Influence Of Mining Activities Research Articles

Machine learning-based prediction of cadmium pollution in topsoil and identification of critical driving factors in a mining area.

Mining activities have resulted in a substantial accumulation of cadmium (Cd) in agricultural soils, particularly in southern China. Long-term Cd exposure can cause plant growth inhibition and various diseases. Rapid identification of the extent of soil Cd pollution and its driving factors are essential for soil management and risk assessment. However, traditional geostatistical methods are difficult to simulate the complex nonlinear relationships between soil Cd and potential features. In this study, sequential extraction and hotspot analyses indicated that Cd accumulation increased significantly near mining sites and exhibited high mobility. The concentration of Cd was estimated using three machine learning models based on 3169 topsoil samples, seven quantitative variables (soil pH, Fe, Ca, Mn, TOC, Al/Si and ba value) and three quantitative variables (soil parent rock, terrain and soil type). The random forest model achieved marginally better performance than the other models, with an R2 of 0.78. Importance analysis revealed that soil pH and Ca and Mn contents were the most significant factors affecting Cd accumulation and migration. Conversely, due to the essence of controlling Cd migration being soil property, soil type, terrain, and soil parent materials had little impact on the spatial distribution of soil Cd under the influence of mining activities. Our results provide a better understanding of the geochemical behavior of soil Cd in mining areas, which could be helpful for environmental management departments in controlling the diffusion of Cd pollution and capturing key targets for soil remediation.

Influence of mining activities on hydrological processes in the mining district, Loess Plateau: insights from spatio-temporal variations of δD and δ18O

Under the influence of mining activities, investigating hydrological processes is an important cornerstone of water resources and eco-environment protection. In this study, the spatio-temporal variations of stable isotopic compositions (δD and δ18O) of river water and groundwater in five periods of a hydrological year were analyzed to identify the origin and hydraulic connection of water bodies in the mining district under mining disturbance. The δD and δ18O indicate that the water bodies in the study area are mainly recharged by local precipitation and undergo evaporation. There is a close hydraulic connection between river water, mine water, and groundwater, and the deep confined water is affected by the river water and phreatic water due to the developing water-conducting fractures. The δ18O of phreatic water in each period is depleted in the southwest and enriched in the northeast of the study area. The δ18O of confined water has an obvious spatial variation in the wet season due to the combined effects of opencast working and underground mining, whereas uniform spatial variation is observed in the dry season. Compared with the dry season, mining disturbances have a greater impact on river water and groundwater in the wet season. The difference in spatial variation of δ18O between phreatic and confined water may be attributed to the easier recovery of phreatic water than confined water after mining disturbance. This finding provides important information about the hydrological characteristics of the Pingshuo mining district.

Characteristics of Perimeter Rock Damage in a Bottom-Pumping Roadway under the Influence of Mining Activities and Rational Location Studies: A Case Study

With the aim of determining the damage characteristics and a reasonable positional arrangement of the surrounding rock in a bottom-pumping roadway influenced by mining in a high-gas mine, the boundary equation for the plastic zone of the surrounding rock in a circular roadway under an unequal compressive stress field was adopted to analyze the relationship between the distribution characteristics of the plastic zone of the bottom-pumping roadway and the stability of the rock surrounding the bottom-pumping roadway under different bidirectional stress ratios. This was carried out in the bottom-pumping roadway of the working face of Licun coal mine 3301 as the engineering background, where the nature of the coal seams mined is bituminous coal, and the absolute gas outflow is 0.5 m3/min−1. A numerical simulation was used to analyze the distribution characteristics of the surrounding rock stress and the bidirectional stress ratio, as well as the deformation and damage characteristics of the surrounding rock at different positions in the bottom-pumping roadway. A numerical simulation was applied to analyze the distribution characteristics of the surrounding rock stress and the two-way stress ratio, as well as the deformation and damage characteristics of the rock surrounding the bottom-pumping roadway when the bottom-pumping roadway was arranged in different locations. The results show that, with an increase in the bidirectional stress ratio, the plastic zone of the perimeter rock in the bottom-pumping roadway shows nonuniform “butterfly” distribution characteristics, which seriously affects the stability of the rock on the perimeter of the roadway; the stress on the bottom plate of the working face after excavation can be divided into four areas according to the size of the bidirectional stress ratio and the stress loading and unloading states. In addition, the size of the perimeter rock deformation can be sorted into four areas according to the damage range of the perimeter of the rock plastic zone in the bottom-pumping roadway. The size of the deformation in the surrounding rock can be sorted as follows: unpressurized high-stress ratio > unpressurized stress ratio stable area > pressurized low-stress ratio area > original rock stress ratio area. Accordingly, we found that the reasonable location of the bottom-pumping roadway is arranged at the 15 m position outside the hollow area below the coal pillar, along the limestone upper medium-grained sandstone layer along the bottom. The study’s results were applied to the field. The industrial experiments on the site show that the deformation of the surrounding rock is reasonable when the bottom-pumping roadway is dug along the limestone roof and arranged 15 m outside the fault of the mining hollow area below the coal pillar.

Macroinvertebrate diversity and assessment of water quality in the area under the influence of mining activities in the Yaouré basin (Kossou, central of Côte d'Ivoire)

Macroinvertebrate diversity and assessment of water quality in the area under the influence of mining activities in the Yaouré basin (Kossou, central of Côte d'Ivoire)

Soil acidification in a tailing area of ionic rare earth in Southeast China

Ionic rare earth ores are now commonly mined using the ammonium sulfate in situ leaching method, causing soil acidification in tailings. To evaluate the degree of soil acidification in tailings and the influence of mining activities on acidification, we selected an ionic rare earth tailing and a nearby unmined area in Southeast China. This tailing had been closed for 12 years. We sampled the soil from the surface to the bedrock in layers and determined soil properties related to soil acidification. The results showed that the average soil pH was 5.0 in the unmined area and 4.5 in the mined area (tailing area). Rare earth mining led to a decrease in soil pH of 0.47 units per 10 years, which was 2–5 times higher than that of other land uses. The shallow soil acidification in the mined area is not affected by mining. Deep soils were significantly acidified and the H+ concentration in the soil solution was approximately nine times that of the unmined area soil. Deep soil acidification is influenced very little by natural factors. The average soil ammonium‑nitrogen (NH4+-N) and nitrate‑nitrogen contents in the mined area were 58.34 mg kg−1 and 8.19 mg kg−1, respectively, 84 times and 21 times that of the unmined area. There were large amounts of NH4+, NO3−, and H+ in the soil of the mined area, indicating that soil acidification is closely related to exogenous NH4+-N input and nitrogen transformation. Nitrification is the most important driver of soil acidification in mining areas. Continued nitrification of excess NH4+-N will continue to produce H+ and migrate with water, which will cause long-term harm to the soil and surrounding environment in the mining area. Therefore, it is necessary to remove the enriched NH4+-N in tailings soil to avoid further soil acidification.

Hydrochemical evolution of groundwater in overburden aquifers under the influence of mining activity: combining hydrochemistry and groundwater dynamics analysis

Hydrochemical evolution of groundwater in overburden aquifers under the influence of mining activity: combining hydrochemistry and groundwater dynamics analysis

Study on the Influence of Mining Activities on the Quality of Deep Karst Groundwater Based on Multivariate Statistical Analysis and Hydrochemical Analysis.

Long-term mining activities have changed the hydrogeochemical evolution process of groundwater and threatened the safe use of groundwater. By using the methods of hydrochemistry and multivariate statistical analysis, this study determined the hydrogeochemical evolution mechanism affecting the quality of karst groundwater by analyzing the conventional hydrochemistry data of the karst groundwater of the Carboniferous Taiyuan Formation in Hengyuan Coal Mine in the recent 12 years. The results show that, under the disturbance of mining, the quality of karst groundwater in Taiyuan Formation is poor, mainly because the contents of Na++K+ and SO42- are too high to allow usage as drinking water. The reason for the high content of SO42- in karst groundwater lies in the dissolution of gypsum and the oxidation of pyrite, and the high content of Na++K+ lies in the cation exchange. Influenced by the stratum grouting, the circulation of karst groundwater is improved, the cation exchange is weakened, and the desulfurization is enhanced. In the future, it is predicted that the hydrochemical type of karst groundwater in Taiyuan Formation in the study area will evolve from SO4-Ca·Mg type to HCO3-Ca Mg type.

Effect of parent material and atmospheric deposition on the potential pollution of urban soils close to mining areas

The aim of this study is to analyse the concentration and determine the sources of potentially toxic elements (PTEs) in urban soils under the influence of mining activities. To this end, topsoil samples were collected in the public parks and green areas in Minas de Riotinto (a town next to one of the largest open pit mines in the world) and Aracena (a nearby town outside the area of influence of the mine). After determining the concentrations of elements of interest Cr, Co, Ni, Cu, Zn, As, and Pb— the values were compared in terms of the soil location and origin (in-situ or ex-situ), and with the background and regulatory levels for the region. The elemental concentrations in the fine fraction of the soils (particles <50 μm) were also measured. The concentrations of some PTEs (Cu, As and Pb), also found in the dust from nearby mines, were higher in the in-situ soils of Minas de Riotinto than in those of Aracena. The concentrations of PTEs in ex-situ soils of both towns were much lower than in in-situ soils, and similar between the two locations, revealing the influence of the parent material as a primary source of PTEs. However, the concentrations of As and Cu in the ex-situ soils of Minas de Riotinto were significantly higher than in those of Aracena, while a significant increase of these elements in the fine fraction was seen for both in-situ and ex-situ soils. These two elements are directly related to mining activity, implying that atmospheric deposition of dust from the mines contributes to the greater concentration of PTEs in the soils of Minas de Riotinto. Because these sources lead to soils with potentially dangerous concentrations of pollutants, they should be further studied in relation to their long-term influence on human health.

Twenty years of coal mining-induced subsidence in the Upper Silesia in Poland identified using InSAR

The paper presents the results of terrain subsidence monitoring in Poland’s Upper Silesian Coal Basin (USCB) mining area using Differential Interferometry Synthetic Aperture Radar (DInSAR) and Persistent Scatterer Interferometry (PSI). The study area accounts for almost three million inhabitants where mining which started in the 19th century, has produced severe damage to buildings and urban infrastructures in past years. The analysis aimed to combine eight different datasets, processed in two techniques, coming from various sensors and covering different periods. As a result, a map of areas that have been exposed to subsidence within 3045 square kilometers was obtained. The map covers a period of twenty years of intensive mining activities, i.e. 1992–2012. A total of 81 interferograms were used in the study. The interferograms allowed not only to determine subsidence troughs (basins) formed from 1992 to 2012 but also to observe subsidence development over time. The work also included five sets of PSI processing, covering different temporal and spatial ranges, which were used to determine zones of residual subsidence. Based on InSAR datasets, an area of 521 square kilometers under the influence of mining activities were determined. Within the subsiding zones, an area of 312.5 square kilometers of the rapid increase in subsidence was identified on the interferograms. The study of combined different InSAR datasets provided large-area and long-term information on the impact of mining activities in the Upper Silesia Coal Basin.

Spatiotemporal Differentiation Characteristics of Land Ecological Quality and Its Obstacle Factors in the Typical Compound Area of Mine Agriculture Urban

Mining activity combines industrialization, urbanization, and urban-rural integration in the compound area of mine agriculture urban. The land ecological environment has become a major hidden problem, restricting the sustainable development and ecological security of the region. It is imminent to understand the spatiotemporal differentiation characteristics of land ecological quality and its obstacle factors to scientifically carry out land ecological restoration. Here, the Macun coal area in Jiaozuo City, Central China, was selected for the case study, and an evaluation index system including four criteria layers of ecological foundation, structure, benefit, and stress was established. The multiperiod evaluation index data were acquired by utilizing remote sensing and geographic information system (GIS) technology. Based on the multi-objective comprehensive evaluation method, a comprehensive evaluation of land ecological quality was conducted, and the spatiotemporal differentiation characteristics of land ecological quality were explored. Moreover, an obstacle factor diagnosis model was constructed to confirm the spatiotemporal differentiation characteristics of obstacle factors affecting the change of the land ecological quality in the study zone. The results showed the following: (1) From 1980 to 2020, the land ecological quality index in the study zone showed a downward trend, and the proportion of the regional area with general and poor land ecological quality increased from 6.55% to 35.02%. (2) The areas with lower land ecological quality in each period of the study zone were mainly distributed in the mining areas with long mining history in the west and the areas with continuous urbanization and industrialization in the south. In contrast, the compound area of mine agriculture urban with short mining history in the east and southeast had higher land ecological quality. The aggregation of the land ecological quality index also showed similar spatial distribution characteristics. (3) The diagnosis results of obstacle factors showed that, due to the poor land ecological foundation and interference of mining activities, the land ecological quality of the mountain area in the north and west of the study area has been low. It is suggested that the land ecological quality of the area should be improved through measures such as terrain regulation, soil reconstruction, afforestation, and forest land conservation. Under the influence of mining activities and the continuous promotion of urbanization in the south of the study area, the regional ecological quality has been reduced. It is suggested that the regional land ecological quality should be improved by building ecological agriculture and ecological communities. The northeast of the study area is still in the mining area, and the ecological quality of the land tends to deteriorate. The ecological restoration in this area should be conducted by the combination of pre-mining planning, while-mining control, and post-mining restoration. The methodology of this study can provide reference for the identification and restoration of land ecological problems in the compound area of mine agriculture urban.

Quantitative estimation for the impact of mining activities on vegetation phenology and identifying its controlling factors from Sentinel-2 time series

Quantitative assessment of the negative environmental effects of mining is vital for the eco-environmental restoration and management of mining areas. However, it remains unclear about the spatial dimension of the influence on the environment that comes from mining. Here, we constructed a new method to quantify the vegetation impact of mining activity using Sentinel-2 time series and Pareto principle, and applied it to the Liaoning Nanfen iron mining area (LNMA), the Inner Mongolia Sanheming iron mining area (IMMA), and the Sichuan Hongge iron mining area (SCMA) in China. Based on the unequal relationship of 80% of the consequences determined by 20% of the causes, the influence of mining activities on vegetation was quantified by the maximum phenological difference, the decay rate, the asymptotic value of exponential trend and the distance from the mine. Results showed that the impact of mining activities on vegetation phenology decayed exponentially along with the increase of the distance to the mines. The influence distance of mining activities on vegetation were 1566.95 m, 1959.67 m, and 1809.61 m for LNMA, IMMA and SCMA, respectively. Compared to areas 5 km away from the mining activity, the start of the growing season for vegetation surrounding the mining activity was delayed by 1.1 ± 0.4 days, 6.1 ± 1.9 days, and 1.5 ± 0.7 days for LNMA, IMMA and SCMA, respectively, while the length of the growing season was successively shortened by 1.0 ± 0.6 days, 5.4 ± 2.5 days, and 5.1 ± 3.9 days, respectively. Our investigation found that the dust pollution, decreases in groundwater levels, and waterborne pollution were the main factors that directly caused phenological changes around the mining area, and the distance and degree of their impact on phenology were closely related to drought and topography. This finding could provide a reference for the environmental restoration and management of mining areas and help to add insights on the assessment for the long-term impacts of mining activities on vegetation.

Analysis of the Influence of Fault Fracture Zone on Mining Response Based on FDM-DEM Coupling

Fault slip will cause a change in mining stress at the longwall face, which will cause adverse effects. In this study, on the basis of Fast Lagrangian Analysis of Continua in 3 Dimensions (FLAC3D) and Particle Flow Code in 3 Dimensions (PFC3D), the sliding of the fault fracture zone and its impact on the longwall working face were analyzed. The rock mass of the fault fracture zone with a certain thickness was constructed using rigid random model particles. The coupling between the wall element of PFC3D and the zone element of the continuous medium in the software was used to realize the transmission of force and displacement, and the interaction between the fault fracture zone and the working face was studied. The influence of the slip of different fault zone positions on the fault and working face was also explored using the method of externally disturbing the fracture zone of the fault. The numerical results showed that as the distance between the fault and the working face continued to decrease, the peak stress concentration in front of the longwall face first increased, then decreased, and gradually shifted to the vicinity of the fault zone. The stress mutation and fault slip occurred within a certain distance of the longwall face from the fault. When fault slip activation begins, the stress near the fault zone showed a sudden change of varying degrees with the advancement of the longwall face. This sudden change was caused by the influence of mining activities from the activation distance of the rock in the fault fracture zone and the rolling extrusion of the rock mass in the fracture zone. When the fault zone closer to the working face was disturbed, the influence on the fault zone and longwall face was greater. When the fault zone near the coal seam was disturbed, the rock mass and working face near the fault zone brought different degrees of dynamic responses, which were mostly instantaneous and had high frequency and amplitude. The results of this research could help in the mining of longwall mining affected by fault zones and have a certain guiding role in coal mining before crossing faults.

Impact of human and environmental interactions on flooding incident in the Jeneberang River South Sulawesi

Human interaction with the environment due to negative impacts. This can be seen, among others, in the interaction of the community with the environment in the Jeneberang watershed area, South Sulawesi Province, which has an impact in the form of flood events. This paper aims to determine the extent of the impact of human and environmental interactions on flooding in the area. The study was carried out through several studies and studies on human interactions and the natural environment in the Jeneberang watershed, literature studies, reviewing and concluding various journals, as well as collecting data through analysis of maps and secondary data from relevant agencies and primary data from the community as the main actors. The results of the study indicate that human interaction with the environment in the Jeneberang watershed has an impact in the form of flooding because the Jeneberang watershed management activities have not been optimally integrated, which are indicated by: 1. Watershed characteristics are not taken into account in infrastructure development. 2. There is still limited understanding of land-use communities about the characteristics of rainfall and surface runoff, as well as their relation to landslides and sedimentation, 3. The influence of mining activities on river flow narrowing and dam silting is not taken into account, and 4. The occurrence of vegetation degradation in downstream. In order to optimize flood control efforts in the Jeneberang river, it is necessary to carry out integrated management of the Jeneberang watershed by integrating all activities in all sectors. Planning for flood control and environmental conservation in general needs to really consider physical factors in the form of climate, hydrology, geology, tectonics, in addition to vegetation, management, technology, and socio-economic and cultural factors. Communities need to be motivated to continue trying to increase their income and welfare, accompanied by efforts to increase understanding and awareness of the importance of maintaining and preserving the environment, through diversifying livelihoods and utilizing natural resources and land that always prioritizes conservation aspects.

Occurrence and distribution of emerging contaminants in mine-impacted lake water and potential use as co-tracers of anthropogenic activity in the subarctic region, Northwest Territories, Canada

The emerging contaminant (EC) perchlorate (ClO4−), a blasting agent widely used in mining and refining operations, has been used as a practical indicator of mining activities. Widespread occurrence of ECs, such as pharmaceutical compounds, artificial sweeteners, and perfluoroalkyl substances, and their use as co-tracers of wastewater associated with anthropogenic activities in the urban and Arctic environments have been previously investigated. However, limited studies have reported the occurrence of these ECs and the feasibility of their use as co-tracers of anthropogenic activities in pristine waterbodies (e.g., continuous permafrost region) that receive effluent from mine sites. In this study, water samples were collected from the surface of 10 lakes within the Coppermine and Lockhart Watersheds in the continuous permafrost region in the Northwest Territories, Canada during the open water seasons of 2016, 2017, and 2018. Concentrations of 16 ECs were determined to delineate the spatial and temporal distribution of these compounds in waterbodies receiving effluent from mine sites. Slightly elevated concentrations of ClO4− (100–700 ng L−1), caffeine (0.2–5.9 ng L−1), acesulfame-K (0.5–1.5 ng L−1), perfluorooctanoic acid (PFOA; 5–34 ng L−1), perfluorooctane sulfonic acid (PFOS; 11–40 ng L−1), chloride (1.5–2.3 mg L−1), and sulfate (1.0–3.6 mg L−1) were observed across the two investigated watersheds, especially downstream of the mining sites. The concurrence of elevated concentrations of these target ECs combined with other dissolved constituents (chloride and sulfate) may indicate the influence of mining activity on the receiving waterbodies and the potential use of these compounds as co-indicators of anthropogenic activity. Results from this study provide novel information on the distribution of 16 ECs in pristine waterbodies that receive effluents from mining sites in the Canadian subarctic in advance of more expansive human development and increased warming and melting of mine sites, including mine wastes.

Particularities of deformation processes solution with GIS application for mining landscape reclamation in East Slovakia

The influence of mining activity on the environment on the environment belongs to the most negative industrial influences. Mine subsidence on the surface can be a result of many deep underground mining activities. The present study offers the theory to the specific case of the deformation vectors solution in a case of disruption of the data homogeneity of the geodetic network structure in the monitoring station during periodical measurements in mine subsidence. The theory was developed for the mine subsidence at the abandoned magnesite mine of Košice-Bankov near the city of Košice in East Slovakia. The outputs from the deformation survey were implemented into geographical information system (GIS) applications to a process of gradual reclamation of whole mining landscape in the magnesite mine vicinity. After completion of the mining operations and liquidation of the mine company, it was necessary to determine the exact edges of the mine subsidence of Košice-Bankov with the zones of residual ground motion in order to implement a comprehensive reclamation of the devastated mining landscape. Requirement of knowledge about stability of the former mine subsidence was necessary for starting the reclamation work. Outputs from the present specific solutions of the deformation vectors confirmed the multi-year stability of the mine subsidence in the area of interest. Some numerical and graphical results from the deformation vectors survey in the abandoned magnesite mine of Košice-Bankov are presented. The obtained results were transformed into GIS for the needs of the municipality of Košice City to the implementation of the reclamation activities in the mining territory of Košice-Bankov.

Influence of Mining Activities on Arsenic Concentration in Rice in Asia: A Review

Crop and livestock farming on contaminated soil has been found to induce the accumulation of trace elements in edible parts of plants, with subsequent risk to human and animal health. Since rice crop is a major source of energy in worldwide diets and is consumed by more than 3 billion people, the soil–rice pathway is regarded as a prominent route of human exposure to potentially toxic elements. This study provides an overview of arsenic contamination in paddy rice from mining-impacted areas in several Asian countries that are primary rice consumers. From this review, it may be concluded that mining activities, along with the associated residual waste, significantly contribute to arsenic contamination of this food crop as rice samples from these regions were highly contaminated, with the highest total arsenic concentrations recorded being 3–4 times higher than the maximum levels proposed by the Codex Alimentarius Commission. While the contamination in China, Korea, Indonesia, and Thailand appeared to be slightly affected by mining activities, the elevated levels of arsenic in rice from mining areas in India, Bangladesh, and Vietnam could be derived from arsenic-contaminated groundwater.

Geochemical distribution, statistical and health risk assessment of toxic elements in groundwater from a typical mining district in Nigeria

Globally, the influence of mining activities on the quality of drinking waters have been reported by several researchers. Long-term exposure to potentially toxic elements (PTEs) (e.g. As, Cd, Co, Cu, Fe, Mn, Ni, Pb, Se and Zn) can cause serious health hazards to consumers of polluted water. In the current study, twenty groundwater samples from Ameka mine area were analyzed for PTEs pollution and the associated human health risks. The concentrations of As, Cd, Ni, Pb Co, and Se were found to be above their standard limits in majority of the samples. Index methods such as heavy metal evaluation index, heavy metal pollution index and contamination degree confirmed that majority of the samples are loaded with PTEs. Similarly, synthetic pollution index further revealed that all the samples are extremely polluted and thus very unsuitable for human consumption. The health risk assessment model proposed by US-EPA was applied in assessing the associated health risks of PTEs in the groundwater resources. Non-carcinogenic health risk assessment predicted that 100% of the samples have hazard index values > 4, indicating an extremely high chronic health risk for adults and children. Similarly, carcinogenic risk assessment showed that all the samples pose high cancer risk to both populations due to As, Ni and Cd pollution. However, all the samples pose low cancer risk due to Pb enrichment. Multivariate statistical analyses (such as Pearson’s correlation matrix and principal component extractions) indicated that mining activities and rock-water interactions (weathering) are the responsible sources for the elemental pollution of the groundwater system. Before consumption, adequate treatment is recommended for the polluted waters.

Toxicity of representative mixture of five rare earth elements in juvenile rainbow trout (Oncorhynchus mykiss) juveniles

Rare earth elements (REEs) are contaminants of increasing interest due to intense mining activities for commercial purposes and ultimately released in the environment. We exposed juvenile rainbow trout (Oncorhynchus mykiss) to a representative mixture of the five most abundant REEs for 96 h at concentrations similar found in lakes contaminated by mining activities at 0.1, 1, 10, and 100X whereas the 1x mixture contained cerium (Ce, 280 μg/L), lanthanum (La, 140 μg/L), neodymium (Nd, 120 μg/L), praseodymium (Pr, 28 μg/L), and samarium (Sm, 23 μg/L). We investigated the expression of 14 genes involved in oxidative stress, DNA repair, tissue growth/proliferation, protein chaperoning, xenobiotic biotransformation, and ammonia metabolism in the liver. In addition, DNA damage, oxidative stress (lipid peroxidation or LPO), inflammation (cyclooxygenase or COX activity), detoxification mechanisms (glutathione-S-transferase activity or GST), and labile zinc were determined in gills. The data revealed that genes involved in oxidative stress-catalase (cat), heat shock proteins 70 (hsp70), and glutamate dehydrogenase (glud) were upregulated while glutathione S-transferase (gst) and metallothionein (mt) gene expressions were downregulated. The mixture was genotoxic and increased labile Zn in gills of exposed trout. These changes occurred at concentrations 600 times lower than the LC50 for this mixture indicating effects below the 1X concentration. Based on principal component analysis and concentration-dependent reponses, the following sublethal effects were considered the most important/significant: DNA strand breaks (genotoxicity), labile Zn, cat, gst, hsp70, sparc, mt, and glud. These effects of fish juveniles are likely to occur in environments under the influence of mining activities.

Nickel spreading assessment in New Caledonia by lichen biomonitoring coupled to air mass history.

Lichen biomonitoring and air mass trajectories were used to study the influence of mining activities in the atmospheric dispersion of metallic elements to assess the exposure of the population to dust emitted by mining activities. A map of forward trajectory densities from open mine surfaces throughout New Caledonia was computed and allowed to identify three preferred wind directions (trade wind, bent trade winds and oceanic winds) that could arise in mining particles dispersion all over New Caledonia. Areas where an air quality monitoring would be advisable to evaluate the exposure of the population to the Nickel dusts have been identified. Lichens collected around the industrial mining site KNS and in North Provence of New Caledonia were analysed for their Ni, Co, Cr, Zn and Ti contents. Backward trajectories were simulated from the lichen sampling point using FLEXTRA fed with ECMWF meteorological data, and densities of trajectories having overflown a mine were calculated. Ratio metal/Ti was then plotted as a function of air mass trajectory densities having overflown open pits. A positive correlation between trajectory densities and titanium-normalized metal in lichen for Ni, Co, Cr was highlighted, indicating that mining is a source of dispersion of these metals. For Zn, which is a tracer of fossil fuel or biomass (wood) combustion activity, no correlation was found. Graphical abstract.

Influence of mining activities on groundwater hydrochemistry and heavy metal migration using a self-organizing map (SOM)

Tongling is a typical metal ore concentration area in the Yangtze Metallogenic Region. Years of mining activities have resulted in serious regional groundwater problems. Therefore, it is of great significance to systematically study the impact of mining activities on the local groundwater. In this paper, a self-organizing map (SOM) calculation and stable isotopes were used to illustrate groundwater hydrochemistry and heavy metal migration, especially concerning Fe, based on the test results of 92 groundwater samples from the study area. Due to mining activities and acid mine drainage (AMD), SO4–Ca-type groundwater with high total dissolved solids (TDS) and low pH values was mainly distributed in the mining areas. In the runoff area, carbonate neutralization and runoff rates were accelerated, while the groundwater TDS gradually decreased and the pH increased. Due to the influence of evaporation and surface water recharging, the major component and heavy metal contents of groundwater increased in the discharge area. With changes in the redox conditions and the influence of variable-valency metals, such as Fe and Mn, heavy metals are easily coprecipitated from groundwater or absorbed by secondary minerals, such as ferrihydrite and birnessite. Therefore, the contents of heavy metals in the groundwater of the study area were relatively low. The main controlling factors determining the groundwater hydrochemical characteristics and heavy metal precipitation are mining activities, redox conditions and rock-water interactions. This study may be helpful for the sustainable development and protection of groundwater resources in the study area and other mining zones in the Yangtze Metallogenic Region.