulated CYP71D178 and CYP71D180 genes. • NO and Asc conferred Cd tolerance by stimulating terpenoid and phenylpropanoid metabolism. • NO and Asc alleviated Cd risks by increasing proline osmo-protectant and reinforcing antioxidants. [ABSTRACT FROM AUTHOR]

Municipal solid waste incineration fly ash (IFA) designated as hazardous waste poses risks to environment and human health. This study introduces a novel approach for the stabilization and solidification (S/S) of IFA: a combined approach involving alkali treatment and immobilization in low-carbon supersulfated cement (SSC). The impact of varying temperatures of alkali solution on the chemical and mineralogical compositions, as well as the pozzolanic reactivity of IFA, and the removal efficiency of heavy metals and metallic aluminum (Al) were examined. The physical characteristics, hydration kinetics and effectiveness of SSC in immobilizing IFA were also analyzed. Results showed that alkali treatment at 25 °C effectively eliminated heavy metals like manganese (Mn), barium (Ba), nickel (Ni), and chromium (Cr) to safe levels and totally removed the metallic Al, while enhancing the pozzolanic reactivity of IFA. By incorporating the alkali-treated IFA and filtrate, the density, compressive strength and hydration reaction of SSC were improved, resulting in higher hydration degree, finer pore structure, and denser microstructure compared to untreated IFA. The rich presence of calcium-aluminosilicate-hydrate (C-(A)-S-H) and ettringite (AFt) in SSC facilitated the efficient stabilization and solidification of heavy metals, leading to a significant decrease in their leaching potential. The use of SSC for treating Ca(OH) 2 - and 25°C-treated IFA could achieve high strength and high-efficient immobilization. [Display omitted] • Alkali treatment removed metallic aluminium and some heavy metals in fly ash (IFA). • Alkali-treated IFA improved hydration and compressive strength of SSC. • SSC effectively immobilized IFA due to hydration products solidified heavy metals. • Synergy of alkali treatment and SSC is a promising method for immobilizing IFA. [ABSTRACT FROM AUTHOR]

The global increase in electronic waste (e-waste) has led to a rise in informal recycling, emitting hazardous heavy metals (HMs) that threaten human health and ecosystems. This study presents the first comprehensive assessment of HM levels in dry deposition and soils at proximity of forty (40) informal e-waste recycling sites across Pakistan, between September 2020 to December 2021. Findings reveal that Zn (1410), Pb (410) and Mn (231) exhibited the higher mean deposition fluxes (μg/m2.day), derived from air samples, particularly in Karachi. Similarly, soils showed higher mean concentrations (μg/g dw) of Mn (477), Cu (514) and Pb (172) in Faisalabad, Lahore, and Karachi, respectively. HMs concentrations were found higher in winter or autumn and lower in summer. In addition, HM levels were significantly (p = 0.05) higher at recycling sites compared to background sites year-round, highlighting the e-waste recycling operations as the major source of their emissions. The I geo index indicated moderate to extremely contaminated levels of Cu, Pb, Cd, and Ni in Karachi, Lahore and Gujranwala. Ingestion was found as a leading human exposure route, followed by dermal and inhalation exposure, with Pb posing the greatest health risk. The Cumulative Incremental Lifetime Cancer Risk (ILCR) model suggested moderate to low cancer risks for workers. Strategic interventions recommend mitigating health and environmental risks, prioritizing human health and ecosystem integrity in Pakistan's e-waste management. [Display omitted] • Informal e-waste recycling in Pakistan emits Zn, Mn, Pb, harming health/ecosystems. • Heavy metal concentration in air and soil for Karachi were the highest and warrant further attention. • Heavy metals in air exhibited seasonality and peaked in autumn/winter. • High human exposure estimates for Pb highlight the need for improved e-waste management in Pakistan. [ABSTRACT FROM AUTHOR]

Atmospheric pollution is a major public health issue and has become increasingly critical for human health. Urban atmospheric pollution is typically assessed through physicochemical indicators aligned with environmental legislation parameters, providing data on air quality levels. While the effects of pollution on sensitive organisms serve as a warning for public health decision-makers, there remains a need to explore the interpretation of environmental data on pollutants. The use of species adapted to urban environments as sentinels enables continuous and integrated monitoring of environmental pollution implications on biological systems. In this study, we investigated the use of the plant species Tradescantia pallida as a biomonitor to evaluate the genotoxic effects of atmospheric pollution under diverse vehicular traffic conditions. T. pallida was strategically planted at the leading urban intersections in Uberlândia, Brazil. During COVID-19 pandemic lockdowns, we compared indicators such as physical, biological, and traffic data at different intersections in residential and commercial zones. The reduction in vehicular traffic highlighted the sensitivity of plant species to changes in air and soil pollutants. T. pallida showed bioaccumulation of heavy metals Cd and Cr in monitored areas with higher traffic levels. Additionally, we established a multiple linear regression model to estimate genotoxicity using the micronucleus test, with chromium concentration in the soil (X1) and particulate matter (PM) in the atmosphere (X2) identified as the primary independent variables. Our findings provide a comprehensive portrait of the impact of vehicular traffic changes on PM and offer valuable insights for refining parameters and models of Environmental Health Surveillance. [Display omitted] • Concentrations of Cd and Cr were higher in soil from sites of commercial activity. • T. pallida was sensitive to environmental changes in air and soil pollutants. • T. pallida bioaccumulated heavy metals, indicating vehicular traffic influence. • Genotoxicity was correlated with Cr in soil and PM in the atmosphere. • PM 2.5 was the primary variable responsible for the increase in micronuclei frequency. [ABSTRACT FROM AUTHOR]

Lead (Pb) and cadmium (Cd) have been identified as the primary contaminants in soil, posing potential health threats. This study aimed to examine the effects of applying a nitrogen fertilizer and a fungal agent Trichoderma harzianum J2 (nitrogen alone, fungi alone, and combined use) on the phytoremediation of soils co-contaminated with Pb and Cd. The growth of Leucaena leucocephala was monitored in the seedling, differentiation, and maturity stages to fully comprehend the remediation mechanisms. In the maturity stage, the biomass of L. leucocephala significantly increased by 18% and 29% under nitrogen-alone (NCK+) and fungal agent-alone treatments (J2), respectively, compared with the control in contaminated soil (CK+). The remediation factors of Pb and Cd with NCK+ treatment significantly increased by 50% and 125%, respectively, while those with J2 treatment increased by 73% and 145%, respectively. The partial least squares path model suggested that the nitrogen-related soil properties were prominent factors affecting phytoextraction compared with biotic factors (microbial diversity and plant growth). This model explained 2.56 of the variation in Cd concentration under J2 treatment, and 2.97 and 2.82 of the variation in Pb concentration under NCK+ and J2 treatments, respectively. The redundancy analysis showed that the samples under NCK+ and J2 treatments were clustered similarly in all growth stages. Also, Chytridiomycota , Mucoromucota , and Ciliophora were the key bioindicators for coping with heavy metals. Overall, a similar remediation mechanism allowed T. harzianum J2 to replace the nitrogen fertilizer to avoid secondary pollution. In addition, their combined use further increased the remediation efficiency. [Display omitted] • Trichoderma harzianum J2 exhibited plant-promoted and Pb–Cd-enriched traits. • Inoculation increased BF, TF, and RF in Leucaena leucocephala , particularly for Pb. • Inoculation regulated nitrogen cycling and improved microbial community structure. • Soil nitrogen properties were key drivers for the removal of Pb and Cd. • Bio-fertilizer J2 could replace nitrogen fertilizers for Pb–Cd remediation. [ABSTRACT FROM AUTHOR]

Numerous edible mushrooms accumulate Potentially Toxic Elements (PTE), such as cadmium, mercury, and lead, within their sporocarps. This accumulation poses a potential risk of poisoning for humans and is influenced by factors such as the mushroom species, type of element, and the level of industrialization in the region. In our study, we investigated how soil and tree stand characteristics, including C/N ratio, pH, tree diversity, canopy cover, and the proportion of deciduous trees, influence PTE concentration in mushrooms. We collected edible mushrooms from 20 plots situated in the Białowieża Primeval Forest, one of Europe's best-preserved lowland forests. Plots varied in terms of tree species composition, with other factors minimized. We used ICP-MS (Inductively Coupled Plasma - Mass Spectrometry) technique to analyze the concentration of eight PTE (Ag, As, Cd, Ni, Pb, Sb, Sr, Tl) in eight edible mushroom species (M.procera , L.perlatum , R. butyracea , R.cyanoxantha , R.heterophylla , L.vellereus , A.mellea, and Xerocomellus chrysenteron). Our research revealed that the presence of the effect of specific factors on concentration of PTE and its direction depends on mushroom species and type of PTE. The proportion of deciduous tree species and pH of the topsoil layer emerged as the most influential factors affecting PTE concentration in mushroom samples. Tree species richness in the canopy layer did not affect PTE concentration in mushrooms, except for the concentration of Pb in X. chrysenteron. We observed a consistent profile of PTE concentration in mushrooms with similar ecological roles (ectomycorrhizal, saprotrophic, parasite mushrooms) and from comparable phylogenetic affinities. [Display omitted] • Impact of soil and tree stand properties on PTE content in mushrooms was analyzed • Deciduous tree proportion and pH of topsoil affected PTE content the most • The effect of environmental factors is modulated by mushroom species and metal type • M.procera and X.chrysenteron were affected by environmental factors the most • Similar ecological roles and phylogenetic affinities favour similar PTM profiles [ABSTRACT FROM AUTHOR]