Metal Mining Areas Research Articles

Effects of Different Land Use Types on Microbial Community Diversity in the Shizishan Mining Area

Soil microorganisms play an important role in ecosystem function. Soil microbial community structure can be used to feed back the status of heavy metal pollution in soil at different functional areas of mines related to mining activities. Samples of four different land use types (vegetable garden, tailings reservoir, heap mining area, and dressing area) were collected in the Shizishan mining area, Tongling, Anhui Province, to determine the effect of heavy metal pollution on microbial community structure. Soil physical and chemical properties and heavy metal contents of the four different land use types were measured, and soil microbial community abundance and structure diversity were analyzed by Illumina MiSeq high-throughput sequencing technology. The results show that there are significant differences in physical and chemical properties between different regions. The comprehensive pollution index of Nemerow is heap mining area (7.28) > dressing area (6.99) > tailings reservoir (6.55) > vegetable garden (5.92). The distribution of microbial community abundance and structure diversity was tailings reservoir > dressing area > vegetable garden > heap mining area. In addition, principal coordinates analysis (PCoA), canonical correspondence analysis (CCA), and correlation analysis showed that land use type, soil pH and heavy metal content had significant effects on the microbial community. The dominant soil microbial communities at the phylum level were Proteobacteria, Bacteroidetes, Acidobacteria, and Actinobacteria, at the class level were β-Proteobacteria, α-Proteobacteria, and γ-Proteobacteria, and at the genus level were Flavobacterium, Kaistobacter, and Ramlibacter. The bacteria that are more tolerant to heavy metals are Proteobacteria, Firmicutes, β-Proteobacteria, and Kaistobacter. These results have deepened our understanding of microbial changes and aggregation patterns in soils of heavy-metal-contaminated mining areas. This study can provide bacterial species and theoretical basis for bioremediation of heavy metal mining areas.

Assessment of Heavy Metal Exposure to Residents around Abandoned Metal Mines

TPS 621: Exposure to metals, Johan Friso Foyer, Floor 1, August 26, 2019, 3:00 PM - 4:30 PM Background/Aim: Abandoned metal mines are areas of great concern for the health effects of residents due to hazardous substances such as heavy metals. The purpose of this study was to compare the exposure of heavy metals to residents of the abandoned metal mines and general population through National Health Survey. Methods: We examined 4,499 residents of the abandoned mines of 2nd phase health effects survey of abandoned metal mines (AMS, ‘13~’17). We used data from the Korea national health and nutrition examination survey (KNHANES, ‘12, ‘13, ‘16) and the Korean national environmental health survey (KNEHS ‘09~’15). Based on the gender and age distribution of AMS, KNHANES (n=980) and KNEHS (n=1,412) were randomly sampled for the same distribution. The geometric mean concentrations (95% confidence interval) of blood lead, blood cadmium, urinary cadmium, and urinary arsenic concentration were presented, the excess proportion was given by reference to the 95th percentile concentration of the general population. Results: The geometric mean concentration of lead in blood was significantly higher in AMS than those of the general population (AMS: 2.27(2.24-2.30)a μg/dL; KNHANES: 2.11(2.06-2.17)b μg/dL; KNEHS: 2.23(2.18-2.29)b μg/dL; p<0.001). The geometric mean concentration of blood cadmium in AMS was also higher than those of the general population (AMS: 1.42(1.40-1.44) μg/L; KNHANES: 1.24(1.20-1.28) μg/L; p<0.001), and cadmium in urine was remarkably different and statistically significant (AMS: 1.47(1.42-1.53) μg/L; KNEHS: 0.47(0.45-0.49) μg/L; p<0.001). Conclusions: The concentration of heavy metals in residents of the abandoned metal mines was higher than those of the general population. We considered the routes of exposure of crops ingestion, groundwater intake, soil contact, and inhalation of scattered dust in contaminated environment. Therefore, continuous individual and national management are needed to evaluate the health risks of residents in the abandoned metal mine areas.

Potential Ecological Risk and Health Risk Assessment of Heavy Metals and Metalloid in Soil around Xunyang Mining Areas

Xunyang is rich in various metal minerals and is one of the four major metal mining areas in Shaanxi province, China. To explore the effects of soil heavy metals and metalloid pollution on the environment and human health around the mining areas, four places—Donghecun (D), Gongguan (G), Qingtonggou (Q) and Nanshagou (N)—were selected as the sampling sites. Potential ecological risk (PER) and health risk assessment (HRA) models were used to analyze the environmental and health risks around the mining areas. The concentration of heavy metals (Cd, Cr, Pb, Zn, Ni, Cu, Hg) and metalloid (As) in cultivated land in the vicinity of Xunyang mining areas indicated that, except for Cu, the remaining elements detected exceeded the threshold values at some sites. The geo-accumulation index (IGeo) revealed that soils in G and Q could be identified as being extremely contaminated. PER indicated that there was significantly high risk at G and Q for Hg. In N, Pb recorded the highest E r i , which also demonstrates a considerable pre-existing risk. HRA indicated that the hazard index (HI) for both carcinogenic and non-carcinogenic risks was much higher among children than among adults, and the ingestion pathway contributed the greatest risk to human health, followed by the dermal pathway and inhalation. Because the HI values of the metals and metalloid in the study areas were all lower than 1, there was no significant non-carcinogenic risk. However, the carcinogenic risk for Cr is relatively higher, surpassing the tolerable values in G, Q, and N. This study analyzed the ecological risks and human health risks of heavy metals and metalloid in farmland soils near the sampling mining areas, and demonstrated the importance of environmental changes caused by land development in the mining industry.

Source apportionment of heavy metal and their health risks in soil-dustfall-plant system nearby a typical non-ferrous metal mining area of Tongling, Eastern China

The agricultural land-atmospheric dustfall-plant system around the mining area is at high risks of heavy metal pollution caused by mining-smelting activities. In this study, 118 samples (including rhizospheric soils, background soils, soil-forming parent rocks, crops, vegetables, medicinal plants and atmospheric dustfall) were collected nearby Tongling Cu-Fe-Au mining area, Eastern China. We studied the concentrations, migration, sources, and health risks through consumption of two main crops (corn and rice), six kinds of vegetables, and medicinal plants (Fengdan, Paeonia ostii) for six metal elements (Cu, Zn, Cr, Cd, Pb and Hg). Results revealed Cr and Cd in soils, and Cd, Cr, Pb, Cu and Zn in dustfall showed a relatively high contamination degree. The mean contents of Cr and Pb in corn kernels, as well as Cd, Cr and Pb in rice grains and all vegetables, and Cr in Fengdan cortex moutan exceeded the corresponding food safety limits in China. The transfer capability of Cr in corn kernels and rice grains, Pb in edible vegetables, and Cd in cortex moutan were the strongest, respectively. Health risk assessment results showed Cr had the greatest non-carcinogenic risk, followed by Pb and Cd. The results of pearson's correlation analysis (CA), hierarchical cluster analysis (HCA), and principal component analysis (PCA) indicated Zn-Cr, Pb and Cd-Cu-Hg in the plants might derive from different geochemical end-members. Source apportionment based on lead isotope showed that mining-smelting activities were the major source of Pb in atmospheric dustfall and agricultural soils, with the average contribution rates of 66% and 50%, respectively. Vehicle emissions from diesel fuels (50%–68%) and mining-smelting activities (16%–25%) contributed mainly to Pb accumulation in plants. Hence, our study suggested the accumulations of Pb in plants might be mainly from the direct foliar uptake of atmospheric Pb related to vehicle emissions and mining-smelting activities.

Harmful and nutrient elements in paddy soils and their transfer into rice grains (Oryza sativa) along two river systems in northern and central Vietnam.

Thirty soil samples and 24 corresponding unpolished rice samples along the Red and Huong Rivers in northern and central Vietnam respectively, were analyzed in order to evaluate (a) soil geochemistry, (b) factors that determine the transfer of harmful and nutrient elements from soils into rice grains, (c) health risk to the local population through rice consumption. The concentrations of As, Bi, and U in the soils of this area are higher relative to those of average shale probably due to natural redox-related processes. Also, Zn, Ce, Th, La, Sn, Pb, and Cd are accumulated in some soils because of mining activities or industrial wastewater application. Arsenic concentrations exceed the Vietnamese allowable limit of 15mgkg-1 in 80% of the tested soils. Twelve percent of the unpolished rice grains surpass the permissible maximum concentration of 0.2mgCdkg-1 grain dry matter by FAO/WHO and European Union, and all samples are below the Pb limit. The daily intake of As is within the range of the tolerable intake levels proposed by the European Food Safety Authority. Influences of soil parameters such as pH value, contents of soil organic matter, oxides/hydroxides of Al, Fe, and Mn cause a broad spread of transfer factors from soil to grains. Positive trends exist between the transfer factors within the groups (a) As, Sb, and U, (b) Co, Cu, Ni, and Zn, (c) Cd and Mn which indicate similar influences of soil parameters on their uptake. We propose that the allowable Cd maximum concentration for rice should be set to less than 0.2mgkg-1. The analysis of As and Cd concentrations in soils and corresponding rice grains as well as the soil pH value should be made obligatory in order to prevent intoxication. In addition, critical elements from nonferrous metal mining and industrial areas should also be evaluated.

Exposure assessment for the abandoned metal mine area contaminated by arsenic

Among the results of community health impact assessments completed in 2014, residents of the Indae abandoned metal mine area showed high average urinary concentrations of harmful arsenic (As), at 148.9 µg/L. The concentration of harmful As was derived as the sum of As(V), As(III), MMA, and DMA concentrations known to be toxic. In this area, mining hazard prevention work was not carried out and the pollution source was neglected, and the health effect of the residents due to arsenic exposure was concerned. We re-assessed As exposure levels and tried to identify exposure factors for residents of this area. Analysis of the soil, sediment, and river water to assess the association between the soil of the Indae abandoned metal mine area and the soil in residential areas confirmed a correlation between Pb and As concentrations in the soil. Since Pb and As behave similarly, the use of the stable Pb isotope ratio for assessment of the pollution source tracking was validated. In the 3-isotope plot (207/206Pb vs. 208/206Pb) of soil samples in this area, a stable Pb isotope ratio was located on the same trend line, which confirmed that the soil in the residential area was within the area of influence of the Indae abandoned metal mine. Therefore, we judged that the pollution source of As was the Indae abandoned metal mine. The results by As species were As (III) 1.45 μg/L, As (V) 0.74 μg/L, monomethylarsonic acid (MMA) 2.43 μg/L, dimethylarsinic acid (DMA) 27.63 μg/L, and arsenobetaine 88.62 μg/L. The urinary harmful As was 31.92 μg/L, much lower than the 148.9 μg/L reported in a 2014 survey, due to the implementation of a multi-regional water supply in November 2014 that restricted As exposure through drinking river water. However, concerns remain over chronic exposure to As because As in river water used for farming and in agricultural soil still exceeds environmental standards; thus, ongoing work to address hazards from former mining areas and continued environmental monitoring is necessary.

Distribution characteristics and pollution assessment of soil heavy metals over a typical nonferrous metal mine area in Chifeng, Inner Mongolia, China

The spatial distribution characteristics of heavy metals (As, Cd, Cu, Pb, and Zn) in a typical lead–zinc mine located in Inner Mongolia were studied by applying mathematical statistics and the ArcGIS spatial interpolation analysis. The Nemerow index and potential ecological-risk index were applied to the pollution assessment of heavy metals from the soil in accordance with the Environmental Quality Standard for Soils of China (grade 2) and background value for heavy metals. Results indicated that the average concentrations of As, Cd, Cu, Pb, and Zn were 82.39, 1.01, 33.47, 96.47, and 254.64 mg kg−1, respectively, and these values were higher than the regional background values in the studied scale. The average single-factor index (Pi) values of As, Cd, Cu, Pb, and Zn were 6.46, 6.61, 1.81, 3.93, and 4.02, respectively, when the regional background value was used as the assessment standard. Based on the Nemerow pollution index (PN), all areas over the mine were in moderate or heavy pollution. The result of potential ecological-risk assessment showed that the mining-activity area and its surrounding areas were in the moderate risk level or above. Pollution was concentrated in the centre mining-activity area of tailing reservoir, concentrator, and waste dumps. The degree of heavy-metal pollution decreased with increased distance from the mining-activity area.

Microbial Reduction of Cr (VI)-loaded Schwertmannite by Shewanella oneidensis MR-1

ABSTRACTMicrobial transformation of sulfate minerals plays an important role in controlling the behavior of heavy metals in mining areas. Here, the anaerobic reduction of Cr (VI)-loaded schwertmannite by Shewanella oneidensis MR-1 (S. oneidensis MR-1) was investigated. The release of ferrous iron (Fe(II)) to the solution demonstrated the microbial reduction of structural Fe(III) from the schwertmannite to Fe(II). The concentration of Cr in solution decreased in all treatments, indicating that no Cr was released to the solution during this bio-reduction process of schwertmannite. The incorporation of chromate into the mineral structure of schwertmannite increased the microbial stability of the mineral, retarding the formation of secondary phases during bio-reduction process. Analysis of the XRD, SEM and fourier transform infrared spectroscopy (FT-IR) results further showed that goethite formed after 3 or 7 days with a lower content (0.22% or 0.37%) of Cr in schwertmannite, while no secondary mineral was observed with a higher concentration of Cr (0.6 wt%) incorporated in schwertmannite until 22 days. These results imply that microbial reduction of Cr(VI)-loaded schwertmannite does not lead to the release of Cr to the solution, and the microbial stability of schwertmannite will be increased by the incorporation of chromate.

Accumulation of Cd and Its Risks in the Soils of the Xijiang River Drainage Basin in Guangxi

To understand the distribution and risk of soil cadmium (Cd) in the Xijiang River drainage basin in Guangxi, a total of 2512 soil samples were collected nonferrous metal mining area, farmland (paddy soils and dryland soils) and the background soils, in the Xijiang River drainage basin in Guangxi.The results showed that Cd concentration was 0.514 mg·kg-1 in background soils significantly higher than previously resulted(0.148 mg·kg-1)and that in Guangxi background soil(0.267 mg·kg-1). The geometric average concentration of Cd in dryland soils, paddysoils and mining soils was 0.559, 0.787, 5.71 mg·kg-1, respectively, which were significantly higher than background soils. The Cd concentration exceeded the background soils and baseline by 51.2% and 35.2% in dryland soil, 66.7% and 39.6% in paddy soil, 77.8% and 71.4% in mining soil, high Cd concentration occurred in the Nandan County, Dahua County, Duan County, Huanjiang County and Yizhou City, as well as Liujiang County, These regions have developed severe and even extremely serious pollution, medium-high pollution accumulation and higher-extremely high potential ecological risks. The Cd-pollution in soils in agricultural and mining soils in upstream of Xijiang River in Guangxi is serious, due to mining activities and high Cd geological background. People in the mining area and surrounding areas who live on local crops, vegetables, may expose to the Cd-pollution. It is recommended to further develop a Cd risk assessment through a soil-plant-human system, taking appropriate measures to control risk.

Sediment matrix characterization as a tool for evaluating the environmental impact of heavy metals in metal mining, smelting, and ore processing areas

In this work, the matrix characterization (mineralogy, total and local chemical composition, and total organic (TOC) and inorganic carbon (TIC) contents) of different types of sediments from mining- and metallurgy-influenced areas and the assessment of the impact of the matrix on the association of potentially hazardous metals with the mineral phases of these samples, which affect their mobility in the environment, are presented. For these purposes, sediment samples with different origins and from different locations in the environment were analyzed. Anthropogenic sediments from metal-rich post-flotation tailings (Lintich, Slovakia) represent waste from ore processing, natural river sediments from the Hornád River (Košice, Slovakia) represent areas influenced predominantly by the metallurgical industry, and lake sediments from a water reservoir Ružín (inflow from the Hornád and Hnilec Rivers, Slovakia) represent the impact of the metallurgical and/or mining industries. The total metal contents were determined by X-ray fluorescence (XRF) analysis, the local chemical and morphological microanalysis by scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and the TOC and TIC contents by infrared (IR) spectrometry. The mobility/bioavailability of Cu, Pb, and Zn in/from sediments at the studied areas was assessed by ethylenediaminetetraacetic acid (EDTA) and acetic acid (AA) extraction and is discussed in the context of the matrix composition. The contents of selected potentially hazardous elements in the extracts were determined by the high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS).

An improved estimation model for soil heavy metal(loid) concentration retrieval in mining areas using reflectance spectroscopy

An advanced estimation model CARS-PLS (competitive adaptive reweighted sampling-partial least squares) has been developed for feature extraction and soil contamination analysis. However, this method works well for a single mining area and has limited capacity in coping with the variations from multiple sites. In this paper, we present an improved estimation model, CARS-PLS-SVM, to cope with the nonlinear problem in multiple sites with SVM (support vector machines). We selected two study areas located in metal mining and coal mining areas of north China. A total of 65 soil samples were collected. The heavy metal(loid) concentrations (Cr and As) were determined by inductively coupled plasma-mass spectrometry (ICP-MS) and atomic fluorescence spectrometry (AFS), and the visible and near-infrared spectra of the soil samples were measured with an ASD (Analytical Spectral Devices) field spectrometer (350–2500 nm). Samples were divided into calibration set (n = 41) and validation set (m = 24) according to heavy metal(loid) concentration. After different pretreatment methods, the new features extracted from CARS-PLS are used as the input to model the data further with SVMs. The performance of CARS-PLS-SVM was investigated under seven different pretreatment methods. Results showed that using combination of Savitzky-Golay and standard normal transformation pretreatment method achieved the best accuracy for Cr estimation (coefficient of determination for prediction, Rp2 = 0.9705, root-mean-square error for prediction, RMSEP = 5.0253, residual prediction deviation, RPD = 5.9001, ratio of prediction performance to interquartile range, RPIQ = 11.4043) and for As prediction (Rp2 = 0.9483; RMSEP = 1.2024; RPD = 3.0689; RPIQ = 5.3643). Besides, CARS-PLS-SVM is better than partial least squares (PLS) regression under the same pretreatment methods. Compared with three current state-of-the-art models: wavelet transform PLS (WT-PLS), synergy interval PLS (siPLS), and the CARS-PLS model, CARS-PLS-SVM was found to be superior to the other methods for Cr prediction (Rp2 = 0.9705; RMSEP = 5.0253; RPD = 5.9001; RPIQ = 11.4043) and As prediction (Rp2 = 0.9483; RMSEP = 1.2024; RPD = 3.0689; RPIQ = 11.5.3643). The results demonstrate that compared with other linear models, the nonlinear model CARS-PLS-SVM has the highest precision in soil heavy metal(loid) estimation modeling of multiple mining areas by the use of proper spectral feature extraction from the pretreated spectra.

Combined effects of antimony and sodium diethyldithiocarbamate on soil microbial activity and speciation change of heavy metals. Implications for contaminated lands hazardous material pollution in nonferrous metal mining areas

The combined effects of antimony (Sb) and sodium diethyldithiocarbamate (DDTC), a common organic flotation reagent, on soil microbial activity and speciation changes of heavy metals were investigated for the first time. The results showed that the exchangeable fraction of Sb was transformed to a stable residual fraction during the incubation period, and the addition of DDTC promoted the transformation compared with single Sb pollution, probably because DDTC can react with heavy metals to form a complex. In addition, the presence of DDTC and Sb inhibited the soil microbial activity to varying degrees. The growth rate constant k of different interaction systems was in the following order on the 28th day: control group ≥ single DDTC pollution > combined pollution > single Sb pollution. A correlation analysis showed that the concentration of exchangeable Sb was the primary factor that affected the toxic reaction under combined pollution conditions, and it significantly affected the characteristics of the soil microorganisms. All the observations provide useful information for a better understanding of the toxic effects and potential risks of combined Sb and DDTC pollution in antimony mining areas.

Trace Elements in Soils and Selected Agricultural Plants in the Tongling Mining Area of China.

The quality and safety of agricultural products from metal mining areas are of wide concern. In order to investigate the contents and health risks of trace elements in fruit vegetables planted in metal mining areas, 440 samples of fruit vegetables from 117 vegetable plots were collected from Tongling mining area. Trace element contents in fruit vegetables and soil were measured. The results indicated that the total concentration of trace elements in some of the soil samples exceeded the Grade II national standard in China. Transfer factor (TF) of Cd was the highest (8.360), followed by Zn, Cu, As, and Pb. Estimated daily intake (EDI) of the trace elements, except Cd, were generally below the maximum tolerable daily intake (MTDI). The target hazard quotient (THQ) of Zn for children was more than 1 in some vegetables, suggesting potential health hazards for child population. Total target hazard quotient (TTHQ) of Cu and Zn were also more than 1 through consumption of all vegetables, indicating significant health risks. For both adults and children, hazard index (HI) was more than 1 for the consumption of vegetables. The findings reveal the health risks associated with the consumption of trace elements through the intake of selected vegetables in the population of Tongling.

Risk Assessment of Heavy Metal Pollution in Soils of Gejiu Tin Ore and Other Metal Deposits of Yunnan Province

This paper aims to study three main metal mining areas in Yunnan Province, to summarize and analyze the heavy metal pollution situation in each mining area, and to assess the ecological risk of the mining areas. The results showed that heavy metal pollution existed in different regions of the three mining areas with pollution elements of Cd, As, Cu, Pb, Zn. Risk level, besides Zhen Yuan mining area (class C), for the other two areas was class D, with Beichang mining area in Lanping as the most serious polluted mining area.

Effects of Soil Amendments Application on Growth of Rice Cultivated in Soils Polluted with Heavy Metal(loid) and on the As and Cd Content in Brown Rice

Heavy metal(loid) contamination of rice is the main issue in abandoned metal mine area with regard to food safety. A field study was conducted in mine area to see if soil amendments treatment including calcium superphosphate, sulfur, steel slag and S-containing fertilizer could reduce As and/or Cd content in rice grain and increase the growth of rice. The As content in brown rice reduced to 60% compared to the control only in <TEX>$7.0Mg\;ha^{-1}$</TEX> of steel slag treatment. Cd reduction in rice was thought to be not the effect of amendments but the result from the difference in growth and development of rice plant and this could be ascribed to low soil Cd availability to rice plant. Compared with control, increased rice yield of cultivar Hwanggeumnuri was 1.3~2.2 and <TEX>$1.5Mg\;ha^{-1}$</TEX> in calcium super phosphate and S-containing fertilizer treatment, respectively and the trend was also observed in cultivar Ungwang. However, steel slag treatment reduced the Ungwang yield by <TEX>$0.4{\sim}0.9Mg\;ha^{-1}$</TEX>. Future work will be needed to establish the agricultural measure with which secure the safety and yield of rice simultaneously.

Evaluating water quality and ecotoxicology assessment techniques using data from a lead and zinc effected upland limestone catchment

Point and diffuse sources associated with historical metal ore mining are major causes of metal pollution. The understanding of metal behaviour and fate has been improved by the integration of water chemistry, metal availability and toxicity. Efforts have been devoted to the development of efficient methods of assessing and managing the risk posed by metals to aquatic life and meeting national water quality standards. This study focuses on the evaluation of current water quality and ecotoxicology techniques for the metal assessment of an upland limestone catchment located within a historical metal (lead ore) mining area in northern England. Within this catchment, metal toxicity occurs at circumneutral pH (6.2–7.5). Environmental Quality Standards (EQSs) based on a simple single concentration approach like hardness based EQS (EQS-H) are more overprotective, and from sixteen sites monitored in this study more than twelve sites (>75%) failed the EQSs for Zn and Pb. By increasing the complexity of assessment tools (e.g. bioavailability-based (EQS-B) and WHAM-FTOX), less conservative limits were provided, decreasing the number of sites with predicted ecological risk to seven (44%). Thus, this research supports the use of bioavailability-based approaches and their applicability for future metal risk assessments.

Simultaneous Analysis of 13 Pesticides in Groundwater and Evaluation of its Persistent Characteristics

For this study, groundwater samples for 3 years from 2011 through 2013 were collected at 106 groundwater monitoring site in Korea. These groundwater samples were analyzed for 13 pesticides such as cabofuran, pentachlorobenzene, hexachlorobenzene, simazine, atrazine, lindane (gamma-HCH), alachlor, heptachlor, chlordane (total), endosulfan (1, 2), dieldrin, endrin, 4,4-DDT. The objectives of this study were to determine the detection frequency and their concentrations of 13 pesticides and evaluate the health risk level considering ingestion, inhalation, and skin contact using concentrations of 13 pesticides in groundwater samples. An analysis was used for the simultaneous determination for 13 pesticides using GC-MS. GC-MS was performed on HP-5ms, using helium (1 ml min-1) as carrier gas. The average recoveries of the pesticides were from 92.8% to 120.8%. The limits of detection (LODs) were between 0.004 µg L-1 and 0.118 µg L-1 and the limits of quantification (LOQs) were between 0.012 µg L-1 and 0.354 µg L-1. 106 groundwater wells were selected. 54 wells were from well to monitor background groundwater quality and 52 wells were from well to monitor groundwater quality in industrial or contamination source area. Eight pesticides including pentachlorobenzene, lindane (Gamma-HCH), heptachlor, chlordane (total), Endosulfan (1, 2), dieldrin, endrin, and 4,4-DDT were not detected in groundwater samples. The detection frequency for hexachlorobenzene, alachlor, carbofuran and simazine was 23.4%, 11.4%, 7.3%, and 1.0%, respectively. Atrazine was detected once in 2011. The average concentrations were 0.00423 µg L-1 for carbofuran, 0.000243 µg L-1 for alachlor, 0.00015 µg L-1 for simazine, and 0.00001 µg L-1 for hexachlorobenzene. The detection frequency of hexachlorobenzene was high, but the average concentration was low. In the contaminated groundwater, the detection frequency for hexachlorobenzene, alachlor, carbofuran, simazine and atrazine was 26.1%, 21.3%, 7.1%, 1.9% and 0.3%, respectively. In the uncontaminated groundwater, detection frequency for hexachlorobenzene, carbofuran and alachlor were 20.2%, 7.5%, and 1.9% respectively. Simazine and atrazine were not detected at uncontaminated groundwater wells. According to the purpose of groundwater use, atrazine was detected for agricultural groundwater use. Hexachlorobenzene showed high detection frequency at agricultural groundwater use area where the animal feeding area and golf course area were located. Alachlor showed more than 50% detection frequency at cropping area, pollution concern river area, and golf course area. Atrazine was detected in agricultural water use area. By land use, the maximum detection frequency of alachlor was found near an orchard. For human risk assessment, the cancer risk for the 5 pesticides was between 10-7 and 10-10, while the non-cancer risk (HQ value) was between 10-4 and 10-6. For conclusion, these monitoring study needs to continue because of the possibility of groundwater contamination based on various purpose of groundwater use. Detection frequency and average concentrations of pesticides near the sources of the contamination (S: Agricultural water use area, N: Crops area, O: Pollution concern river area, F: Industrial area, P: General waste landfill area, I: Designated waste landfill area, K: Metal mine area, B: Area near the manure treatment plant, J: Resident health survey area, U: Amusement park & Park area, G: Golf course area, C: Urban residential area, T: Storage tank area).

Natural radionuclides in plants, soils and sediments affected by U-rich coal mining activities in Brazil

Mining activities can increase the mobility of metals by accelerating the dissolution and leaching of minerals from the rocks and tailing piles to the environment and, consequently, their availability for plants and subsequent transfer to the food chain. The weathering of minerals and the disposal of coal waste in tailing piles can accelerate the generation of acid mine drainage (AMD), which is responsible for the higher dissolution of metals in mining areas. In this context, the behavior of U, Th and K in soils and sediment, and the transfer factor (TF) of 238U, 234U and 210Po for soybean, wheat, pine and eucalyptus cultivated around a coal mine in southern Brazil was evaluated. Alpha and gamma spectrometry were used for the measurements of the activity concentration of the radioelements. 210Po was the radionuclide that is most accumulated in the plants, especially in the leaves. When comparing the plant species, pine showed the highest TF values for 234U (0.311 ± 0.420) for leaves, while eucalyptus showed the highest TF for 238U (0.344 ± 0.414) for leaves. In general, TF were higher for the leaves of soybean and wheat when compared to the grains, and grains of wheat showed higher TF for 210Po and 238U than grains of soybean. Deviations from the natural U isotopic ratio were recorded at all investigated areas, indicating possible industrial and mining sources of U for the vegetables. A safety assessment of transport routes and accumulation of radionuclides in soils with a potential for cultivation is important, mainly in tropical areas contaminated with solid waste and effluents from mines and industry.

Ecological and human health risk assessment of agricultural soils based on heavy metals in mining areas of Singhbhum copper belt, India

ABSTRACTRisk characterization of agricultural soils in the mining areas of Singhbhum copper belt was done by determining the total concentrations of metals using inductively coupled plasma-mass spectrometry and assessing the potential ecological and human health risks. The concentrations were above the average shale values for most of the metals. Principal component analysis showed anthropogenic contributions of Cu, Ni, Co, Mn, Pb, and Cr in the soils. Ecological risk assessment revealed that 50% of the soil samples were at moderate to very high ecological risk. Health risks for adults and children were calculated using hazard quotients (HQs), hazard index (HI), and Cancer risks for the oral, dermal, and inhalation pathways. The HQs for all the metals except As and Co were below 1, which suggested that non-carcinogenic risks due to metal exposure through soils were within the safe limit. However, considering all the metals and pathways, the HI for adults and children was 0.71 and 5.61, respectively, suggesting appreciable risk to local residents. The carcinogenic risks due to As and Cr in the soils were within the acceptable value of 1E–04. For both carcinogenic and non-carcinogenic risks, oral ingestion appeared to be the primary pathway followed by dermal and inhalation pathways.

Heavy metals translocation and accumulation from the rhizosphere soils to the edible parts of the medicinal plant Fengdan (Paeonia ostii) grown on a metal mining area, China

Fengdan (Paeonia ostii) is one of Chinese 34 famous medicinal materials. This study investigated the concentrations of Arsenic (As), Chromium (Cr), Cadmium (Cd), Copper (Cu), Lead (Pb), Iron (Fe), Manganese (Mn), and Zinc (Zn) in rhizosphere soils, cortex mouton and seeds of Fengdan planted in a metal mining area, China. The mean concentrations of As, Cd, Cu, and Zn in the rhizosphere soils were above the limits set by the Chinese Soil Environmental Quality Standard (GB 15618-1995). The contamination factor (CF) of Cd was >5, while it was >2for As, Cu, Pb, and Zn in all the soils. The integrated pollution index for all the soils was >3 and ˂ 5. Metal concentrations in the edible parts of Fengdan were in the following decreasing order: Mn>Fe>Zn>Cu>Pb>As>Cr≥Cd. The transfer factor mean values for As, Cu, Cd and Fe in the cortex moutan of old Fengdan (over 6 years) were significantly higher than in young Fengdan. Available metal concentrations, pH and soil organic matter content influenced the metal concentrations of the cortex moutan. The results indicated that mining and smelting operations have led to heavy metals contamination of soils and medicinal parts of Fengdan. The major metal pollutants were elemental Cd, Cu, Pb, and Zn. Heavy metals mainly accumulated in the cortex moutan of Fengdan. The mean concentrations of Cd, Cu, and Pb in the old cortex moutan (over 6 years) were above those of the Chinese Green Trade Standards for Medicinal Plants and Preparations in Foreign Trade (WM/T2-2004).