Arsenic,antimony and bismuth in soil and pasture herbage in some old metalliferous mining areas in England

Soil and pasture herbage samples from some historical metalliferous mining and smelting areas in England were analysed for As, Sb and Bi by ICP-AES using a hydride generation method after ashing with Mg(NO₃)₂. The results showed that As, Sb and Bi concentrations in soils were elevated because of their associations with the Pb-Zn mineralisation in Derbyshire and Somerset, and Sn-Cu mineralisation in Cornwall. The distribution of As, Sb and Bi in soils reflected the chemical nature of different mine waste materials, and on a regional basis clearly reflected the geochemistry of the three mineral provinces. Historical smelting and calcination have caused intensive contamination in soils in the immediate vicinity of these activities. Antimony was highly elevated in soils at an old Pb smelter site in Derbyshire. Although the concentrations of As, Sb and Bi were generally low in the pasture herbage samples examined, the concentrations of As and Sb in herbage often reflected those of the corresponding soils. Soil pH had a large effect on the plant uptake of Bi from soils. The pasture herbage contaminated by soil can be an important exposure pathway of these elements to livestock grazing on contaminated land.     

Arsenic speciation and mobility in surface water at Lucky Shot Gold Mine, Alaska

Historical mining in Alaska has created a legacy of approximately 6,830 abandoned mine sites which include adits, tailing piles and contaminated land that continue to impact surface and groundwater quality through run-off and leaching of potentially toxic metals, especially arsenic (As). One such site is the Lucky Shot Gold Mine in Hatcher Pass, south-central Alaska, which operated from 1920 until 1942, mining gold-bearing quartz veins hosted in a Cretaceous tonalite intrusion. Arsenopyrite (FeAsS) and pyrite (FeS₂) present in the quartz veins contribute to elevated As levels in water draining, abandoned mine adits. As future underground mining at Lucky Shot may further adversely impact water quality, baseline geochemical studies were undertaken to assess As mobility in the vicinity of the mine adits. Water samples were collected from streams, adits and boreholes around the mine and analysed for major and minor elements using inductively coupled plasma-mass spectrometry (ICP-MS) and for anions by ion chromatography (IC). Arsenic species separation was performed in the field to determine the ratio of inorganic As(III)/As(V) using anion-exchange chromatography, following established methods. It was determined that water draining the adits had elevated levels of As roughly seventy times the United States Environmental Protection Agency Drinking Water Standard of 10?μg?L^?1, although this was rapidly diluted downstream in Craigie Creek to <2?μg?L^?1. Adit and surface water pH was circum-neutral and displayed no characteristics of acid mine drainage. Despite being well oxygenated, As(III) is the dominant As species in adit water, accounting for close to 100?% of total As. The proportion of As(V) increases downstream of the adits, as some As(III) is oxidized, but the speciation enhances arsenic mobility at the site. The δ¹⁸O measurements indicate that the water in the system has a short residence time as it is very similar to meteoric water, supporting the observation that the predominance of As(III) in adit water results from the lack of thermodynamical equilibrium being attained and preferential absorbance of As(V).     

Metals and metalloids in PM10 in Nandan County,Guangxi, China,and the health risks posed

Intense mining, smelting, and tailing activities of polymetallic ore deposits have affected the environment in Nandan County, Guangxi, China. Samples of particulates with aerodynamic diameters low or equal 10 μm (PM₁₀) were collected in Nandan County to investigate the concentrations of and health risks posed by 17 metals and metalloids in the PM₁₀. The metal and metalloid concentrations were lower than those found in other industrial cities. The mean Cr concentration was 7.48 ng/m³. Significant higher metal and metalloid concentrations were found in PM₁₀ from mining areas (Dachang and Chehe) than from the control area (Liuzhai) (p < 0.05). Principal component analysis indicated that the main sources of Ba, Co, Cr, Fe, K, Mg, Mo, Na, and Sr were resuspension of the soil produced through mineral erosion, the main sources of As, Cd, Cu, Pb, Sb, and Zn were smelting and mining activities, and the main source of Ni was fossil fuel combustion. Higher non-carcinogenic and carcinogenic risks were posed in Dachang and Chehe than in Liuzhai. The non-carcinogenic risks posed to adults and children by individual metals and metalloids in PM₁₀ at all the sites were low, but the non-carcinogenic risks posed to children by all the metals and metalloids together exceeded the safe level (i.e., risk value > 1). The carcinogenic risks posed by Cd, Ni, and Pb were negligible at all sites, while As, Co, and Cr posed potential carcinogenic risks to the residents.

     

The impact of artisanal gold mining,ore processing and mineralization on water quality in Marmato,Colombia

Marmato, Colombia, has been an important centre of gold mining since before the first Spanish colonizers arrived in 1536. The Marmato deposit is hosted in a dacite and andesite porphyry stock as sheeted sulphide-rich veinlet systems. The district is currently experiencing a surge in both major mining projects and artisanal mining, driven by sustained high gold prices. Ore from small-scale and artisanal gold mining is processed in numerous small mills (entables) around Marmato, which impact surface water quality through the discharge of milled waste rock slurry, highly alkaline cyanide-treated effluent, and high dissolved metal loads. To investigate the impact of artisanal mining and ore processing, water samples were collected in January 2012 from streams around Marmato. The average dissolved metal concentrations in impacted streams were Zn, 78 mg L^?1; Pb, 0.43 mg L^?1; Cu, 403 µg L^?1 Cd, 255 µg L^?1; As, 235 µg L^?1; Ni, 67 µg L^?1; Co, 55 µg L^?1; Sb, 7 µg L^?1; and Hg, 42 ng L^?1, exceeding World Health Organization drinking water guidelines. In addition, arsenic speciation was conducted in-situ and indicated that 91–95% of inorganic arsenic species is in the form of As(V). Spatial analysis of the data suggests that entables processing ore for artisanal miners are the main contributor to water pollution, with high sediment loads, alkalinity and elevated concentrations of dissolved arsenic, cadmium, mercury and lead, caused by the processing of gold-bearing sulphides in the entables. Geochemical data from surface water were compared to a comprehensive data set of whole rock analyses from drill core and channel samples from the deposit, indicating that the deposit is significantly enriched in gold, silver, lead, zinc, arsenic, antimony, and cadmium compared to crustal averages, which is reflected in the surface water geochemistry. However, elevated mercury levels in surface water cannot be explained by enrichment of mercury in the deposit and strongly suggest that mercury is being added to concentrates during ore processing to amalgamate fine gold.

     

Environmental geochemistry study of arsenic in Western Hunan mining area,P.R. China

The geochemical characteristics of arsenic in the soil of the Western Hunan mining area of P.R. China were systematically studied. The results show that the strata of Western Hunan are rich in arsenic and that Western Hunan is a geochemically abnormal region for arsenic. The experimental study on speciation in the strata also indicates that the speciation of arsenic in the Neoproterozoic-Cambrian strata are mainly easily transferred speciation (exchangeable, carbonate-bound, sulfides-bound), which are approaching or exceed 60%. Arsenic content in the main soil of Western Hunan is in the range of 8.8–22.8 μg g⁻¹, the mean value is 16.1 μg g⁻¹, which is larger than the arsenic background value of Hunan soil. The distribution of rock with high arsenic content or high easily transferred arsenic speciation is consistent with the distribution of high arsenic content soil. In the mining region, part soils and river/brook waters were polluted by mine tailings and mining/smelting waste water. The arsenic content in polluted paddy soils and river/brook water is 46.26–496.19 μg g⁻¹, 0.3–16.5 mgL⁻¹, respectively. The positive abnormality and pollution of arsenic in the soil and water affects the arsenic content of the crop and the inhabitants’ health.     

Distribution and phytoavailability of antimony at an antimony mining and smelting area,Hunan, China

An investigation of the distribution, fractionation and phytoavailability of antimony (Sb) and other heavy metals in soil sampled at various locations in the vicinity of a Sb mine revealed elevated levels of Sb, most certainly due to the mining activities. The concentration of Sb in the soil samples was 100.6–5045 mg kg⁻¹; in comparison, the maximum permissible concentration for Sb in soil in The Netherlands is 3.5 mg kg⁻¹, and the maximum permissible concentration of pollutant Sb in receiving soils recommended by the World Health Organization is 36 mg kg⁻¹. The soil sampled near the Sb mine areas had also contained high concentrations of As and Hg. Root and leaf samples from plants growing in the Sb mine area contained high concentrations of Sb, with the concentration of Sb in the leaves of radish positively correlating with Sb concentrations in soil. The distribution of Sb in the soil showed the following order: strongly bound to the crystalline matrix > adsorbed on Fe/Mn hydrous oxides, complexed to organic/sulfides, bound to carbonates > weakly bound and soluble. Solvents showed varying levels of effectiveness in extracting Sb (based on concentration) from the soil, with , in decreasing order. The concentration of easily phytoavailable Sb was high and varied from 2.5 to 13.2 mg kg⁻¹, the percentage of moderately phytoavailable Sb ranged from 1.62 to 8.26%, and the not phytoavailable fraction represented 88.2–97.9% of total Sb in soils.     

Comparison of masking agents for antimony speciation analysis using hydride generation atomic fluorescence spectrometry

A sensitive atomic spectrometric method for the redox speciation analysis of Sb in water is described. The proposed method is based on the selective generation of stibine from Sb(III) in a continuous flow system using non-dispersive atomic fluorescence spectrometry for detection. The effects of the HCl concentration on the fluorescence intensities of Sb(III) and Sb(V) were investigated. The results indicated that atomic fluorescence emission due to Sb(V) can constructively interfere with the determination of Sb(III). For the determination of Sb(III), four compounds were tested as masking agents to inhibit the generation of stibine from Sb(V). The effects of the concentrations of the masking agents and of HCl on the fluorescence signals from Sb(III) and Sb(V) were studied. The results indicated that citric acid and NaF can successfully suppress hydride generation from Sb(V). To evaluate the developed methodology and the influence of the matrix, the recovery of Sb(III) from natural water that was spiked with different Sb(III) and Sb(V) concentrations was tested.     

Enrichment and exposure assessment of As,Cr and Pb of the soils in the vicinity of Stawell,Victoria, Australia

Stawell Gold Mine in NW Victoria, Australia, mines ores that contain large concentrations of As and significant quantities of the metals Pb and Cr. The aim of this research was to understand the dispersion, enrichment and probable exposure of these potentially hazardous elements around the mine site. Fifty-five surface soil samples were collected near the mine (<15 km) and analysed by ICP-MS/OES following bioavailable and four-acid extractions. Soils near the mine show greater concentrations of As, Cr and Pb than those near a regionally determined background. This is attributed to the combination of a natural geochemical halo around mineralization and anthropogenic dispersion due to mining and urbanization. Total As concentrations were between 16 and 946 mg kg⁻¹ near the mine in a regional background of 1–16 mg kg⁻¹. Total Cr concentrations were between 18 and 740 mg kg⁻¹ near the mine in a regional background of 26–143 mg kg⁻¹. Total Pb concentrations were between 12 and 430 mg kg⁻¹ near the mine in a regional background of 9–23 mg kg⁻¹. Dispersion of contaminant elements from the present ore processing is <500 m. The most enriched soils occur close to the town and are unrelated to present mining practices. The bioavailable As, Cr and Pb, soil ingestion rates and Risk Reference Doses were used to estimate health risks. An average toddler (12 kg) would need to consume at least 1.5 g, and most likely 12 g, of soil per day to show some symptoms of As toxicity. The maximum measured bioavailable As would pose a risk at average ingestion rates of 200 mg per day. Individuals with soil-eating disorders would exceed the safe daily consumption limits for As, and potentially Cr and Pb. Small children are not typically exposed to soil everyday, very few have soil eating disorders, and, therefore, the health risk from the soils around the mine is minimal.     

Heavy metal contamination of paddy soils and rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) from Kočani Field (Macedonia)

This research focuses on the heavy metal contamination of the paddy soils and rice from Kočani Field (eastern Macedonia) resulting from irrigation by riverine water impacted by past and present base-metal mining activities and acid mine drainage. Very high concentrations of As, Cd, Cu, Pb and Zn were found in the paddy soils (47.6, 6.4, 99, 983 and 1,245 μg g⁻¹) and the rice (0.53, 0.31, 5.8, 0.5 and 67 μg g⁻¹) in the western part of Kočani Field, close to the Zletovska River, which drains the mining facilities of the Pb–Zn mine in Zletovo. In terms of health risk, the observed highest concentrations of these elements in the rice could have an effect on human health and should be the subject of further investigations.     

Impact of mining activities on soils in a semi-arid environment: Sierra Almagrera district, SE Spain

Field and laboratory-column studies were undertaken in order to investigate soil contamination derived from past mining activity in the Sierra Almagrera (SA) district in southeast Spain. The tailings, soil and sediment samples that were collected showed high concentrations of Ag, As, Ba, Cu, Pb, Sb and Zn when analyzed. The mean concentrations of these elements in the tailings were 29.8, 285.4, 54000, 57.7, 2687.5, 179.0 and 2269.0 ppm, respectively. In the soil samples these decreased to 14.3, 96.9, 24700, 37.5, 1859.1, 168.5 and 815.7 ppm, respectively. Geochemical analyses demonstrated high levels of As, Pb and Zn which were above the intervention values set forth in the Andalusian Regulations for Contaminated Soils for As (>50 ppm), Pb (>500 ppm) and Zn (>2000 ppm). Column experiments and mineralogical studies suggest that the dissolution of sulfates and other secondary phases, accumulated in soils and waste-sites during the dry season, acts to control the mobility of metals. The elution curves obtained from column experiments showed a mobilization of Ba, Cu, Pb and Zn, while a low mobility was seen for Ag, As and Sb.     

Impact of mining activities on soils in a semi-arid environment: Sierra Almagrera district, SE Spain

Field and laboratory-column studies were undertaken in order to investigate soil contamination derived from past mining activity in the Sierra Almagrera (SA) district in southeast Spain. The tailings, soil and sediment samples that were collected showed high concentrations of Ag, As, Ba, Cu, Pb, Sb and Zn when analyzed. The mean concentrations of these elements in the tailings were 29.8, 285.4, 54000, 57.7, 2687.5, 179.0 and 2269.0 ppm, respectively. In the soil samples these decreased to 14.3, 96.9, 24700, 37.5, 1859.1, 168.5 and 815.7 ppm, respectively. Geochemical analyses demonstrated high levels of As, Pb and Zn which were above the intervention values set forth in the Andalusian Regulations for Contaminated Soils for As (>50 ppm), Pb (>500 ppm) and Zn (>2000 ppm). Column experiments and mineralogical studies suggest that the dissolution of sulfates and other secondary phases, accumulated in soils and waste-sites during the dry season, acts to control the mobility of metals. The elution curves obtained from column experiments showed a mobilization of Ba, Cu, Pb and Zn, while a low mobility was seen for Ag, As and Sb.     

铁矿区水环境样品对秀丽隐杆线虫的毒性研究

矿区环境问题是近年来各研究领域关注的焦点。为探究矿区水环境潜在的生物安全性问题,以安徽省霍邱县大型铁矿区地表水体为研究对象,以秀丽隐杆线虫作为实验动物模型,并以其生长和生殖发育作为生物检测终点,考察了线虫对该矿区周边5个地表水样品的毒性效应的响应。结果表明,矿区水环境样品对线虫的生长和生殖发育具有明显的损伤效应,且这种损伤效应的大小与水样采集点距离采矿区的远近以及水样中主要污染物的含量密切相关。进一步通过主成分分析发现,总铁、可溶性铁、铜、铬和砷是环境水样造成线虫毒性效应的主要影响因子。上述研究结果为铁矿区水环境生物安全性的监测和评价提供了一种新的技术方法和新的视角,并为铁矿区健康风险规避提供新的思路和理论基础数据。     

Fractionation and speciation of arsenic in fresh and combusted coal wastes from Yangquan, northern China

In this study, the content and speciation of arsenic in coal waste and gas condensates from coal waste fires were investigated, respectively, using the digestion and sequential extraction methods. The fresh and fired-coal waste samples were collected from Yangquan, which is one of the major coal production regions in northern China. High-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) was used to determine the concentrations of four major arsenic species [As(III), As(V), monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA)] in the extracts, while ICP-MS was used to measure total As content. Arsenic content in the investigated coal wastes and the condensate ranges between 23.3 and 69.3 mg/kg, which are higher than its reported average content in soils. Arsenic in coal waste exists primarily in the residual fraction; this is followed in decreasing order by the organic matter-bound, Fe–Mn oxides-bound, exchangeable, carbonates-bound, and water-soluble fractions. The high content of arsenic in the condensates indicates that combustion or spontaneous combustion is one of the major ways for arsenic release into the environment from coal waste. About 15% of the arsenic in the condensate sample is labile and can release into the environment under leaching processes. The water extractable arsenic (WEA) in the fresh coal waste, fired coal wastes, and the condensate varied between 14.6 and 341 μg/kg, with As(V) as the major species. Furthermore, both MMA and DMA were found in fresh coal wastes, fired coal wastes, and the condensate.     

Geophysical investigations for evaluation of environmental pollution in a mine tailings area

Sulfide-containing mill wastes of the Komsomolsk ore processing plant situated in the Kemerovo region (Russia) were examined in 2013–2015. Multipurpose studies of the mine tailings determined the composition of waste, pore water, mine drainages, and affected groundwater. Electrical resistivity tomography was used to trace the geoelectric zoning of the waste samples. Layers with low resistivity indicated areas with pore spaces filled with highly mineralized solutions with Fe, Cu, Zn, Cd, As, and Sb at total concentrations of up to 50 g/L. Anomalous zones can be specified as ‘geochemical barriers’ – specific layers where the mobility of the elements is reduced due to pH conditions, redox potential, and Fe(III) hydroxide precipitation. The zones of increased conductivity in oxidized mine tailings indicated local areas with high acid production potential and coexisting acidic pore solution. In non-oxidized tailings, high conductivity of the mineral skeleton was observed. There was a migration of drainage outside the tailings, its direction monitored by geophysical data. Chemical analysis confirmed that the concentrations of As in groundwater samples were higher than the maximum permissible concentration.     

Trace element geochemistry of the Keana brines field,middle Benue trough,Nigeria

A trace elements study of various samples from the Keana brines field, middle Benue Trough was carried-out to determine the extent to which Pb–Zn–S and BaSO₄ mineralisations have affected the quality of the brines and the waters in the area. Different sample media such as well-water, pond water, brine spring pool water, stream water, stream sediments etc. were analysed. Geochemical results show that Cu, Zn, Pb, As and S are concentrated in the waters (0.3, 0.36, 0.05, 0.07 and 1 1.5 ppm respectively). These elements are more concentrated in both the spring and pond waters, suggesting that the spring water could have acted as the transport medium for these elements released from deep-seated sources. Transitions elements (Ti, V, Cr, Fe, Co, Ni and Sr) are concentrated in the waters. Compared to the World Health Organization (WHO) admissible limits, the well waters present very high concentrations in Cd (0.56 ppm) and Sb (0.40 ppm) (200× and 70× WHO admissible values respectively). There is a preferential concentration of transition elements (Ti, V, Fe, Co and Ni) in the sediments (41.38, 362, 52.21, 269 and 54 ppm respectively) than in the waters (0.70, 0.05, 5.6, 0.04 and 0.02 ppm respectively). Similarly, Cu, Zn, Pb and As are concentrated in the sediments (44, 72, 41 and 14 ppm respectively). The concentrations of transition elements (Ti, V, Cr, Fe, Co and Ni) in the refined salt were highly elevated (784, 363, 283, 105, 59.2 and 42.6 ppm respectively) (7000–10,000× well water). Similarly, the concentrations of As, Pb, Br and Sr in the refined salt were also alarming (11.6, 16.4, 16.4 and 122 ppm respectively), (1000, 700, 3000 and 20,000× well water values respectively). S on the other hand is absent. One of the striking features is the absence of I, Cd, Sb and Se in the refined salt crystals which were detected in the waters and the brines. Compared to WHO admissible values, the refined salt crystal concentrations for Ni (426 ppm) and Cr (283 ppm) were also very high (2000× WHO values respectively) and to a lesser extent Cu (26.9 ppm) and Zn (21.7 ppm) (12 and 7× WHO values respectively).     

In-situ electrochemical measurements of total concentration and speciation of heavy metals in acid mine drainage (AMD): assessment of the use of anodic stripping voltammetry

We assessed the use of anodic stripping voltammetry (ASV) for in-situ determinations of both total concentration and speciation of dissolved heavy metals (Cd, Cu, Pb and Zn) in acid mine drainage (AMD). In the Kwangyang Au–Ag mine area of South Korea, different sites with varying water chemistry within an AMD were studied with a field portable anodic stripping voltammeter. Anodic stripping voltammetry after wet oxidation (acidification) was very sensitive enough to determine total concentration of dissolved Cd because Cd was dominantly present as ‘labile’ species, whilst the technique was not so effective for determining total Cu especially in the downstream sites from the retention pond, due to its complexation with organic matter. For dissolved Pb, the concentrations determined by ASV after wet oxidation generally agreed with those by ICP-AES. In the downstream samples (pH>5), however, ASV data after wet oxidation were lower than ICP-AES data because a significant fraction of dissolved Pb was present in those samples as ‘inert’ species associated with colloidal iron oxide particles. The determination of total dissolved Zn by ASV after wet oxidation appeared to be unsatisfactory for the samples with high Cu content, possibly due to the interference by the formation of Zn–Cu intermetallic compounds on the mercury coated electrode. In AMD samples with high dissolved iron, use of ultraviolet irradiation was not effective for determining total concentrations because humate destruction by UV irradiation possibly resulted in the removal of a part of dissolved heavy metals from waters through the precipitation of iron hydroxides.     

Chemical availability of arsenic and antimony in industrial soils

Total concentrations and extractable fractionations of As and Sb were determined in soil samples from former mining sites in Scotland and Italy. Pseudo-total levels of As and Sb in the sample were between 50–17,428 mg/kg and 10–1,187 mg/kg (Scotland), and 16–691 mg/kg and 1.63–11.44 mg/kg (Italy). Between 0.001–0.63% and <0.001−8.82% of the total soil As and Sb, were extractable using, a single extraction bioavailability estimate. Data from an As-specific extraction procedure revealed that up to 60% of As was associated to amorphous Fe-Al oxyhydroxide phase in all soils. A non-specific-sequential extraction test also showed As to be strongly associated with Fe (and Al) oxyhydroxides at both locations. In the case of Sb, in addition to the crystalline Fe-oxide bound Sb the Al-silicate phase also appeared to be significant. At both sites Sb appears to be chemically more accessible than As with consistent availability despite the varied origin and host soil properties.     

Distribution,geochemistry, and mineralogy of aerosols in the Angouran Mine area,northwest Iran

The Angouran Mine, located in northwest Iran, is the largest Zn–Pb producer in the Middle East. This study was designed to investigate the distribution, geochemistry, and mineralogy of the aerosols in the mining area and to assess their likely health impacts on the local residents. For this purpose, 36 aerosol samples were collected from 2014 to 2015 at nine sites located in mine district and upwind and downwind directions. The concentration of potentially toxic elements in the aerosols was determined using AAS instrument. Size, morphology, and mineralogy of the particles were studied using SEM and EDX spectra. The results indicate that the amount of total suspended particles in upwind, mine district, and downwind sites is 95.5, 463.4 and 287.5 µg/m³, respectively. The concentrations of PM_2.5 in the three locations are 8.9, 134.7, and 51.8 µg/m³, whereas the PM₁₀ contents are 2.9, 74.4, and 15.5 µg/m³, respectively. These observations point to the impact of mining activities on the concentration of aerosols in the local atmosphere. The values of air quality index also show the probable effects of the mining activities on the health of the local populations, especially for allergic peoples. The average concentration of Zn in the samples collected from the mining district (290 µg/kg) is much higher than its value in the upwind sites (27 µg/kg). The highest concentration of As (70 µg/kg), Cd (10 µg/kg), and Pb (3 µg/kg) is in downwind sites, which shows the negative impact of mining activities on the local air quality. Temporally, the highest concentration of the studied elements is recorded in spring season, especially for PM_2.5 collected in downwind stations. Based on the results of SEM and EDX spectra, three groups of minerals, i.e., carbonates, silicates, and sulfides, are present in the aerosol particles, confirming the local source for the aerosols. SEM analyses showed that the aerosol particles with dissimilar chemical composition have different morphologies such as irregular, rounded, elongated, and angular. On the basis of the results, the mining activities in the Angouran Zn–Pb Mine may have various short- and long-term consequences on the public health, especially due to high amount of the finer particles (PM_2.5) and the higher concentration of the potentially toxic elements in PM_2.5 which can penetrate into the lungs.

     

Arsenic,antimony, and other trace element contamination in a mine tailings affected area and uptake by tolerant plant species

The study was conducted to characterize mineralogical and elemental composition of mine tailings in order to evaluate the environmental hazards, and identify the metal accumulation potential of native plant species from São Domingos mine, one of the long-term activity mines of the Iberian Pyrite Belt dating back to pre-Roman times. The mine tailings including soils and different plant species from São Domingos were analyzed for determination of tailings characteristics and chemical element contents in tailings and plants. The large amounts of mining wastes are causing significant adverse environment impacts due to acid mine drainage production and mobilization of potentially toxic metals and metalloids in residential areas, agricultural fields, downstreams, and rivers. The typical mineralogical composition is as follows: quartz, micas, K-feldspar, olivine-group minerals, magnetite, goethite, hematite, jarosite, and sulfides. The mine tailings were highly contaminated by As, Ag, Cr, Hg, Sn, Sb, Fe, and Zn; and among them, As and Sb, main contaminants, attained the highest concentrations except Fe. Arsenic has exhibited very good correlations with Au, Fe, Sb, Se, and W; and Sb with As, Au, Fe, Se, Sn, and W in tailings. Among the all plant species, the higher concentrations of all the metals were noted in Erica andevalensis, Erica australis, Echium plantagium, and Lavandula luisierra. Considering the tolerant behavior and abundant growth, the plant species Erica australis, Erica andevalensis, Lavandula luisierra, Daphne gnidium, Rumex induratus, Ulex eriocladus, Juncus, and Genista hirsutus are of major importance for the rehabilitation and recovery of degraded São Domingos mining area.