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The fragmented and complex topography of mountainous plateau basins resulted in significant regional differences at the watershed scale in soil physicochemical properties, soil texture and soil types, etc. Due to the large watershed range, high altitude, and high sampling difficulty, there was relatively little research on the background values of soil environment in mountainous plateau areas. The purpose of this study was to determine the environmental background values of soil and explore the main environmental controls for the Bijiang Basin in Southwest China. The environmental background value of soil Pb and Zn in the Bijiang River Basin was 30.73 mg·kg-1 and 64.85 mg·kg-1, respectively. The value was mainly affected by altitude, soil type, pH and organic matter. The research results had certain reference value for the selection of background values for regional pollution assessment on soil or sediment in mountainous areas. [ABSTRACT FROM AUTHOR]

Heavy metal pollution seriously threatens the drinking water safety and ecological environment in karst lead–zinc mines. Fifteen groundwater and surface water samples were collected in a karst lead–zinc mine in Daxin, Chongzuo. Ten heavy metal (Mn, Zn, As, Pb, Cr, Cd, Ni, Co, Cu, and Fe) concentrations were detected. Correlation and cluster analysis were utilized to explore the distribution characteristics and sources. The health risks were appraised using the health risk assessment model. The groundwater had more heavy metal types than the surface water, of which the concentrations and average concentrations exceeded the class III water quality standard. The mine drainage contributed most (65.10%) to the heavy metal concentrations. Pb, Zn, Cd, Mn, Co, Ni, Cu, and Fe primarily originated from the mining of the lead–zinc mine, Cr primarily came from the fuel combustion and wear of metals, and As was primarily connected with the regional geological background. The groundwater had a higher total health risk (5.12 × 10−4 a−1) than the surface water (2.17 × 10−4 a−1). In comparison with the non-carcinogenic risk, the carcinogenic risk increased by three to five orders of magnitude. The carcinogenic risk distribution of Cr and Cd represented the health risk pattern. The drinking pathway posed two to three orders of magnitude the amount of health risks that the dermal contact pathway posed. Children suffered greater health risks. Water security for children should be more strictly controlled. Zn, Cd, Pb, Mn, and Cr must be paid more attention in terms of water quality protection and management. [ABSTRACT FROM AUTHOR]

The article discusses spatiotemporal changes in the main climatic indicators in the period 1941- 2020, their impact on the possibilities of the atmospheric self-purification of a lead-zinc mine. The study of changes in air temperature showed the presence of long-term trends, and the climatic potential parameters of the dissipative capacity of the mine atmosphere were calculated. It was found that the average monthly air temperature increases with the rate of warming of 0.19 to 0.34 °C every 10 years. Moreover, a relatively greater increase in temperature occurs in winter, and a smaller increase in summer. Determined that the anomalous air temperature field is large in the study area both in winter and summer months. Based on the calculations, data on the spatiotemporal variability of the climatic potential of the dissipation capacity and the coefficient of atmospheric self-purification were obtained. This made it possible to establish that throughout the entire annual cycle, unfavorable conditions are observed for the dispersion of polluting particles in the atmospheric air, and to a greater extent during the cold period of the year. The results indicate the manifestations of natural and anthropogenic atmospheric processes that prevent the dispersion of pollution in the atmosphere. The performed research is significant for the practical use. Since data on the spatial and temporal variability of the dispersion potential of atmospheric air must be previously assessed when implementing measures to manage air quality in an industrial region. [ABSTRACT FROM AUTHOR]

Improper mining waste and tailing management in Pb-Zn mining areas (Balya and Koru) in the north-west Türkiye have not been researched sufficiently. Accordingly, concentrations of heavy metal were determined in mine tailing and soils taken from Balya and Koru, and a health risk evaluation caused by heavy metals was performed. Average Cd, Cr, Cu, Mn, Ni, Pb, and Zn concentrations in mine tailings in Balya are 35.2, 17.8, 354.7, 1735, 10, 10089, 3730 mg kg-1 and these values were determined as 9.9, 8.9, 101.5, 1308, 4.5, 1871, 1375 mg kg-1 in the tailings in Koru, respectively. The concentrations of heavy metals in the soil samples taken from both Balya and Koru were determined to be lower. The evaluation of heavy metals' health risks was performed according to both non-carcinogenic and carcinogenic effects. The primary route of heavy metals in adults and children has been determined by oral intake. For both children and adults, the order of the carcinogenic effects of heavy metals in mine tailings and soils in Balya and Koru was Cd > Pb > Ni > Cr. As the carcinogenic risk values of Cd and Pb for adults and children in mine tailing and soils in Balya were above the limit value, the children's Cd carcinogenic risk values were found above the limit value in mine tailing and soils in Koru. The mining area in both Balya and Koru poses a risk to human health since it is close to settlements. [ABSTRACT FROM AUTHOR]

Heavy metal pollution seriously threatens the drinking water safety and ecological environment in karst lead–zinc mines. Fifteen groundwater and surface water samples were collected in a karst lead–zinc mine in Daxin, Chongzuo. Ten heavy metal (Mn, Zn, As, Pb, Cr, Cd, Ni, Co, Cu, and Fe) concentrations were detected. Correlation and cluster analysis were utilized to explore the distribution characteristics and sources. The health risks were appraised using the health risk assessment model. The groundwater had more heavy metal types than the surface water, of which the concentrations and average concentrations exceeded the class III water quality standard. The mine drainage contributed most (65.10%) to the heavy metal concentrations. Pb, Zn, Cd, Mn, Co, Ni, Cu, and Fe primarily originated from the mining of the lead–zinc mine, Cr primarily came from the fuel combustion and wear of metals, and As was primarily connected with the regional geological background. The groundwater had a higher total health risk (5.12 × 10−4 a−1) than the surface water (2.17 × 10−4 a−1). In comparison with the non-carcinogenic risk, the carcinogenic risk increased by three to five orders of magnitude. The carcinogenic risk distribution of Cr and Cd represented the health risk pattern. The drinking pathway posed two to three orders of magnitude the amount of health risks that the dermal contact pathway posed. Children suffered greater health risks. Water security for children should be more strictly controlled. Zn, Cd, Pb, Mn, and Cr must be paid more attention in terms of water quality protection and management.

Hyperspectral reflectance of soil can be used to effectively estimate the status of heavy metal pollution in soil. This study aims to better investigate the soil heavy metal information reflected by spectra. Quantitative comparisons were performed on the advantages and adaptability of different spectral preprocessing, feature selection, and modeling. Optimal inversion models were constructed for the rapid hyperspectral estimation of soil quality in the lead-zinc mining areas with multi-heavy metal pollution. 100 soil samples at 0-30 cm depth were also collected from the lead-zinc mining area in Laiyuan County, Baoding City, Hebei Province, China. The contents of Cu, Cr, Ni, Zn, Cd, and Pb were analyzed in these soil samples. The pollution status of heavy metals in the study area was assessed using the Nemerow pollution index and potential ecological risk index. The raw hyperspectral reflectance of soil samples was measured by the standard procedure with a spectrometer of SVC HR-1024 under laboratory conditions. Firstly, Savitzky-Golay smoothing (SG) was applied to the soil spectral data, where the SG-smoothed spectra were marked as the original spectra (OR). Secondly, three mathematical transformations were applied to the original spectra (OR), including multiple scatter correction (MSC), standard normal variate (SNV), and reciprocal logarithm (LR). Each transformed spectrum was then subjected to the first-order derivative (FD) and second-order derivative (SD) transformations. Thirdly, the different pre-processing spectra were filtered by the correlation coefficient study (PCC) and Boruta algorithm for the feature bands. Then the heavy metal content was analyzed using partial least squares regression (PLSR) and various machine learning models, including random forest (RF), extreme gradient boosting (XGBoost), support vector machine (SVM), gaussian process regression (GPR), and backpropagation neural network (BPNN). The accuracy of the estimation model was evaluated to compare the coefficient of determination (R² ), root mean square error (RMSE), and relative percent difference (RPD) between the prediction and validation values. The optimal models were selected after optimization. The results indicated that: 1) The soil Cr and Ni were non-contaminated in the study area, whereas, Cu, Zn, Cd, and Pb showed varying degrees of pollution, with the more severely affected Zn and Cd. Compared with the local soil heavy metal background values, the mean Nemerow pollution index was 29.71, indicating heavy pollution. Meanwhile, the mean potential ecological risk index was 1 330.3, indicating the high ecological risk state. Overall, there was the multi-heavy metals compound pollution with the high ecological risk. 2) Spectral differentiation yields favorable results but is susceptible to noise interference, whereas techniques such as multiple scatter correction, standard normal variate, and reciprocal logarithm transformations can be employed for spectral denoising, thereby enhancing overall processing performance. 3) In feature extraction, the correlation coefficient was Rmax² =0.81 and Rmin² =0.44, in order to extract the larger number of bands with the precision metrics for the heavy metal inversion models. By contrast, the Boruta algorithm was used to extract the fewer feature bands, corresponding to the model precision metrics of Rmax² =0.76 andRmin² =0.51. A comparative analysis revealed that the Boruta algorithm was achieved in the more stable performance of model prediction, in order to minimize the optimal combination of feature bands. 4) BPNN and XGBoost demonstrated better capabilities to represent the nonlinear relationship between heavy metal content and spectra. BPNN was achieved optimal inversion for Cr (R² =0.81, RPD=2.37), Ni (R² =0.76, RPD=2.08), and Zn (R² =0.69, RPD=1.85). XGBoost was achieved optimal inversion for Pb (R² =0.76, RPD=2.08), and Cd (R² =0.68, RPD=1.81). SVMR was achieved in the optimal inversion for Cu (R² =0.58, RPD=1.58). The different spectral preprocessing, feature selection, and modeling posed a significant impact on the inversion of soil heavy metal content. Optimal preprocessing and modeling can be expected to effectively enhance the accuracy of inversions. This research can provide a strong reference for further efficient, accurate, and large-scale remote sensing monitoring of soil heavy metal pollution, particularly for soil remediation and treatment in lead-zinc mining areas. [ABSTRACT FROM AUTHOR]

Understanding the characteristics of lead–zinc mine occurrences and mastering effective investigative techniques are paramount in modern ore prospecting. This research focuses on the forested region of Yichun city in China, with a specific emphasis on the strategic mineral resource of a lead–zinc mine. The study examines the distribution patterns of this mineral and employs advanced aeromagnetic exploration methods. Firstly, we analyzed the geological structure and features of the region by leveraging the latest high-precision aeromagnetic data collected using dynamic delta wing technology. This analysis was complemented by an assessment of the geological conditions of the research area, existing lead–zinc deposits, ground magnetic surveys, and verification studies. With the goal of establishing a meaningful correlation between aeromagnetic anomalies and lead–zinc deposits, we employed various potential field conversion techniques, including the reduction to the pole, vertical derivatives, upward continuation, and residual anomaly analysis techniques. Secondly, we investigated the metallogenic sites within this region and provided a comprehensive summary of the metallogenic circumstances and characteristics related to aeromagnetic prospecting. Thirdly, we employed human–computer interaction fitting inversion techniques to predict the potential for lead–zinc mine prospecting in areas exhibiting aeromagnetic anomalies. The study underscores the significance of high-amplitude and large-scale aeromagnetic anomalies in the study area. Furthermore, we examined the interplay between intrusive rocks, strata, and structural elements within the region to identify favorable conditions for lead–zinc mineralization. As a result of our analysis and discussions, a location was predicted where a lead–zinc mine may exist. The research methodology outlined in this article provides valuable insights for future lead–zinc mine exploration efforts in areas characterized by similar geological conditions. [ABSTRACT FROM AUTHOR]

At present, the pollution of arsenic (As) and lead (Pb) is becoming increasingly serious. The pollution caused by the release of As and Pb from lead–zinc mines has seriously affected the water and soil environment and threatened human health. It is necessary to reveal the release characteristics of As and Pb. The actual scene of mine drainage (MD) and rainwater (RW) leaching waste rocks is the one of the main reasons for the release of As and Pb. However, the leaching behavior of As and Pb in these waste rocks under MD and RW suffered from a lack of in-depth research. In this study, we investigated the occurrence of As and Pb in waste rocks (S1–S6) by using X-ray diffraction (XRD) and time-of-flight secondary ion mass spectrometry (TOF-SIMS), and then, the changes in As and Pb concentration and the hydrochemical parameter in leaching solution were systematically studied. Furthermore, the correlation between the release of As and Pb and mineral composition was also evaluated. Results showed that these waste rocks were mainly composed of carbonate and sulfide minerals. As and Pb were mainly bounded or associated with sulfide minerals such as arsenopyrite, pyrite, chalcopyrite, and galena in these waste rocks, and small parts of As and Pb were absorbed or encased by clay minerals such as kaolinite and chlorite. Under MD and RW leaching, the pH, redox potential (Eh), and electric conductivity (EC) of each waste rock tended to be consistent due to their buffering ability; the leachate pH of waste rocks with more carbonate minerals was higher than that of sulfide minerals. Both As and Pb were released most under MD leaching in comparison to RW, reaching 6.57 and 60.32 mg/kg, respectively, due to MD's low pH and high Eh value. However, As in waste rock released more under alkaline conditions because part of the arsenic was in the form of arsenate. As and Pb release were mainly positively correlated with the proportions of sulfide minerals in these waste rocks. MD leaching significantly promoted the release of As and Pb from waste rocks, which would cause a great threat to the surrounding environment, and control measures were imperative. This paper not only reveals the As and Pb pollution mechanism around the lead–zinc mining area but also provides a theoretical basis for the prevention and control of As and Pb pollution in the future. [ABSTRACT FROM AUTHOR]

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

The root-associated microbiome assembly substantially promotes (hyper)accumulator plant growth and metal accumulation and is influenced by multiple factors, especially host species and environmental stress. Athyrium wardii (Hook.) is a phytostabilizer that grows in lead (Pb)-zinc (Zn) mine tailings and shows high root Pb accumulation. However, there remains little information on the assembly of the root-associated microbiome of A. wardii and its role in phytostabilization. A field study investigated the structural and functional variation in the root-associated bacterial microbiome of Athyrium wardii (Hook.) exposed to different levels of contamination in Pb-Zn mine tailings. The root compartment dominated the variation in the root-associated bacterial microbiome but the levels of contaminants showed less impact. Bacterial co-occurrence was enhanced in the rhizosphere soil and rhizoplane but tended to be much simpler in the endosphere in terms of network complexity and connectivity. This indicates that the microbial community assembly of A. wardii was non-random and shaped by root selective effects. Proteobacteria, Chloroflexi, Actinobacteria, Cyanobacteria, and Acidobacteriota were generally the dominant bacterial phyla. The genera Crossiella and Bradyrhizobium were enriched in the rhizosphere and cyanobacterial genera were enriched in the endosphere, demonstrating substantial advantages to plant survival and adaptation in the harsh mine environment. Functional categories involved in amino acid and carbohydrate metabolism were abundant in the rhizosphere soil, thus contributing to metal solubility and bioavailability in the rhizosphere. Membrane transporters, especially ATP-binding cassette transporters, were enriched in the endosphere, indicating a potential role in metal tolerance and transportation in A. wardii. The study shows substantial variation in the structure and function of microbiomes colonizing different compartments, with the rhizosphere and endophytic microbiota potentially involved in plant metal tolerance and accumulation during phytostabilization.

The stress background and rock fractures are essential factors affecting the stability of mines. In order to better understand the in situ stress background and rock fractures in the Guangdong Fankou Mine, we use ultrasonic borehole television scanning to measure rock fractures. The results indicate that rock fractures are intensively distributed at depths of −360 m to −450 m below the surface, suggesting the effect of intensive mining activities. The present maximum horizontal principal stress direction is NWW, which is consistent with the regional tectonic stress field direction. Systematic measurement of rock fractures is fundamental for further three-dimensional geological modeling and is significant for mining engineering.

Mining activities tend to generate various waste including tailings, waste water and waste rock. Efficient management and disposal of these waste materials are critical to minimize their environmental impact and ensure the sustainable operation of mining activities. A huge number of tailings are produced all around the world each year. Generally, part of the tailings is used for underground backfilling and another part is discharged to the tailings dam. The former can provide underground support while the latter tends to cause some environmental problems because the tailings are generally mixed with some chemicals. Regarding this, enhancing the circular use of tailings is crucial to guarantee the sustainable mining engineering. In this study, the feasibility of using fine-grained tailings to make non-burning hollow bricks for underground windbreaks is investigated. A two-stage experiment was implemented where the first stage experiment indicated the threshold of water content, the ratio of cement and tailings and the ratio of fine-grained and rod-mill tailings. In addition, it can be indicated that the addition of polyethylene fibers would increase the compressive strength of hollow bricks in some extent. The second-stage experiment was conducted with no rod-mill tailing added and it can be found that when the ratio of cement and tailings is equal or higher than 1:6, fiber content is more significant in improving brick strength but when this value is lower, the ratio of cement is more important than fiber factors. When the ratio of cement and fine-grained tailings is 1:8 with 0.5 g/kg and 12 mm polypropylene fiber added, the hollow brick is capable of achieving strength of 1.4 MPa for 28 days curation with the price of 0.50 RMB/block. This proportioning scheme is the least expensive while meeting the strength of the windbreak wall for the Fan Kou lead–zinc mine. Finally, it can be indicated that the usage of fine-grained tailings to make underground windbreak wall is feasible and thus provide a new scenario to circular usage of tailings. In addition, other proportioning schemes proposed in this study perhaps can meet more engineering requirements so as to provide more alternatives for circular use of tailings.

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

Copyright of Nonferrous Metals (Mining Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The dumping of lead-zinc tailings causes serious environmental pollution around the mine. In order to study the safe dumping of tailings and the removal of a certain amount of heavy metals during the dumping process, the release and migration of Zn, Cd, Pb, Cu and As under different oxidant concentrations and different liquid to solid ratios were investigated in lead-zinc tailings of Lutang, Dachang, Guangxi. The results show that the oxidizing environment can effectively promote the release and migration of the elements. The higher the oxidant concentration, the more the elements can be migrated out. The optimum liquid-solid ratio for release and migration varies among the elements, with the most suitable solid to liquid ratio being 1∶10 for Zn and 1∶6 for Cd, 1∶6 for Pb, 1∶5 for Cu and 1∶6 for As.

Understanding the characteristics of lead–zinc mine occurrences and mastering effective investigative techniques are paramount in modern ore prospecting. This research focuses on the forested region of Yichun city in China, with a specific emphasis on the strategic mineral resource of a lead–zinc mine. The study examines the distribution patterns of this mineral and employs advanced aeromagnetic exploration methods. Firstly, we analyzed the geological structure and features of the region by leveraging the latest high-precision aeromagnetic data collected using dynamic delta wing technology. This analysis was complemented by an assessment of the geological conditions of the research area, existing lead–zinc deposits, ground magnetic surveys, and verification studies. With the goal of establishing a meaningful correlation between aeromagnetic anomalies and lead–zinc deposits, we employed various potential field conversion techniques, including the reduction to the pole, vertical derivatives, upward continuation, and residual anomaly analysis techniques. Secondly, we investigated the metallogenic sites within this region and provided a comprehensive summary of the metallogenic circumstances and characteristics related to aeromagnetic prospecting. Thirdly, we employed human–computer interaction fitting inversion techniques to predict the potential for lead–zinc mine prospecting in areas exhibiting aeromagnetic anomalies. The study underscores the significance of high-amplitude and large-scale aeromagnetic anomalies in the study area. Furthermore, we examined the interplay between intrusive rocks, strata, and structural elements within the region to identify favorable conditions for lead–zinc mineralization. As a result of our analysis and discussions, a location was predicted where a lead–zinc mine may exist. The research methodology outlined in this article provides valuable insights for future lead–zinc mine exploration efforts in areas characterized by similar geological conditions.

At present, the pollution of arsenic (As) and lead (Pb) is becoming increasingly serious. The pollution caused by the release of As and Pb from lead–zinc mines has seriously affected the water and soil environment and threatened human health. It is necessary to reveal the release characteristics of As and Pb. The actual scene of mine drainage (MD) and rainwater (RW) leaching waste rocks is the one of the main reasons for the release of As and Pb. However, the leaching behavior of As and Pb in these waste rocks under MD and RW suffered from a lack of in-depth research. In this study, we investigated the occurrence of As and Pb in waste rocks (S1–S6) by using X-ray diffraction (XRD) and time-of-flight secondary ion mass spectrometry (TOF-SIMS), and then, the changes in As and Pb concentration and the hydrochemical parameter in leaching solution were systematically studied. Furthermore, the correlation between the release of As and Pb and mineral composition was also evaluated. Results showed that these waste rocks were mainly composed of carbonate and sulfide minerals. As and Pb were mainly bounded or associated with sulfide minerals such as arsenopyrite, pyrite, chalcopyrite, and galena in these waste rocks, and small parts of As and Pb were absorbed or encased by clay minerals such as kaolinite and chlorite. Under MD and RW leaching, the pH, redox potential (Eh), and electric conductivity (EC) of each waste rock tended to be consistent due to their buffering ability; the leachate pH of waste rocks with more carbonate minerals was higher than that of sulfide minerals. Both As and Pb were released most under MD leaching in comparison to RW, reaching 6.57 and 60.32 mg/kg, respectively, due to MD’s low pH and high Eh value. However, As in waste rock released more under alkaline conditions because part of the arsenic was in the form of arsenate. As and Pb release were mainly positively correlated with the proportions of sulfide minerals in these waste rocks. MD leaching significantly promoted the release of As and Pb from waste rocks, which would cause a great threat to the surrounding environment, and control measures were imperative. This paper not only reveals the As and Pb pollution mechanism around the lead–zinc mining area but also provides a theoretical basis for the prevention and control of As and Pb pollution in the future.

China holds large-scale lead–zinc mineral resources; however, mining activities often cause severe contamination by heavy metals. This study systemically assessed contamination by eight heavy metals (Cu, Zn, Cd, Pb, Cr, Hg, Ni, and As) in mine tailings, soil, and groundwater from 27 contaminated sites across China. Regarding mine tailings, 1% of the mine tailing samples were hazardous waste and 20% were class II non-hazardous waste. Regarding soil, Zn and Pb showed the highest mean concentrations, at 5574.67 mg/kg and 2034.88 mg/kg, respectively. The indexes of geo-accumulation (Igeo) of eight heavy metals ranged from −3.62 to 7.67, while Zn, Pb, and Cd showed the highest environmental risk levels as the priority pollutants. The contamination levels of these heavy metals in groundwater were generally in the order of Zn>As>Pb>Ni>Cd>Cu>Hg>Cr. In this study, 20% of the soil and 10% of the groundwater samples exceeded the corresponding quality limits. The content of heavy metals in soil, groundwater, and mine tailing were positively correlated, demonstrating the main pollution source and transport paths. The pollution levels of heavy metals in soil and groundwater were listed in the foremost and moderate positions compared with similar sites from other countries, respectively. These results may help determine the pollution levels of lead–zinc mining regions and direct the remediation activities of target sites to support the environmental management of abandoned mining and tailing waste in China.

In this study, concentrations of Cr, Mn, Pb, Cu, Zn, As, Cd, Sb, and Fe were determined in soils of a Pb-Zn mine watershed in northern Guangxi, China, for ecological risk assessment and source analysis. The atomic fluorescence spectrometry and ICP-OES were used to determine concentrations of heavy metals (HMs), and the total amount of Mn, Cu, Zn, As, Cd, and Pb exceeded the limit. Among them, the weak acid extractable fraction (F1) state masses of Pb, Mn, and Zn accounted for a higher ecological risk. The study area was divided into three distinct areas: highest concentrations of HMs were distributed in front of the Sidi River mountain (1# and 2#) and at the subterranean river entrance (5# and 6#), followed by the area along the river and the irrigated area of the river (3# and 4#), and the central highlands and southwestern parts had low concentrations (7# and 8#). The ecological risk assessment results indicate Cd is of extremely high ecological risk, Pb and Mn are of medium minor ecological risk, Zn is of minor ecological risk, and the rest have almost no impact on the eco-environment. The source apportionment results showed that Cu, Zn, Cd, Sb, and Pb were mainly controlled by anthropogenic activities, such as mining; Cr, Fe, and As were mainly influenced by natural processes, such as soil-forming parent rocks; and Mn is jointly controlled by mining and soil-forming parent rocks. This study can provide scientific guidance and technical support for soil risk control or remediation in mining areas. [ABSTRACT FROM AUTHOR]

Mineral resources are non-renewable resources in nature, and their reserves are very limited. In order to maximize the exploitation of mineral resources and avoid unnecessary waste of mineral resources, it is imperative to mine pillars. However, with the exploitation of underground deposits, the influence of in-situ stress on mining work is inevitable, especially for pillar mining, and in-situ stress must be treated well during mining. Therefore, based on the current top and bottom pillar mining technology in the upper middle section of Fankou lead-zinc mine, this paper puts forward a new type of top and bottom pillar and corner residual ore mining technology in view of its shortcomings. The problems of mining efficiency, safety, dilution rate and loss rate existing in the previous mining technology have been solved. It improves the economic benefit of the mining area, and also provides an idea for the pillar mining scheme design of the same type of mine. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: The aims of this study were to investigate the status, spatial distribution, ecological risk, sources, and temporal accumulation of potentially toxic elements (PTEs) in stream sediments of the Hetaoping large lead–zinc polymetallic mine concentration area. Methods: In this study, 35 new collected (2017) and 12 achieved (the 1980s) stream sediments from the Hetaoping and Heiyanao stream drainages in the mine area were used. The geo-accumulation (Igeo), potential ecological risk ( E r i and PERI), sediment quality guidelines (SQGs), and mean probable effect concentration quotient (PECQ) were used to evaluate the status and ecological risk of PTEs. Correlation analysis, hierarchical clustering analysis, and enrichment factors (EF) were used to identify the potential source of PTEs. Kruskal–Wallis tests were analyzed to compare the significant difference of PTMs in different drainages and sampling periods. Results and discussion: Results showed that As, Cu, Hg, Pb, and Zn are obviously above their regional background values. As, Cd, Cu, Hg, Pb, and Zn are found at moderately contaminated to extremely contaminated levels near the Hetaoping and Maozhupeng deposits, as well as in the Heiyanao drainage. The ecological risk of As, Cd, Hg, and Pb is predominantly near the mining center. Cr and Ni are from natural sources; As, Cd, Cu, Pb, and Zn come from mining activities near the mining center, as well as natural sources outside the mining center, while Hg originates from other uncertain anthropogenic sources. Conclusions: Mining activities in the past 40 years have significantly increased As, Cd, Cu, Hg, Pb, and Zn concentrations and ecological risks in the surrounding stream sediments in the study area. [ABSTRACT FROM AUTHOR]

Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A total of 28,095 surface soil samples were collected in areas with high natural background levels; the potential ecological risk is generally low, and the high-risk area is small and mainly affected by lead–zinc mines. The contribution to the potential ecological risk factor (RI) is as follows: Hg > Cd > As > Pb > Cu > Ni > Cr > Zn, with noncarcinogenic chronic risks of Cr > As > Cd > Pb > Ni > Cu > Hg > Zn; furthermore, dermal contact is the main pathway of exposure causing health risks. The total carcinogenic risks caused by heavy metals were as follows: Cr > Cd > As > Pb; and the risks posed by Cr, Cd, and As were higher than the threshold value (1.0 × 10−4); people face a higher threat to heavy metals in soils in Zhenxiong, Ludian, Huize, Weixin, and Zhaoyang. The evaluation result of the EPA PMF model shows that the soil heavy metals are mainly composed of five sources, of which basalt, Permian, and Triassic carbonate rock parent material constitute the natural background source, while the mining activities of lead–zinc mines and the emissions of coal burning by residents constitute the anthropogenic source. The contribution was ranked in order of lead–zinc mining (26.7%) > Triassic carbonate (23.7%) > basalt (20.9%) > coal burning and automobile emissions (16.1%) > Permian carbonate (12.6%). [ABSTRACT FROM AUTHOR]

To investigate the contaminant characteristics of heavy metals in soils and vegetables surrounding a lead-zinc mine in Huize County, Yunnan Province, thirty surface soil samples and vegetable samples were collected to measure the contents of heavy metals, including lead (Pb), zinc (Zn), copper (Cu), and cadmium (Cd). The potential risk was evaluated by using the single factor pollution index, Nemerow comprehensive pollution index, and target hazard index. The results showed that the contents of Pb, Zn, Cu, and Cd in the soil were 954.1, 2236.5, 151.1, and 4.83 mg·kg−1, respectively. Compared with the soil background values in Yunnan Province, the soil surrounding the lead-zinc mine was polluted by Pb, Zn and Cd. The Nemerow comprehensive pollution index evaluation indicated that the soil was heavily polluted. The contents of Pb, Zn, Cu, and Cd in vegetables were 117.5–778.6, 430.3–2212.4, 16.8–89, and 1.28–34.3 mg·kg−1, respectively. Among them, the contents of Pb and Cd in vegetables exceeded the pollutant limit in food products of China's National Standard for Food Safety (GB 2762–2017). The contents of Pb, Zn and Cd in the soil were extremely significantly or significantly correlated with the contents of Pb, Zn and Cd in the edible parts of vegetables. The results indicated that there was serious heavy metal pollution and significant health risk for the soil and vegetables surrounding the lead-zinc mine. The research results not only reveal the contaminant characteristics of heavy metals in soils and vegetables surrounding a lead-zinc mine in Huize County, Yunnan Province, but also could provide a scientific evidence for reasonable utilization and ecological remediation. [ABSTRACT FROM AUTHOR]

The species composition of eight shrub communities were investigated in order to understand the species diversity of plant communities in buffer zone and wetland of Momianhe stream along a long-term mine waste area, Lanping county, Yunnan province, China. Dominant plant species and soil samples were collected to analysis heavy metal (Cu, Zn, Pb and Cd) accumulation characteristics. The results showed that 100% samples for Zn, Pb, Cd, and 87.5% samples for Cu in the investigated area exceeded the Yunnan geochemical background value of the heavy metals in the soil. There were 36 plants species in communities, among which Epilobium pyrricholophum, Elsholtzia argyi, Artemisia vestita, Tripogon chinensis were the dominant species. Plant species, the number of individuals, Ecological Dominance (Do), Shannon–Wiener index (H′), Simpson diversity index (Dsi) and Pielou evenness index (Epi) were affected by Cd and Cu contents of the soil and sediment. Therefore, the results indicate that Cu and Cd contents and ecological risk in the process of long-term vegetation restoration of small catchment in lead–zinc mine waste area should pay more attention. [ABSTRACT FROM AUTHOR]

Samples of groundwater and agriculture soil were collected from the surroundings of Kanpur Village situated near Zawar Mines, Udaipur to check Pollution Load Index of heavy metals. Kanpur Village is situated at a distance of 1.35km from the Tailing Dam at Zawar Mines. Four samples each of groundwater and agriculture soil were collected from around the village and agriculture fields soil and investigated for Pollution Load Index (PLI) for two seasons. In pre monsoon the PLI in water, ranged between 0.119-0.420 while in post monsoon it ranged from 0.169-0.751. In agriculture soil max. PLI in pre monsoon was 16.09 and min. was 10.80, and in post monsoon max. was 17.78 and min. 15.0. The aim of the present study is to estimate the impact of heavy metal pollution was in the form of the Concentration Factor (CF), Pollution Load Index (PLI) and Translocation Factor in water and soil samples obtained from surrounding of Kanpur village which is situated downstream of the Tailing Dam of Zawar Mines.

In this study, concentrations of Cr, Mn, Pb, Cu, Zn, As, Cd, Sb, and Fe were determined in soils of a Pb-Zn mine watershed in northern Guangxi, China, for ecological risk assessment and source analysis. The atomic fluorescence spectrometry and ICP-OES were used to determine concentrations of heavy metals (HMs), and the total amount of Mn, Cu, Zn, As, Cd, and Pb exceeded the limit. Among them, the weak acid extractable fraction (F1) state masses of Pb, Mn, and Zn accounted for a higher ecological risk. The study area was divided into three distinct areas: highest concentrations of HMs were distributed in front of the Sidi River mountain (1# and 2#) and at the subterranean river entrance (5# and 6#), followed by the area along the river and the irrigated area of the river (3# and 4#), and the central highlands and southwestern parts had low concentrations (7# and 8#). The ecological risk assessment results indicate Cd is of extremely high ecological risk, Pb and Mn are of medium minor ecological risk, Zn is of minor ecological risk, and the rest have almost no impact on the eco-environment. The source apportionment results showed that Cu, Zn, Cd, Sb, and Pb were mainly controlled by anthropogenic activities, such as mining; Cr, Fe, and As were mainly influenced by natural processes, such as soil-forming parent rocks; and Mn is jointly controlled by mining and soil-forming parent rocks. This study can provide scientific guidance and technical support for soil risk control or remediation in mining areas.

[Objective] The present paper aimed to reveal the effects of soil heavy metal pollution on the safety of diversified utilization of mulberry and the possible health risks caused by ingestion of mulberry products in abandoned lead-zinc mining area [Method]Taking the mulberry garden which had been ploughed for 14 years in the abandoned small lead-zinc mining area as the research object, the pollution status of heavy metals in mulberry products was analyzed by single factor pollution index and Nemero comprehensive pollution index. The target hazard coefficient was used to evaluate the effect of heavy metals in mulberry products on possible human health. [Result] (i) Under different limit standards, the single factor pollution index of cadmium and lead in mulberry trees planted in the study area was less than 1. 00 as the utilization mode of mulberry leaf and mulberry leaf tea, except for severe pollution [Pi(lead) = 5. 29] of fresh leaf mulberry leaf, which belonged to the clean level. (ii) The comprehensive pollution index of cadmium and lead was severe pollution (P = 4. 33). As the utilization mode of traditional Chinese medicine mulberry leaf and mulberry leaf tea, the single factor pollution index was less than 1. 00, which be longed to the clean level. (iii) The comprehensive pollution index of branch bark, branch stem and root bark as products developed by traditional Chinese medicine was 0. 09 - 0. 36, which all belonged to the clean level. (iv) Although the hazard coefficients of single cadmium target of mulberry leaves, mulberry branches and mulberry roots were all less than 1. 00, the hazard coefficients of single lead target and lead-cadmium com- pound heavy metal pollution target were more than 1. 00. Mulberry leaves polluted by lead and cadmium combined with heavy metals for a long time would have a negative impact on human health, and the health risk of children was higher than that of adults, but there was no chronic toxic effect [Conclusion] In the study area, the lead of mulberry planted in lead-zinc mining area can not be used in the development of mulberry leaf vegetables, but can be used in the product development of traditional Chinese medicine and mulbeny leaf tea [ABSTRACT FROM AUTHOR]

A total of 28,095 surface soil samples were collected in areas with high natural background levels; the potential ecological risk is generally low, and the high-risk area is small and mainly affected by lead–zinc mines. The contribution to the potential ecological risk factor (RI) is as follows: Hg > Cd > As > Pb > Cu > Ni > Cr > Zn, with noncarcinogenic chronic risks of Cr > As > Cd > Pb > Ni > Cu > Hg > Zn; furthermore, dermal contact is the main pathway of exposure causing health risks. The total carcinogenic risks caused by heavy metals were as follows: Cr > Cd > As > Pb; and the risks posed by Cr, Cd, and As were higher than the threshold value (1.0 × 10−4); people face a higher threat to heavy metals in soils in Zhenxiong, Ludian, Huize, Weixin, and Zhaoyang. The evaluation result of the EPA PMF model shows that the soil heavy metals are mainly composed of five sources, of which basalt, Permian, and Triassic carbonate rock parent material constitute the natural background source, while the mining activities of lead–zinc mines and the emissions of coal burning by residents constitute the anthropogenic source. The contribution was ranked in order of lead–zinc mining (26.7%) > Triassic carbonate (23.7%) > basalt (20.9%) > coal burning and automobile emissions (16.1%) > Permian carbonate (12.6%).

The heavy metals (HMs) usually have high natural background levels in lead-zinc mines. Strengthening the ecological risk assessment and accurate identification sources of HMs is an important component of land resource utilization and food security. A total of 795 soil samples (with a depth of 0~20 cm) were collected in Hezhang County, an area of typical high background levels of HMs with more than 18 large lead-zinc deposits. In this study, inductively coupled plasma emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), atomic fluorescence spectrometry (AFS), and the potentiometric method (POT) were used to test the total concentration of HMs and pH values. The geographic information system was used to model the concentration distribution of HMs, and the ecological risk was assessed according to the source analysis results. The results suggest that: (1) the mean concentration of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were 24.55, 2.25, 176.4, 89.6, 0.19, 64.2, 102, and 257 mg·kg−1, respectively, which exceeded the average background value of soils in Guizhou Province by 1.23, 3.41, 1.84, 2.80, 1.73, 1.64, 2.90, and 2.58 times, respectively, and the average concentrations of Cd, Cr, Cu, Ni, Pb and Zn exceed the screening values specified in soil contamination risk in agricultural land; (2) the results of enrichment factor (EF) showed that 29.73% of Cd are moderately polluted, and other HMs were slightly polluted in a small area or near the baseline value (EF ≈ 1); and (3) PMF analysis showed that there are five main sources, pyrite, lead-zinc ore, basalt, carbonate rock, and agricultural production, with the risk contribution ratios of 5.25%, 27.37%, 28.94%, 17.91%, and 20.53%, respectively.

Abstract Background Cd and Pb were the main pollution elements in Pb–Zn mining areas. Several studies have focused on heavy metal pollution and risk assessment in the Huize Pb–Zn mining area. In the present study, the soil aggregate composition, chemical properties, contents and chemical fractions of Cd and Pb were analysed in soils at depths of 0–60 cm in the Huize Pb–Zn mining area. Agricultural soils were sampled at depths of 0–20, 20–40 and 40–60 cm surrounding the Pb–Zn mine. The particle size fractions were determined by the aggregate composition of macro-aggregates (0.25–2 mm), micro-aggregates (0.053–0.25 mm), silt (0.002–0.053 mm) and colloid ( 33). Furthermore, there were close correlations between the Cd and Pb fractions and the pH and the phosphorus content and between the exchangeable Pb content and the content of organic matter, cation exchange capacity, and free iron oxide in soil aggregates. Conclusion Cd and Pb existed mainly in the micro-aggregate and colloid and that their chemical fractions were closely related to the chemical properties in soil aggregates of the polluted farmland.

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The root-associated microbiome assembly substantially promotes (hyper)accumulator plant growth and metal accumulation and is influenced by multiple factors, especially host species and environmental stress. Athyrium wardii (Hook.) is a phytostabilizer that grows in lead (Pb)-zinc (Zn) mine tailings and shows high root Pb accumulation. However, there remains little information on the assembly of the root-associated microbiome of A. wardii and its role in phytostabilization. A field study investigated the structural and functional variation in the root-associated bacterial microbiome of Athyrium wardii (Hook.) exposed to different levels of contamination in Pb-Zn mine tailings. The root compartment dominated the variation in the root-associated bacterial microbiome but the levels of contaminants showed less impact. Bacterial co-occurrence was enhanced in the rhizosphere soil and rhizoplane but tended to be much simpler in the endosphere in terms of network complexity and connectivity. This indicates that the microbial community assembly of A. wardii was non-random and shaped by root selective effects. Proteobacteria, Chloroflexi, Actinobacteria, Cyanobacteria, and Acidobacteriota were generally the dominant bacterial phyla. The genera Crossiella and Bradyrhizobium were enriched in the rhizosphere and cyanobacterial genera were enriched in the endosphere, demonstrating substantial advantages to plant survival and adaptation in the harsh mine environment. Functional categories involved in amino acid and carbohydrate metabolism were abundant in the rhizosphere soil, thus contributing to metal solubility and bioavailability in the rhizosphere. Membrane transporters, especially ATP-binding cassette transporters, were enriched in the endosphere, indicating a potential role in metal tolerance and transportation in A. wardii. The study shows substantial variation in the structure and function of microbiomes colonizing different compartments, with the rhizosphere and endophytic microbiota potentially involved in plant metal tolerance and accumulation during phytostabilization. [Display omitted] • Root selective effects led to a decrease in microbial diversity in the endosphere. • Rhizosphere and rhizoplane networks were enhanced but the endosphere network was simpler. • Crossiella and Bradyrhizobium were enriched in the rhizosphere and phylum Cyanobacteria enriched in the endosphere. • Predicted functional categories of microbiome differed across root compartments. [ABSTRACT FROM AUTHOR]

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The exposure of heavy metals (lead (Pb), cadmium (Cd), copper (Cu), nickel (Ni), and metalloid arsenicals) and their effects on workers' health from a lead-zinc mine (145 workers) and a steel smelting plant (162 workers) was investigated. Information on subject characteristics was obtained through a questionnaire. We determined the urinary levels of Pb, Cd, Cu, Ni, and arsenicals (including inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA), as were 8-hydroxydeoxyguanosine (8-OHdG) and cystatin C. Lead-zinc mine foundry workers had significantly higher concentrations of urinary Pb, Cd, Cu, Ni, iAs, and MMA than did steel smelting plant workers. Individuals who had consumed seafood in the previous 3 days had higher concentrations of urinary Ni than did individuals who had not consumed seafood. The urinary Cd concentrations in the two groups of factory workers may have been affected by daily smoking. There was no significant difference in urinary 8-OHdG between workers from the lead-zinc mine foundry and the steel smelting plant. Urinary Pb and Cd had significant positive linear dose-dependent effects on 8-OHdG. Urinary cystatin C, a sensitive biological indicator reflecting early renal damage, was found at higher levels in lead-zinc mine workers than in steel smelting plant workers. Binary logistic regression analysis showed that age and urinary Cd were significantly associated with urinary cystatin C. These results indicated that workers from lead-zinc mines may be exposed to higher levels of heavy metals which could lead to greater risk of kidney damage. [ABSTRACT FROM AUTHOR]

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[Objectives] The research was conducted to study characteristics of bioavailable levels pollution of heavy metals in the surface soil of the lead-zinc mine in Changhua. [Methods] A total of 56 surface samples were collected from the 3 study zones (peripheral zone, reclamation zone and tailing zone) located at the lead-zine mine in Changhua. Based on total and bioavailable heavy metals (Pb, Zn, Cu and Cd) in soils, the correlation of total content with bioavailable content was analyzed, and their pollution characteristics were assessed by methods of single factor pollution index, Nemerow pollution index, geological accumulation index and potential ecological risk index. [Results] (i) The surface soils were polluted by Pb, Zn, Cu, Cd in different degrees, and the overall trend of the contents of the 4 heavy metals was in order of Cd > Pb > Zn > Cu. The average excess multiple of heavy metals of total and bioavailable content in soils were in the order of peripheral zone > tailing zone > reclaimed zone, and their pollution degrees were tailing zone > peripheral zone > reclaimed zone, (ii) In general, the total and bioavailable contents of Pb, Zn, Cu, Cd showed a significant correlation, but were not correlated in each study zone. (iii) Pollution degrees of the study zones were in the order of tailing zone > peripheral zone > reclamation zone. The pollutions of heavy metals Pb and Cd were more serious, especially Cd reached high levels of pollution degree, and the pollution degrees of Zn, Cu were lighter. Contributors of ecological risk were mainly Cd, Pb and Cu, and the contribution of Cd achieved more than 90 %, making it the main source of pollution. [Conclusions] The results not only revealed the pollution status of heavy metals in the surface soil of the abandoned coal mine, but also could provide scientific guidance for reasonable utilization and ecological recovery of the land. [ABSTRACT FROM AUTHOR]

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For studying the interspecific differences and accumulation features of cadmium(Cd) and lead(Pb) about different alfalfa(Medicago Sativa L) varieties, greenhouse experiments were carried out in a lead-zinc mine of Yunnan and the indexes including plant height, biomass, content and accumulation of Cd and Pb, enrichment coefficient and transfer coefficient were measured. The results showed that from the enrichment coefficient, the variety having the strongest Cd accumulation capacity was "Youke", its Cd enrichment coefficient, Cd content of shoot, Cd accumulation of shoot were respectively 0.054, 0.22 mg·kg-1 and 40.58 μg·m-2 and were higher respectively by 145%, 100% and 145% than that of the weakest varieties "WL525HQ" in anthesis(120 day). The svariety having the strongest Pb accumulation capacity was "Guochan", its Pb enrichment coefficient, Pb content of shoot, Pb accumulation of shoot were respctively 0.035, 2.67 mg·kg-1 and 282.2 μg·m-2 and were higher respectively by 52%, 53% and 10% than that of the weakest varieties "WL525HQ" in anthesis(120 day). From transfer coefficient, most of cultivars used in experiments had a certain capacity for transfering Cd and Pb from root to shoot. The variety having the strongest Cd transfer capacity was "Sandeli", its Cd transfer coefficient was 1.545 and was higher by 72% than that of the weakest varieties "Guochan" in anthesis(120 day). The variety having the strongest Pb transfer capacity was "Guochan", its Pb transfer coefficient was 2.048 and was higher by 71% than that of the weakest varieties "Duoye" in anthesis(120 day). In conclusions the inerspecific differences of Cd and Pb accumulative characteristics were existed among alfalfa cultivars used in the experiments, Based on metal content in shoot "Youke" and "Guochan" could be considered as Cd and Pb high accumulation cultivar respectively, whereas "Sijiwang" and "WL525HQ" could be considered as Cd and Pb low accumulation cultivar respectively. [ABSTRACT FROM AUTHOR]

[Objective] T1 k: research was conducted to study characteristics of bioavailahle concentrations pollution of heavy metal in tin; surface soil of Changhua lead and zinc mine. [Method] 56 surface samples in 3 study zones( peripheral zone, reclamation zone and tailing zone) were collected from wasteland soils located at Changhua lead-zinc mine, based on total and available heavy metal( Pb, Zn, Cu and Cd )in soils, their correlation of total content with available content was analyzed, and their pollution characteristics by methods of single factor pollution index, Nemerow pollution index, geological accumulation index and potential ecological risk index were assessed. [K esu It] ( i) The surface soils were polluted by Pb, Zn, Cu, Cd in different degrees, the four heavy metal of overall trend was in order of Cd > Pb >Zri >Cu, average excess multiple of heavy metal of total and available content were peripheral zone > tailing zone > reclamation zone in soils, and their pollution degrees were peripheral zone > tailing zone > reclamation zone from the study zone; ( ii) In general Pb, Zn, Cu, Cd of total content and available showed a significant linear correlation, but total and available contents were not a correlation every study zone; (iii)Pollution degrees of study zone were peripheral zone > tailing zone > reclamation zone, tin; pollutions of heavy metals Pb and Cd were more serious, especially tin; Cd reached high levels of pollution degree, and tin; pollution degrees of Zn, Cu were lighter. Contributors of ecological risk were mainly for Cd, Pb and Cu, especially, tin; contribution of Cd achieved more than 90 %, which was a main source of pollution. [Conclusion] The results not only reveal tin; pollution status of heavy metal in tin; surface soil of tin; abandoned coal mine, but also could provide; scientific guidance for reasonable; utilization ariel ecological recovery. [ABSTRACT FROM AUTHOR]

Pollution by heavy metals presents an environmental concern, and their toxicity threats soil, water, animals and human health. Phytoremediation can be used as a solution to remediate contaminated soils. The aim of this study was to identify native plants collected from tailings: material of Pb-Zn mine sites of Fedj Lahdoum and Jebel Ressas (two abandoned mines located, respectively, in the northwest of Tunisia and in the south of Tunis City). The tolerance of plant to heavy metals (lead, zinc and cadmium) is evaluated. Soil samples were collected and analyzed for Pb, Zn and Cd concentration. The total soil Pb, Zn and Cd are, respectively, reached 6132 mg kg, 11,052 mg kg and it doesn't exceed 479 mg kg for Cd. The highest content of Zn in plants was detected in shoots of Rumex bucephalophorus (1048 mg kg), and the highest Pb concentration was detected in roots of Chrysopogon zizanioides (381 mg kg), while for Cd Silene colorata it accumulated the highest content in roots (51 mg kg). From all plants, only 12 have a translocation factor for Pb which is higher than one. Among all plants, only 17 have a translocation factor that is higher than one for Zn, while for Cd only 13 plants indicate TF > 1. As for the biological absorption coefficient, all samples indicate a rate which is lower than one. These plants can be primarily hyper accumulators and useful in remediation of lead- and zinc-contaminated soils after further biochemistry researches in mechanism of accumulation and translocation of heavy metals in plants. [ABSTRACT FROM AUTHOR]

The contents of chemical elements (Cd, Cr, Cu, Pb and Zn) in 11 kinds of crop/vegetables and soils around the Huodehong lead-zinc mining area in Yunnan, Southwest China were determined by using inductive coupled plasma emission spectrometry (ICP-MS). Results showed that element contents in soils decreased in the order of Zn > Pb > Cr > Cu > Cd. The high geo-accumulation indexes ( I geo ) showed that cultivated soils near mine were practically polluted by Cd, Pb and Zn. The contents of Cd, Cr and Pb in crop/vegetables samples were significantly higher than the maximum permissible standard set by China. The potential health risk assessments among local residents were evaluated by the hazard index ( HI ), the total carcinogenic risk ( TCR ), the target hazard quotient ( THQ ) and carcinogenic risk ( CR ), respectively. The results showed that diet was the dominant exposure pathway. The results of HI for adult and child were 6.21 and 6.08, respectively. TCR values of Cr and Cd were more than 10 −4 . The THQ decreased in the following order: Cd > Pb > Cu > Zn > Cr. Among all kinds of crop/vegetables, leafy-vegetables were the major source of Cd and Pb exposure, root-vegetable were the important factors for Cu and Zn exposure, but tuber-vegetable were the factors for Cr exposure. The contents of Cd and Pb in human scalp hairs near Huodehong mine were higher than that in S 20km area. Females possessed a higher risk for Cd, Cr, Cu and Pb exposure than males in study area. Significant differences between ages were found for Cd, Cu and Pb ( p < 0.01). This study provided a powerful basis for the coordination of local environmental protection and economic sustainable development and assessing chemical elements risk to human health. [ABSTRACT FROM AUTHOR]

Purpose: This study investigated the extent of metal accumulation by plants colonizing a mining area in Yazd Province in Central Iran. It also investigated the suitability of these plants for phytoextraction and phytostabilization as two potential phytoremediation strategies. Materials and methods: Plants with a high bioconcentration factor (BCF) and low translocation factor (TF) have the potential for phytostabilization, whereas plants with both BCFs and TFs >1 may be appropriate for phytoextraction. In this study, both shoots and roots of 40 plant species and associated soil samples were collected and analyzed for total concentrations of trace elements (Pb, Zn, and Ag). BCFs and TFs were calculated for each element. Results and discussion: Nonnea persica, Achillea wilhelmsii, Erodium cicutarium, and Mentha longifolia were found to be the most suitable species for phytostabilization of Pb and Zn. Colchicum schimperi, Londesia eriantha, Lallemantia royleana, Bromus tectorum, Hordeum glaucum, and Thuspeinantha persica are the most promising species for element phytoextraction in sites slightly enriched by Ag. Ferula assa-foetida is the most suitable species for phytostabilization of the three studied metals. C. schimperi, L. eriantha, L. royleana, B. tectorum, M. longifolia, and T. persica accumulated Ag, albeit at low level. Conclusions: Our preliminary study shows that some native plant species growing on this contaminated site may have potential for phytoremediation. [ABSTRACT FROM AUTHOR]

An accumulation of heavy metals in soil poses a risk to the ecological environment and human health. In this study, the concentrations of heavy metals in soil and crops were examined in a lead-zinc mining area in Guizhou Province, China. The distribution and sources of heavy metals were analyzed using GIS spatial mapping. The potential ecological risks of heavy metals were assessed using the potential ecological risk index (RI), and the human health risk assessment method recommended by the United States Environmental Protection Agency (USEPA) was used to quantify the health risk of residents exposed to heavy metals in the soil around lead-zinc mines. According to the results, the average of concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in the soil were 58, 7.9, 175, 64, 0.461, 65, 1539, and 2513 mg·kg -1 , respectively, which were significantly higher than the background values in Guizhou Province. It was found that the As, Cd, Cu, Hg, Pb, and Zn concentrations were extremely irregular in the soil and that the concentrations decreased significantly with the distance to the smelters, which were greatly disturbed by human activities. Comprehensive evaluation of soil heavy metals using the potential ecological risk index revealed that the risks of soil heavy metals were pole-strength and strong levels, and Cd constituted the primary ecological risk factor. A total of 22% and 10% of the corn samples contained Pb and As above the heavy metal pollution thresholds in the national food safety standards. According to human health risk assessments, heavy metals in the soil present potential non-carcinogenic risks to adults or children, and pose a potential carcinogenic risk to children. Soil pH was an important controlling factor affecting the bioavailability, migration, and accumulation of Cd in soil-crop systems. This study provides data and theoretical support for the prevention and control of soil pollution in lead-zine mining areas.