Risk assessment and distribution of soil Pb in Guangdong, China

In this study, the spatial distributions of soil lead (Pb) concentration in three horizontal soils in Guangdong, China, were surveyed and analyzed using geostatistics and geography information systems (GIS). Findings indicated that the Pb geometric mean concentration of 23.3 mg/kg in surface soils was found to be higher than those in global soils, which ranged from 2.3–235 mg/kg. In addition, the Pb geometric mean concentrations from A- to C-horizon were found to be 23.3, 27.2, and 28.6 mg/kg, respectively. The classification of a soil Pb environmental risk in an area was likewise presented based on the different levels of environmental quality of Pb and was done by GIS technology. Accordingly, there is a higher local concentration of Pb in the surrounding areas of Guangzhou where there is higher population density and in the north of Guangdong, which is a historic mining area. The results obtained by the environmental risk assessment reveal that about 46% of total surveyed area was above the background value, that is, 2.7% of the total area was at risk of pollution.     

Four trace elements contents of water environment of mining subsidence in the Huainan diggings, China

Mining subsidence pool is the special waters formed by coal mining, located near the mine. We understand the impact on these waters of the surrounding coal production activities and the electricity plant through research the content and characteristics of harmful trace elements in coal contained in these waters. Pb, Hg, Se and Cr these four trace elements increase 0.52, 0.78, 0.70 and 0.28% respectively in Datong mining subsidence pool from November 2004 to November 2006; the four elements increase 1.52, 1.23, 1.08 and 1.08% respectively in Xie'er mining subsidence pool; the four elements increase 1.01, 1.06, 1.02 and 0.83% respectively in Pansan mining subsidence pool. The absolute value of Pb, Hg, Se and Cr in mining subsidence pool is related with their background value, while the increase in their concentration and their environment of mine and electricity plant surrounded are closely linked.     

昌吉硫磺沟矿区地表沉陷区的土地整治与生态恢复

针对昌吉市硫磺沟矿区煤矿开采引起的地表沉陷及其对矿区地表及环境破坏的影响,以减轻地表沉陷危害程度、恢复矿区所在地的生态功能为目标,按照采矿区塌陷类型、塌陷坑大小及塌陷区地理环境,采用不同的土地整治与生态恢复措施,在防治和控制矿区地表沉陷引起的生态破坏及生态环境保护方面取得很好的成果与经验.     

Distribution and contamination assessment of heavy metals in sediment of the Second Songhua River, China

The Second Songhua River was subjected to a large amount of raw or primary effluent from chemical industries in Jilin city in 1960s to 1970s, resulting in serious mercury pollution. However, an understanding of other trace metal pollution has remained unclear. The objective of this study was to investigate trace metal contamination in the sediment of the river. Bottom sediment samples were taken in the river between Jilin city and Haerbin city in 2005. An uncontaminated sediment profile was taken in the Nen River at the same time. Total concentrations of Al, Fe, Mg, Ca, K, Na, Ti, Mn, V, Sc, Co, Cu, Cr, Ni, Pb and Zn in the sediment samples were measured by ICP-MS or ICP-OES, following digestion with various acids. Concentrations of Co, Cu, Cr, Ni, Pb and Zn in the surface sediments were 5.1–14.7, 18.5–78.9, 2.4–75.4, 7.2–29.0, 13.5–124.4, and 21.8–403.1 mg/kg, respectively, generally decreasing along the course of the river from Jilin city to Haerbin city. Background concentrations of trace metals were reconstructed by geochemical normalization to a conservative element scandium. Results showed that concentrations of Co, Cr, and Ni in the sediment were generally only slightly higher than or equal to their background values, while concentrations of Cu, Pb, and Zn in the some sediment samples were significantly higher than their background values. In detail, the sediment at Jilin city was moderately contaminated by Cu, and the sediment of the Second Songhua River was moderately contaminated by Pb and Zn. The top layer (0–10 cm depth) and bottom layers (30–46 cm depth) of one sediment profile at Wukeshu town were generally moderately polluted by Pb and Zn. Synthetically, the surface sediment in the studied river section was classified as natural sediment without ecological risk by the sediment pollution index (SPI) of Cu, Cr, Ni, Pb and Zn. Only the 30–45 cm depth of the sediment profile at Wukeshu town was classified as low polluted sediment by the SPI of these metals, recording a historical contamination of the river in the 1960s to 1970s. This buried contamination of trace metals might pose a potential risk to water column under disturbance of sediment. Foundation item: The National Basic Research Priorities Program of China (2004CB418502)     

Characteristics of Hazardous Airborne Dust Around an Indian Surface Coal Mining Area

Surface coal mining creates more air pollution problems with respect to dust than underground mining . An investigation was conducted to evaluate the characteristics of the airborne dust created by surface coal mining in the Jharia Coalfield. Work zone air quality monitoring was conducted at six locations, and ambient air quality monitoring was conducted at five locations, for a period of 1 year. Total suspended particulate matter (TSP) concentration was found to be as high as 3,723 μg/m³, respirable particulate matter (PM10) 780 μg/m³, and benzene soluble matter was up to 32% in TSP in work zone air. In ambient air, the average maximum level of TSP was 837 μg/m³, PM10 170 μg/m³ and benzene soluble matter was up to 30%. Particle size analysis of TSP revealed that they were more respirable in nature and the median diameter was around 20 μm. Work zone air was found to have higher levels of TSP, PM10 and benzene soluble materials than ambient air. Variations in weight percentages for different size particles are discussed on the basis of mining activities. Anionic concentration in TSP was also determined. This paper concludes that more stringent air quality standards should be adopted for coal mining areas and due consideration should be given on particle size distribution of the air-borne dust while designing control equipment.     

Health risk assessment of fluoride in drinking water from Anhui Province in China

This study analyzes the concentrations and health risks of fluoride in 249 drinking water samples collected from different regions of Anhui Province in China. Results indicated that fluoride content in drinking water ranged from 0.12 to 1.94 mg L^?1 (mean?=?0.57 mg L^?1) in the following order: Huaibei plain region > Jianghuai hill region ≈ Dabieshan mountainous region > plain along the Yangtze River region > southern Anhui mountainous region. The fluoride contents were less than 0.50 mg L^?1 in 66.66 % of the drinking water samples, 0.51–1.0 mg L^?1 in 23.29 %, and higher than 1.0 mg L^?1 in 12.04 %. The fluoride levels in some samples were lower than the recommended values for controlling dental caries (0.50–1.0 mg L^?1). The total fluoride intake from drinking water was between 0.14 and 2.33 mg per day in different regions of the province, supposing an individual consumes 1.2 L of water per day. Therefore, measures should be taken to increase fluoride intake in the Jianghuai hill region, Dabieshan mountainous region, plain along the Yangtze River, and southern Anhui mountainous region to control dental caries. On the other hand, the fluoride levels must be reduced in the Huaibei plain region to decrease endemic fluorosis. The results serve as crucial guidelines for managing fluoride safety in drinking water and controlling endemic fluorosis in different regions of Anhui Province.     

Comparative on Causes and Accumulation of Selenium in the Tree-rings Ambient High-selenium Coal Combustion Area from Yutangba, Hubei, China

Toxic trace elements emitted during coal combustion are the main sources of air pollution. They are released into the atmosphere mainly in the forms of fine ash, smoke and flue, and thus adversely affect plant, animal and human health. Selenium is one of toxic and the most volatile in coal. Large amount of atmospheric emission of selenium, as well as selenium present and scrubber stockpiles in ash may create serious environmental problems. In the paper, on the basis of investigating the abundance and distribution of selenium in plant-rings during recent 20 years, the bioaccumulation of selenium is explained that selenium in plant, which were collected from the village of selenium-rich coal combustion, is much higher than that in plants collected away from the village of selenium-rich coal combustion. The main origins of selenium are selenium-rich coal combustion and high-selenium rock weathered. The selenium recycle by food chain and selenium will accumulate and redistribute in environments.     

Distribution,sources, and ecological risk assessment of SVOCs in surface sediments from Guan River Estuary,China

The contamination of semi-volatile organic compounds (SVOCs) in the surface sediments of the Guan River Estuary, China was fully investigated. Total concentrations of 56 species of SVOCs ranged from 132 to 274 ng/g with an average of 186 ng/g (dry weight). Polycyclic aromatic hydrocarbon (PAH) concentrations were positively correlated with clay content and negatively correlated with sediment grain size. Source identification indicated that PAHs originated mainly from pyrolytic sources. However, intense ship traffic in the estuary may provide sources of petrogenic PAHs. Organochlorine pesticides (OCPs) mainly originated from direct input of dichlorodiphenyltrichloroethanes (DDTs) during some industrial processes. The SVOC concentrations were also compared with International Sediments Quality Guidelines and Sediments Quality Criteria, and the results indicated that negative biological impacts may originate from high concentrations of FLO, p,p′-DDE, and total DDTs.     

Distribution of HCH and DDT in the coastal marine environment of Mumbai,India

Organochlorine pesticides (OCPs) in sediment, water and biota samples from the coastal marine environment of Mumbai were analysed to elucidate their distribution in various environmental compartments. HCH isomers, dichlorodiphenyltrichloroethane (DDT) and its metabolites were the predominantly identified compounds in all the samples. High ratios of DDT to dichlorodiphenyldichloroethylene (DDE) were found in seawater samples. This indicates the presence of a significant source of DDT in this region. In sediment samples, the gamma-isomer contributed almost 55% to the total HCH, indicating a high affinity of the gamma-isomer towards the sediment. The levels of organochlorines in fish obtained from this region were found to be lower than the levels of organochlorines in fish in temperate regions.     

Distribution, speciation, and risk assessment of selected metals in the gold and iron mine soils of the catchment area of Miyun Reservoir, Beijing, China

In order to investigate the metal distribution, speciation, correlation and origin, risk assessment, 86 surface soil samples from the catchment area around the Miyun Reservoir, Beijing, including samples from gold and iron mine areas, were monitored for fractions of heavy metal and total contents. Most of the metal concentrations in the gold and iron mine soil samples exceeded the metal background levels in Beijing. The contents of most elements in the gold mine tailings were noticeably higher than those in the iron mine tailings. Geochemical speciation data of the metals showed that the residual fraction dominated most of the heavy metals in both mines. In both mine areas, Mn had the greatest the acid-soluble fraction (F1) per portion. The high secondary-phase fraction portion of Cd in gold mine samples indicated that there was a direct potential hazard to organisms in the tested areas. Multivariate analysis coupled with the contents of selected metals, showed that Hg, Pb, Cr, and Ni in gold mine areas represented anthropogenic sources; Cd, Pb, and Cr in iron mine areas represented industrial sources. There was moderate to high contamination of a few metals in the gold and iron soil samples, the contamination levels were relatively higher in gold mine than in iron mine soils.     

Distribution,sources, and toxicity assessment of polycyclic aromatic hydrocarbons in surface soils of a heavy industrial city,Liuzhou, China

As a heavy industrial city, Liuzhou has been facing a serious pollution problem. It is necessary to take steps to control and prevent environmental pollution wherever possible. Surface soil samples were collected from four communities in Liuzhou City, to determine the concentrations, distributions, sources, and toxicity potential of polycyclic aromatic hydrocarbons (PAHs) present. The mean concentrations of total PAHs in the surface soil are 756.43 ng/g for the heavy industrial area, 605.06 ng/g for the industrial area, 481.24 ng/g for the commercial–cum–residential area, and 49.93 ng/g for the rural area. Both the isomer ratio and principal component analyses for the PAHs prove that these pollutants originate mainly from coal, diesel, gasoline, and natural gas combustion. The pollution hierarchies and toxic equivalency factor of BaP prove that the city is subject to heavy pollution caused by industry, transportation, and daily human activities.     

Generation and Quantification of Hazardous Dusts from Coal Mining in the Indian Context

The increasing trend of opencast coal mining in India tends to release huge amounts of dust. But there is no well-defined method of estimating dust emission due to different coal mining activities. This paper examines the sources of dust emission due to coal mining activities, and focuses on the quantification of dust emission with the development and use of emission factors. Because of their site-specific nature, emission factors developed for one site may not give the correct results for another site. In the present investigation, prediction equations are utilized for the development of emission factors. For the applications of this concept, one large opencast coal project of Bharat Coking Coal Ltd. (BCCL) was investigated, and the total amount of dust emitted due to different mining activities was calculated by the utilization of emission factor data, which was estimated to be 9368.2 kg/day. This paper also focuses on the significance of this study in the field of environmental protection and likely impacts of such study. The paper concludes that once the amount of dust generation is estimated, the impact on air quality can be assessed appropriately and a proper air-pollution control strategy can be developed.     

Spatial distribution and multiple sources of heavy metals in the water of Chaohu Lake,Anhui, China

In this study, a survey for the spatial distribution of heavy metals in Chaohu Lake of China was conducted. Sixty-two surface water samples were collected from entire lake including three of its main river entrances. This is the first systematic report concerning the content, distribution, and origin of heavy metals (Cu, Cr, Cd, Hg, Zn, and Ni) in the Chaohu Lake water. The results showed that heavy metals (Cu, Cr, Zn, and Ni) concentrations in the estuary of Nanfei River were relatively higher than those in the other areas, while content of Hg is higher in the southeast lake than northwest lake. Moreover, Cd has locally concentration in the surface water from the entire Chaohu Lake. The heavy metal average concentrations, except Hg, were lower than the cutoff values for the first-grade water quality (China Environment Quality Standard) which was set as the highest standard to protect the social nature reserves. The Hg content is between the grades three and four water quality, and other heavy metals contents are higher than background values. The aquatic environment of Chaohu Lake has apparently been contaminated. Both the cluster analysis (CA) and correlation analysis provide information about the origin of heavy metals in the Lake. Our findings indicated that agricultural activities and adjacent plants chimneys may contribute the most to Cd and Hg contamination of Chaohu Lake, respectively.     

Distribution,bioavailability, and potential ecological risk of Cu,Pb, and Zn in soil in a potential groundwater source area

In this study, we examined three horizontal and vertical soil profiles along a sewage drainage ditch in order to determine the spatial distribution of Cu, Pb, and Zn in soils and to assess the bioavailability and potential ecological risks associated with these metals in a potential groundwater source area. Results showed that the concentrations of Cu, Pb, and Zn were approximately at background level, suggesting that human activities (industrial and agricultural pollution) had a negligible influence on these metals in soil, and that the concentrations reflected the natural background levels in the study area. Cu, Pb, and Zn concentrations were slightly higher in topsoil (0–20 cm) than deeper in the soil profile. Using a modified BCR sequential extraction method to evaluate the mobility and bioavailability of metals showed that the potential bioavailability sequence of Cu, Pb, and Zn at three depths in the soil profile was in the order Cu?≈?Pb?<?Zn. The potential ecological risk from the metals was evaluated using risk assessment code, and the results suggest that Cu and Zn pose no or low risk, while there is a low or medium risk from Pb. Results from groundwater monitoring showed that the groundwater was not polluted by leaching from soil.     

对新疆某铀伴生煤矿辐射环境影响分析及污染防治探讨

通过对新疆某煤矿辐射环境影响问题的调查与分析,阐明铀伴生煤矿对周围环境存在着不同程度的放射性影响,并在调查与分析的基础上,针对调查煤矿日前存在的问题提出了一些污染防治的对策和措施,以期为今后伴生放射性煤矿的环境管理决策提供有力依据。     

Distribution of PAEs in the middle and lower reaches of the Yellow River, China

Samples of water, sediment and suspended particulates were collected from 13 sites in the middle and lower reaches of the Yellow River in China. Phthalic acid esters (PAEs) concentrations in different phases of each sample were determined by Gas Chromatogram GC-FID. The results are shown as follows: (1) In the Xiao Langdi–Dongming Bridge section, PAEs concentrations in water phase from the main river ranged from 3.99 × 10⁻³ to 45.45 × 10⁻³ mg/L, which were similar to those from other rivers in the world. The PAEs levels in the tributaries of the Yellow River were much higher than those of the main river. (2) In the studied branches, the concentration of PAEs in sediment for Luoyang Petrochemical Channel (331.70 mg/Kg) was the highest. The concentrations of PAEs in sediment phase of the main river were 30.52 to 85.16 mg/Kg, which were much higher than those from other rivers in the world. In the main river, the concentration level of PAEs on suspended solid phases reached 94.22 mg/Kg, and it reached 691.23 mg/Kg in the Yiluo River – one tributary of the Yellow River. (3) Whether in the sediment or on the suspended solid phases, there was no significant correlation between the contents of PAEs and TOC or particle size of the solid phase; and the calculated Koc of Di (2-Ethylhexyl) Phthalate (DEHP) in the river were much less than the theoretical value, which inferred that PAEs were not on the equilibrium between water and suspended solid phases/sediment. (4) Among the measured PAEs compounds, the proportions of DEHP and di-n-butyl phthalate (DBP) were much higher than the others. The concentrations of DEHP exceeded the Quality Standard in all the main river and tributary stations except those in the Mengjin and Jiaogong Bridge of the main river. This indicates that more attention should be paid to pollution control and further assessment in understanding risks associated with human health.     

镇江地区土壤中重金属Cu和Pb污染状况与空间分布

为了锯镇江地区土壤中重金属Cu和Ph的污染状况与空间分布,对镇江地区表层土壤中的Cu和Pb进行了采样监测。结果表明,镇江地区表层土壤中cu的含量为19．2～273mg／kg,Pb的含量为20．6～3846mg／kg。与全省土壤背景值相比,均有一定程度的富集。对cu和Pb的相互关系进行分析可得出,镇江地区土壤在一定程度上受到农业面源的污染。     

Effect of heavy metals (Cu, Pb, and As) on the ultrastructure of Sargassum pallidum in Daya Bay, China

Concentrations of Cu, Pb, and As were determined in seawater, surface sediment, Sargassum pallidum collected from the Daya Bay, China. The influence of metal contamination on the marine alga was investigated at chemical and ultrastructural level. Mean concentrations of Cu (19.44 mg kg^?1) and Pb (33.99 mg kg^?1) were found to be high in sediment, whereas concentration of As (122.29 mg kg^?1) in S. pallidum was higher than that in water and sediment. The ultrastructure of S. pallidum cells was anomalous and aberrant. Energy-dispersive x-ray spectroscopic analysis revealed that the nanometal particles in the form of comparatively high-electron density substance diffused in the cell structures constituted by Cu, Pb, As, etc. There is a remarkable similarity or correspondence in the anomalous elements between the geochemistry and the botanic cell, and the heavy metals have potential hazardous effect on the ocean ecology system in Daya Bay.