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At least 19 recordsLinked to original sources
PubMed2026

From ecological threats to environmental solutions: a critical review of invasive plant species for heavy metal phytoremediation.

Heavy metal contamination represents a persistent environmental challenge threatening ecosystem stability, agricultural productivity, and human health. Therefore, the development of sustainable and cost-effective remediation strategies is essential. Phytoremediation, an environmentally compatible approach that utilizes plants and their associated biological processes to reduce contaminant mobility, bioavailability, and toxicity, has gained increasing attention as an alternative to conventional remediation techniques. Among potential phytoremediation candidates, invasive plant species (IPS) have attracted interest due to their rapid growth, high biomass production, extensive root systems, physiological plasticity, and tolerance to stressful environments, including heavy metal contamination. Species such as Alternanthera philoxeroides, Arundo donax, Eichhornia crassipes, and Pistia stratiotes have demonstrated potential for metal uptake, accumulation, immobilization, or tolerance in contaminated ecosystems. This review critically examines the role of invasive plants in heavy metal phytoremediation by evaluating the physiological, biochemical, and ecological traits that influence remediation outcomes. Key mechanisms, including phytoextraction, phytostabilization, rhizosphere-mediated processes, and plant-microbe interactions, are discussed using evidence from contaminated soil and aquatic environments. The potential advantages of invasive plants, particularly their high biomass production and environmental adaptability, are evaluated alongside ecological concerns associated with their utilization. Importantly, invasion success does not necessarily translate into remediation success, and the effectiveness of invasive plants depends on contaminant characteristics, ecosystem conditions, and management practices. Major challenges, including uncontrolled spread, ecosystem disruption, contaminated biomass management, and limited field-scale validation, are critically assessed. Overall, invasive plants represent context-dependent remediation resources rather than universal solutions. Their application requires integrated risk assessment, containment strategies, long-term monitoring, and evidence-based management frameworks to maximize remediation benefits while minimizing ecological risks.

Contamination↗
PubMed2026

Fungi to the rescue: recent advances, mechanistic insights and omics-based perspectives in heavy metal mycoremediation.

Heavy metal (HM) contamination arising from rapid industrialization poses critical threats to global ecosystem integrity and public health. Conventional physicochemical approaches are limited by high costs, incomplete removal, and toxic waste generation, necessitating sustainable alternatives. Mycoremediation, which harnesses the remarkable, diverse capacities of fungi to tolerate and mitigate HM stress through sophisticated biological mechanisms, has emerged as a promising and sustainable approach to address HM pollution. This review examines the sources and ecotoxicological impacts of HM pollution, alongside the intracellular and extracellular mechanisms underlying fungal tolerance and removal, including biosorption, precipitation, membrane transport, antioxidant defense, chelation, bioaccumulation, and biotransformation. It further synthesizes fungal-based bioremediation strategies, while examining how metagenomic, metatranscriptomic, transcriptomic, proteomic, and metabolomic approaches are advancing understanding of fungal community structure and active detoxification pathways. This work uniquely integrates community- and isolate-level multi-omics data, explicitly bridges mechanistic understanding with omics-driven insights, and extends this into translational roadmap for applied bioremediation.

Biodegradation, Environmental↗
PubMed1978

Heavy metal nephropathy of rodents.

Heavy metal nephropathy is a pathologic entity of the renal tubular epithelium of rats, evoked by lead, gold, and other heavy metals. It is characterized acutely by coagulative necrosis, subacutely by cortical fibrosis, and chronically by cytomegaly and karyomegaly. Finally, adenomas develop, some of which become malignant.

Adenoma↗
PubMed1977

Nutritional factors in relation to heavy metal toxicants.

An increased environmental exposure to various toxic heavy metals such as lead, cadmium, or mercury seems to be a fact of 20th-century life. But relatively little attention has been paid to the possible implications of sucy exposure for the nutritional status of humans and animals. This review summarizes the information available concerning the effect of various nutritional factors in resistance to metal toxicants and the effect of heavy metal toxicity on nutritional status. In particular, the following questions are considered: 1) Are there any examples of heavy metal toxicity that are potentiated by a nutritional deficiency? 2) Is there any evidence that nutritional deficiency can be caused by heavy metal toxicity? 3) Is there any proof that heavy metal toxicity can be decreased by an excess intake of nutrients: 4) Is there any proof that heavy metal toxicity can be increased by an excess intake of nutrients? The discussion is focused primarily on studies with animal models but, wherever possible, implications for human health are pointed out.

Animals↗
PubMed2026

Antarctic Peninsula soil carbon stock and efflux: A complex interplay of soil properties and heavy metals.

This study establishes a quantitative framework for understanding surface soil carbon dynamics and ecosystem connectivity in Fildes Peninsula and Ardley Island, King George Island, South Shetland Islands, Antarctic Peninsula. The mean soil organic carbon (SOC) stock across all study sites was 1.10 ± 1.93 kg C/m². Restricting net carbon balance analysis to Fildes Peninsula, where soil respiration (Rs) data were available, yielded a site-specific SOC stock of 0.45 ± 0.45 kg C/m². Scaling Rs to a realistic 120-day active season and assuming stable SOC stocks resulted in estimated annual carbon loss of 15 g C/(m2·yr), equivalent to 3.3 % of standing SOC. Comprehensive sensitivity analyses spanning plausible winter respiration (0 %-20 % of summer rates) and annual change in SOC stocks (-1 %-2 %) consistently supported a net carbon sink, with turnover rates constrained to 3.3 %/yr-4.7 %/yr. Principal component analysis showed that ornithogenic processes as the dominant control on SOC, total nitrogen (TN), zinc (Zn), copper (Cu), and cadmium (Cd) provide a clear multivariate signature of marine-derived nutrient, while Pb was decoupled from this gradient and associated instead with fine-particle size controls. These results reveal dual but independent drivers of soil metal enrichment in this region. Despite their limited spatial extent, ornithogenic soils store disproportionately large carbon pools. Overall, this integrated analysis reveals how marine-terrestrial subsidies regulate Antarctic carbon cycling and provides a quantitative and reproducible framework for assessing carbon dynamics under ongoing climate change.

Antarctic Regions↗
PubMed2026

Leveraging environmental applications and risks of coal gangue: A critical review on authigenic inorganic heavy metals, organic contaminants, and the removal of exogenetic contaminants.

Coal gangue (CG) as bulk solid waste has seriously threatened the ecosystem. Therefore, identifying the key risk drivers and exploring feasible disposal methods for CG are essential for developing a sustainable strategy. However, there is currently a lack of comprehensive information that balances the contamination risks with the valuable constituents present in CG, which hinders its full potential for sustainable use without negative environmental impacts. Given the complex composition and associated risks, we propose that addressing the critical properties related to contamination is crucial for the efficient utilization of CG. On this premise, we summarized several practical resource pathways (ecological multifunctional materials, extraction of rare elements, and soil additives) that are more favorable for sustainable development relative to conventional disposals. Meanwhile, we also propose that coupling disposals could intensely reduce CG's environmental footprints and capital costs. Consequently, regardless of the number of challenges to be solved, we believe the CG has broad application prospects, and we hope this review will promote the conversion of CG into an asset with lower ecological and social impacts.

Metals, Heavy↗
PubMed1979

Studies on urea hydrolysis. Part 2. Effects of some heavy metals on urease activity.

The effect of some heavy metals on the urease activity was studied in a pure system using jack bean urease (JBU). While Mn showed no effect, copper reduced the enzyme activity more than did Zn or Fe at high concentrations (100 ppm). At a low concentration, iron reduced the enzyme activity more than at a high concentration. Inhibition of the urease activity was induced by less than 0.1 ppm Fe, 0.5 ppm Cu, and 10.0 ppm Zn. In the soil, these heavy metals inhibited the JBU in this order: Fe++ greater than Cu++ greater than Zn++. The possibility is discussed of using heavy metals to delay urea hydrolysis in soils.

Copper↗
PubMed1977

Sulfide silver architectonics of rat, cat, and guinea pig spinal cord. A light microscopic study with Timm's method for demonstration of heavy metals.

The distribution of heavy metals in the spinal cord of the cat, rat, and guinea pig has been studied histochemically with Timm's sulfide silver method. There was considerable variation in the degree of staining of the neuropil. The dorsal horn showed a laminar staining pattern corresponding to the cytoarchitectonic lamination. Lamina I in the cat and guinea pig was light. Lamina II in all three species was heavily stained. In the rat and guinea pig it could be subdivided in a ventral and a dorsal layer, and moreover in the rat a darkly staining borderzone abutting on lamina III was present. Lamina III, characterized by heterogeneous staining, also appeared dark, although less obvious in the guinea pig. In the ventral horn the coarser stained particles in lamina IX contrasted with the surrounding lamina. Cell staining varied between different cell groups, and within single cell populations. In the cat thoracic cord the cells in nucleus intermedio-lateralis (IL) and nucleus intercalatus (IC) stained very weakly. In Clarke's column and in the motoneuron area cells, uniform in Nissl preparations, could be seen different after Timm staining. The results are discussed in relation to other histochemical patterns, cytoarchitectonics, and terminal fields of afferents. Considerable correlation of the Timm pattern to these data was found.

Animals↗
PubMed1979

Influence of the acute intoxication with salts of some heavy metals on hexobarbital sleep and hexobarbital metabolism.

The effect of acute intoxication with salts of ten heavy metals on hexobarbital sleep and the dependence of this effect on the time of application and the dose of the heavy metal are studied in experiments on male albino rats. Two hours after subcutaneous injection of toxic doses, only cobalt nitrate significantly prolongs hexobarbital sleep. Significant prolongation of the sleep is observed at the 24th hour in intoxication with CuSO4, CdSO4, Co(NO3)2, Pb(CH3COO)2, ZnSO4, NiSO4, while As2O3, HgCl2, Bi(NO3)2 and SnCl2 do not change it. All heavy metals (with the exception of NiSO4) prolong significantly hexobarbital sleep 96 hours after the intoxication. At the 24th hour after intoxication with salts of heavy metals, the hexobarbital level in the blood serum at the 30th min after its administration is significantly higher for Co(NO3)2, CdSO4, NiSO4, and it tends to be higher for CuSO4 and Pb(CH3COO)2. This, together with the significant inhibition of the hexobarbital-oxidizing enzyme system in the case of Cu, Co, Cd and Pb, suggests that in the case of these heavy metals potentiation of the hexobarbital sleep is largely due to inhibition of the hexobarbital metabolism. No significant prolongation of hexobarbital sleep or changes in hexobarbital metabolism are found in intoxication with Hg, As, Bi and Sn salts. The definitely lower hexobarbital level in the blood serum and brain at the waking moment, as well as the lower threshold hypnotic doses, suggest the interference of pharmacodynamic mechanisms at the level of the central nervous system in the prolongation of hexobarbital sleep after acute intoxication with CuSO4, CdSO4 and NiSO4.

Acute Disease↗
PubMed1976

Electromyographic changes in automechanics with increased heavy metal levels.

Twenty automechanics possessing increased whole blood values of one or more of the following heavy metals; chromium, copper, lead, manganese and nickel, were studied for peripheral nerve affection by means of electromyography (both sensoric and motoric nerve potentials were recorded). The heavy metal contents were related to the findings of denervation, distal motor latency, distal sensory latency, motoric and sensoric conduction velocities. Apart from two workers, in whom only lead was assayed, the remaining group of 18 were assayed for all heavy metals under study. Six workers showed increased distal motor and/or sensory latency and seven decreased nerve conduction velocity (four motoric and three sensoric affections). Of the workers with nerve affection, three showed increased levels of lead (nickel and chromium also raised). Four workers showed increased lead, nickel and chromium and one of lead, chromium and manganese. All in all, 10 out of 20 workers (50 percent) with elevated lead levels showed definite signs of peripheral neuropathy and seven out of 14 with raised nickel values showed these signs but they could all be accounted for by the increased lead levels. All except seven workers with raised lead levels in the whole group showed values above the critical limit of 80.0 mug/100 ml in whole blood. The data argue for the highly toxic effect of lead and other heavy metals on the peripheral nervous system and stress the diverse toxic exposure which automechanics undergo during their work. The possibility of there being a synergistic action between heavy metals and components of mineral oil and petroleum is discussed.

Action Potentials↗
PubMed1976

Heavy metal levels and delta-amino-levulinic acid dehydrase levels in peripheral polyneuropathy.

On the basis of assay of heavy metals in whole blood (lead, cadimum, chromium, copper, nickel and manganese) and delta-amino-levulinic-acid dehydrase (ALA-D) and ALA in urine in a normal Danish population, the levels of these clinco-chemical factors were assayed in 23 patients with peripheral neuropathy of unknown etiology. All patients studied showed electro-physiological sign of denervation and/or reduced motor or sensoric nerve conduction velocity. Cadmium and manganese were never found to be increased. In all but four patients, an increase of one or more heavy metals was found. Ten patients showed raised levels of two or more metals, the dominant metal being lead (10 cases), nine patients showed increased in chromium. A significant corrleation was found between increasing lead levels and decreasing ALA-D activity. Although normal concentrations of manganese were found, correlation analysis revealed a significant correlation between increased manganese and decreased ALA-D. The raised values of heavy metals could not be traced to occupational or other exposure to heavy metals and the increased values were not related to tobacco consumption. The findings are discussed in relation to known data on neuropathy and the results seem to indicate a multifactorial patholgenesis of the disease. Among factors contributing to the precipitation of the syndrome may be raised levels of heavy metals.

Adult↗
PubMed2026

Heavy-metal stress shapes habitat-specific microbial survival strategies in estuarine environments.

Estuarine ecosystems face increasing heavy metal pollution from rapid urbanization and industrialization, yet the microbial adaptive strategies to multiple metal stressors across different habitats remain poorly understood. This study investigated the diversity and composition of bacterial and fungal communities across free-living (FL), particle-attached (PA), and sediment (SE) fractions from three estuaries with varying heavy metal contamination, and further investigated functional adaptations of bacterial communities. High-throughput amplicon sequencing revealed habitat-specific communities, with SE hosting the highest alpha diversity and enrichment of metal-resistant genera such as Woeseia and Sva1033. Environmental filtering, particularly by Zn, was the dominant driver shaping bacterial assemblages across all habitats, whereas fungal communities displayed greater stochastic assembly patterns. Analysis of 44 high-quality bacterial metagenome-assembled genomes (MAGs) revealed diverse metal resistance genes (cusA, znuB, and zntA), along with enriched metabolic pathways for carbon, nitrogen, and sulfur cycling. Notably, both active efflux/oxidative stress defense and indirect immobilization mechanisms were observed across all habitats, but their relative importance differed: FL and PA communities exhibited a greater reliance on active metal efflux (czcAB) and oxidative stress defense (trxAB) to maintain intracellular homeostasis, whereas SE communities displayed a stronger genomic potential for sulfate reduction (dsrAB) that may contribute to metal immobilization through sulfide precipitation. This metabolic partitioning highlights the complementary roles of different habitats in mediating metal toxicity and biogeochemical cycling, providing new insights into microbial resilience in polluted estuaries and underscoring the urgency of addressing heavy-metal contamination in these critical ecosystems.

Estuaries↗
PubMed1977

Production of copper coproporphyrin III by Bacillus cereus. II. Regulation of the biosynthesis of coproporphyrin III and its copper complex by oxygen and heavy metal ions.

The effects of oxygen and heavy metal ions on the production of copper coproporphyrin III were studied in Bacillus cereus strain 2. The formation of copper coproporphyrin III was found to be maximum when the cells were cultivated in G-medium at a low level of oxygen supply, but it was suppressed at extremely low oxygen supply levels. When the cells were cultured in metal-free G-medium, neither metal-coproporphyrin III nor coproporphyrin III was formed. In the presence of copper in the medium (400-100 micrometers), the formation of coproporphyrin III copper salt was maximum, but the addition of various heavy metal ions other than copper to the copper-free medium resulted in the formation of neither coproporphyrin III nor its metal chelates. Copper ions appear to be specifically required for coproporphyrin III formation.

Bacillus cereus↗
PubMed2025

Partners in root nodule symbiosis respond uniquely to heavy metal stresses in a host genotype-dependent manner.

The mutualistic symbiosis between legume roots and soil rhizobia culminates in the formation of root nodules, where nitrogen is fixed. Root nodule symbiosis is inhibited by heavy metal stress. In this study, we investigated the relative responses of the symbiotic partners to a non-essential heavy metal cadmium (Cd) and an essential heavy metal zinc (Zn) stress and identified patterns in gene expression. We performed dual transcriptomics in nodules, using the Medicago truncatula-Sinorhizobium meliloti symbiotic system. Phenotypes were measured in the wild-type Medicago truncatula and a mutant in an ABC transporter gene (Mtabcg36), which showed compromised nodule formation in control conditions and further after heavy metal treatment. We observed that the rhizobia were particularly sensitive to Zn in mutant nodules. The greatest degree of differential gene expression in the host plant were observed under Cd and Zn treatments in wild-type nodules. Most Cd-regulated host genes were also differentially regulated by Zn, revealing little discernment between an essential and a non-essential ion under increased exposure. Furthermore, the host response to both the stresses affected auxin and iron homeostasis genes in a host genotype-dependent manner. Our results suggested impaired cadmium export from the mutant nodules. These results have potential implications in agricultural management systems and bioremediation strategies.

Symbiosis↗
PubMed2026

Heavy metal stress in native plant species: investigating phytoremediation potential through physiological and ISSR/SCoT molecular assessments.

In emerging countries, increased industrial activity has a significant impact on economic growth and urban development. However, the acceleration of industrial processes is accompanied by the release of contaminants such as heavy metals. According to the World Health Organization, one-fourth of all human diseases are caused by environmental contaminants, including heavy metals, which can impair numerous organs such as the neurological system, liver, and reproductive systems. This increased efforts to find effective and sustainable methods to remove heavy metals. Phytoremediation is an environmentally benign method of removing heavy metals using specific plants. Thus, from industrially contaminated locations, common native plant species of Lactuca serriola, Sisymbrium irio, Chenopodium murale, and Cynanchum acutum were selected for this study to assess the mechanisms of their molecular and physiological tolerance. Soil and plants were tested for heavy metals (Cd, Pb, and Cu), and contaminated locations were classified as low and highly polluted. Measurements were made of soluble sugar, protein, secondary metabolites, malondialdehyde, and H2O2. Additionally, inter simple sequence repeat (ISSR), start codon targeted (SCoT), and genomic template stability GTS were used. In heavily polluted areas, all plant species exhibit elevated amounts of sugar, proteins, H2O2, MDA, and secondary metabolites, while total phenolics showed a unique significant interaction (plant-location), where Cynanchum exhibited a hyper-stress phenolic accumulation to cope with toxicity, whereas Chenopodium maintained genomic stability with balanced phenolic level. Based on these findings, both Cynanchum acutum and Chenopodium murale demonstrate superior potential for phytoremediation and warrant further investigation for ecological restoration.

Heavy metal↗
PubMed1979

[The levels of heavy metals (Cd, Cu, Hg, Ni, Pb, Zn) in brook trouts from the River Leine in the area of Göttingen (West Germany) (author's transl)].

In order to evaluate the load of heavy metals (Cd, Cu, Hg, Ni, Pb, Zn) imposed on the River Leine by the city of Göttingen (medium-sized town) the content of heavy metals in fish samples (which had been collected at two points on the River Leine, upstream, respectively downstream of Göttingen--Fig. 1) were determined by Atomic Absorption Spectroscopy. Analysis of heavy metals in brook trout (total fish, flesh, and liver) showed a statistically significant definite increase in some heavy metals, caused by the sewage from the city of Göttingen. In the flesh only Cd in the liver Cd, Hg and Zn and in the total fish Cd, Cu and Zn had been increased significantly. All the values of heavy metals in the flesh were lower than the suggested maximum allowable concentrations.

Animals↗