Effects of environmental metal and metalloid pollutants on plants and human health: exploring nano-remediation approach.

Metal and metalloid pollutants severely threatens environmental ecosystems and human health, necessitating effective remediation strategies. Nanoparticle (NPs)-based approaches have gained significant attention as promising solutions for efficient removing heavy metals from various environmental matrices. The present review is focused on green synthesized NPs-mediated remediation such as the implementation of iron, carbon-based nanomaterials, metal oxides, and bio-based NPs. The review also explores the mechanisms of NPs interactions with heavy metals, including adsorption, precipitation, and redox reactions. Critical factors influencing the remediation efficiency, such as NPs size, surface charge, and composition, are systematically examined. Furthermore, the environmental fate, transport, and potential risks associated with the application of NPs are critically evaluated. The review also highlights various sources of metal and metalloid pollutants and their impact on human health and translocation in plant tissues. Prospects and challenges in translating NPs-based remediation from laboratory research to real-world applications are proposed. The current work will be helpful to direct future research endeavors and promote the sustainable implementation of metal and metalloid elimination.

Biogeochemical and microscopic studies of soil and Phragmites australis (Cav.) Trin. ex Steud. plants affected by coal mine dumps.

Developed areas of the coal industry are subjected to long-term anthropogenic impacts from the input and accumulation of overburdened coal material, containing potentially toxic heavy metals and metalloids (HMM). For the first time, comprehensive studies of soils and plants in the territory of the Donetsk coal basin were carried out using X-ray fluorescence, atomic absorption analysis, and electron microscopy. The observed changes in the soil redox conditions were characterized by a high sulfur content, and formations of new microphases of S-containing compounds: FeS2, PbFe6(SO4)4(OH)12, ZnSO4·nH2O, revealed the presence of technogenic salinization, increased Сorg content, and low pH contents. Exceedances of soil maximum permissible concentrations of Pb, Zn, Cu, and As in areas affected by coal dumps were apparent. As a consequence of long-term transformation of the environment with changes in properties and chemical pollution, a phytotoxic effect was revealed in Phragmites australis (Cav.) Trin. ex Steud, accompanied by changes in ultrastructural and organization features of roots and leaves such as increases in root diameters and thickness of leaf blades. The changes in the ultrastructure of cell organelles: a violation of the grana formation process, an increase in the number of plastoglobules, a decrease in the number of mitochondrial cristae, and a reduction in the electron density of the matrix in peroxisomes were also observed. The accumulation of large electron-dense inclusions and membrane fragments in cell vacuoles was observed. Such ultrastructural changes may indicate the existence of a P. australis ecotype due to its long-term adaptation to the disturbed environment.

Uncharted risk measures for the management of sustainable mining.

Governments commit to ensuring the welfare of their citizens by drafting and enforcing regulations that ultimately ensure the sustainability of mining. This study contributes to improving the sustainability of mining throughout the mine's lifecycle until the final destination of the mining products. We propose recommendations that address the sustainability of mining from a global perspective, framed around the United Nations Sustainable Development Goals (SDGs), following waste hierarchy with Common Agricultural Policies, and policies from the Green Deal on climate, energy, transport, and taxation. Tailings are the most significant source of environmental impact in mining operations and, therefore, must comply with controlling regulations through Tailings Management Facilities (TMFs). However, there have been several mining accidents involving TMFs worldwide. The recommendations begin during planning, preconstruction, and construction with practices such as fair consultations, tax revenue fairness, and mandatory insurance. The operation and management support parallel industries to mining and supporting health and education. Emergency planning involves the surrounding communities in mock drills and environmental monitoring. In the closure and rehabilitation, remediation technologies such as phytoremediation, carbon sequestration incentives, and biomass valorization are recommended. Finally, supporting a circular economy by prioritizing ethical consumption, resource reduction, material recovery, and replacing toxic minerals and materials from the start with "benign by design" is recommended. The strategies involve stakeholders directly or indirectly related to the mining companies' contamination and demonstrate a commitment to the SDGs, offering a holistic perspective on scientific, social, and regulatory issues. Integr Environ Assess Manag 2023;19:949-960. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Phytoremediation of copper-contaminated soil by Artemisia absinthium: comparative effect of chelating agents.

Phytoremediation is a promising method for the removal of toxic trace elements, specifically of copper, from the contaminated soil in the mining regions of Armenia. Thereby, the objectives of our study were the assessment of copper accumulation capacity and phytoremediation suitability of wormwood (Artemisia absinthium L.), a potential metal hyperaccumulator, as well as the identification of the influence of some chelating agents and their combinations on copper phytoremediation effectiveness. The results of studies have shown that A. absinthium is a relatively well-adapted plant species with the ability to grow in copper-contaminated soils collected from the surroundings of Zangezur Copper and Molybdenum Combine (south-east of Armenia). The observed decrease in plant growth in contaminated soil was possible to restore by the use of ammonium nitrate. It was revealed that for the remediation of copper-contaminated soils by phytostabilisation method, A. absinthium could be grown without the application of chelating agents, as being a perennial herb, it is able to accumulate relatively high contents of copper in its root and do not transfer this metal to the above-ground part at the same time. As opposed to the phytostabilisation method, for the cleaning of copper-contaminated soils through phytoextraction method by A. absinthium, the application of chemical amendments is needed for the enhancement of copper bioavailability and for its intensive transportation to the above-ground part of the plant. Collating the effects of various chemical agents on the plant, we concluded that the growth scheme, when the application of NH4NO3, a promoter of plant growth, is combined with the joint use of citric and malic acids, can be applied as the most expedient approach for remediation of copper-contaminated soils by phytoextraction method.

Influence of soil pollution on the morphology of roots and leaves of Verbascum thapsus L.

The impact of inorganic pollutants in the zone of industrial wastewater settling tanks (South of Russia) was studied. The levels of Mn, Cr, Ni, Cu, Zn, Pb, Cd were determined for Verbascum thapsus L., which are part of the mesophilic succession of wild plants in the studied technogenically polluted territory. The bioavailability of heavy metals (HM) for plants from transformed soils has been established. Anatomical and morphological features in the tissues of the plants affected by HM were analyzed using light-optical and electron microscopic methods. Contamination of the soil cover with Mn, Cr, Ni, Cu, Zn, Pb and Cd has been established with maximum content of Zn. It was revealed that the HM content in the V. thapsus plants exceeded the maximum permissible levels (Russian state standard): Zn by 23, Pb by 2, Cr by 31 and Cd by 3 times. The lower level of HM content in the inflorescences of mullein plants in comparison with the root system, stems and leaves indicates the resistance of generative organs to technogenic pollution. In the root and leaves of the V. thapsus, the anatomical and ultrastructural observation were carried out using light-optical and transmission electron microscopy. Changes in the ultrastructure of plants under the influence of anthropogenic impact have been revealed. The most significant changes of the ultrastructure of the polluted plants were found in the cell organelles of leaves (mitochondria, plastids, peroxisomes, etc.) including spatial transformation of the thylakoid system of plastids during the metal accumulation by plants, which may determine the mechanism of plant adaptation to technogenic pollution.

The identification of phytoextraction potential of Melilotus officinalis and Amaranthus retroflexus growing on copper- and molybdenum-polluted soils.

The contamination of soils by heavy metals from the mining industry nowadays is one of the greatest threats to environment and human health. The cleaning of polluted soils using cost-effective and eco-friendly methods such as phytoextraction has wide public recognition. Considering the above-mentioned ones, the objectives of the present study were the identification of Cu and Mo accumulation capability and the phytoextraction potential of Melilotus officinalis and Amaranthus retroflexus as well as the determination of the influence of ammonium nitrate and EDTA on phytoextraction effectiveness. The contaminated soil samples for phytoremediation experiments under ex situ conditions were collected from the surroundings of the Zangezur Copper and Molybdenum Combine, Armenia. During the studies, it was found out that M. officinalis and A. retroflexus are capable of growing in polluted soils. M. officinalis grown in polluted soil had greater ability to accumulate heavy metals in roots, while the ability to transport the copper to aboveground parts was more pronounced in A. retroflexus. During the growing of these plant species for phytoextraction of soils contaminated by copper, it is necessary to use chelates, in particular the EDTA, for the enhancement of the effectiveness of phytoextraction process. EDTA due to chelating influence increased the availability of copper for plants and its mobility in them that lead to greater accumulation of this metal in shoots. The application of chelates did not have a significant impact on molybdenum accumulation intensity in plants; therefore, in case of this metal, it is unreasonable to use additional chelating compounds.

ZnO and CuO nanoparticles: a threat to soil organisms, plants, and human health.

The progressive increase in nanoparticles (NPs) applications and their potential release into the environment because the majority of them end up in the soil without proper care have drawn considerable attention to the public health, which has become an increasingly important area of research. It is required to understand ecological threats of NPs before applications. Once NPs are released into the environment, they are subjected to translocation and go through several modifications, such as bio/geo-transformation which plays a significant role in determination of ultimate fate in the environment. The interaction between plants and NPs is an important aspect of the risk assessment. The plants growing in a contaminated medium may significantly pose a threat to human health via the food chain. Metal oxide NPs ZnO and CuO, the most important NPs, are highly toxic to a wide range of organisms. Exposure and effects of CuO and ZnO NPs on soil biota and human health are critically discussed in this study. The potential benefits and unintentional dangers of NPs to the environment and human health are essential to evaluate and expected to produce less toxic and more degradable NPs to minimize the environmental risk in the future.

Copper phytoremediation potential of wild plant species growing in the mine polluted areas of Armenia.

Nowadays the pollution of soil by trace metals from the mining industry is one of the biggest threats to ecosystems and human health. In this study, sixteen native wild plant species growing in Cu contaminated soils of mining region in Armenia were investigated to reveal their phytoremediation potential for restoration of soils in this area. During the investigation soil main characteristics affecting the Cu accumulation capability of plants were also determined. In roots (dry weight) of dominant plant species growing in Cu contaminated areas the content of copper varied between 55 mg/kg (Hypericum perforatum) and 775 mg/kg (Thymus kotschyanus), and in shoots of plants - in the range from 33 mg/kg (Teucrium orientale) to 243 mg/kg (Phleum pratense). Since the Cu accumulation capability of plants depends both on physiological peculiarities of plants and on the content of Cubioavailable in the soil, the studies were carried out in this direction and it was found that the high contents of organic matter and clay in the soil facilitated the decrease of the ratio Cubioavailable/Cutotal and as a result - the decrease of Cu accumulation capability of plants. Thymus kotschyanus, Phleum pratense, and Achillea millefolium had the highest phytostabilization potential from all studied plant species due to high bioconcentration factor of root (BCFroot) and low translocation factor (TF) values registered in these plants, and further field and laboratory experiments are planned to confirm this useful ability. The detection of phytoremediation potential of wild plant species growing in areas polluted by trace metals will enable us to use eco-friendly and cost-effective remediation methods, utterly required to clean up the soils in the mining regions of Armenia.

Geochemistry of Potentially Toxic Trace Elements in Soils of Mining Area: A Case Study from Zangezur Copper and Molybdenum Combine, Armenia.

Research was carried out to determine and asses the influence of mining industries on soil contamination with application of various pollution indices. For soil sampling 13 points were selected. Soil samples were analyzed for heavy metals by AAS. Eleven elements were determined and the greater quantities were generally observed in case of Mo and Cu. During the testing of soil pollution level pollution load index, degree of contamination (Cd) and geoaccumulation index were used. The correlation analysis revealed the strongest positive correlation between molybdenum and copper and that the high content of mentioned elements in soil was caused by mining industry. Assessment based on Cd showed that the 33.3% of A horizon soil samples referred to a very high degree of pollution. Obtained results will be useful for implementation of control measures of pollution and the remediation techniques.