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1.
An investigation on spatial distribution, possible pollution sources, and affecting factors of heavy metals in the urban–suburban soils of Lishui city (China) was conducted using geographic information system (GIS) technique and multivariate statistics. The results indicated that the topsoils in urban and suburban areas were enriched with metals, such as Cd, Cu, Pb, and Zn. Spatial distribution maps of heavy metal contents, based on geostatistical analysis and GIS mapping, indicated that Cd, Cr, Cu, Mn, Ni, Pb, and Zn had similar patterns of spatial distribution. Their hot-spot areas were mainly concentrated in the densely populated old urban area of the city. Multivariate statistical analysis (correlation analysis, principal component analysis, and clustering analysis) showed distinctly different associations among the studied metals, suggesting that Cr, Cu, Ni, Pb, Cd, and Zn had anthropogenic sources, whereas Co and V were associated with parent materials and therefore had natural sources. The Cd, Cr, Ni, Pb, and Zn contents were positively correlated with soil organic matter, pH, and sand content (p < 0.01). It is concluded that GIS and multivariate statistical methods can be used to identify hot-spot areas and potential sources of heavy metals, and assess soil environment quality in urban–suburban areas.  相似文献   

2.
某矿区土壤重金属分布特征及来源解析   总被引：1，自引：0，他引：1  
为探究赣南某矿区土壤重金属污染状况及来源,以该矿区内40个土壤样品为研究对象,分析了土壤中Cu、Pb、Zn、Cr、Ni、Cd、As和Hg等8种重金属元素的含量,并采用频率直方图、相关性分析、主成分分析等多种统计方法探究了土壤重金属含量的分布特征及来源。研究结果表明:(1)研究区8种重金属中有7种不同程度地超过了江西省土壤重金属元素背景值;(2)Pb、Zn、As和Hg的含量接近正态分布,而Cu、Cr、Ni和Cd的含量则呈现出右偏分布的趋势,这可能与研究区矿山开采活动及土地利用类型等因素有关;(3)矿区土壤重金属相关性分析表明,Cu、Cr、Ni的同源性较高,可能具有相同的污染源,而Pb、Zn、Cd等元素与Cu、Cr、Ni相比,其来源可能存在一定的差异;(4)主成分分析结果显示,矿区内土壤中8种重金属元素含量可以由2个主成分来解释,所代表的实际意义按贡献率排序分别是成土母质和人为采矿活动;(5)矿区内土壤重金属污染物主要为Pb、Zn、Cd,人为采矿活动是这三种重金属污染的主要来源。  相似文献   

3.
固体聚合膜电解浓集法是浓缩氚含量较低(1 Bq/m~3)的天然水样的常用方法,但因水样自身含有杂质离子或电解装置聚合膜带入杂质进入浓集液,使浓集液偏酸性,在测量过程中易产生化学淬灭效应,导致氚的测量值偏低。本文研究了水样自身存在的杂质离子和聚合膜上残留的杂质离子、样品溶液的pH值及其电导率所产生的化学淬灭效应的影响,实验表明,为减少化学淬灭效应,提高测量低含量氚的准确性,需保证水样溶液呈中性,电导率≤1μS/cm,同时避免杂质沉积在聚合膜上。如果水样溶液的pH值偏酸性、电导率大于1μS/cm,可采用酸碱混合型离子交换树脂去除水样中自身的杂质;对于聚合膜引入的杂质,可在电解后的水样中加入微量氨水将其pH值调节至中性。  相似文献   

4.
Urban roadside soils are the “recipients” of large amounts of heavy metals from a variety of sources including vehicle emissions, coal burning waste and other activities. The behavior of heavy metals in urban roadside soils depends on the occurrence as well as the total amount. Accordingly, knowledge of the interactions between heavy metals and other constituents in the soil is required to judge their environmental impact. In this study, correlations of heavy metal concentrations (Pb, Zn, Cu, Ag, Se, Ni, Cr and Ba) to iron extracted using dithionite–citrate–bicarbonate (DCB) buffer (FeDCB), fulvic acids and particle size fractions were examined from the Xuzhou urban roadside soils. Heavy metals except for Cr and fulvic acids had a positive significant correlation with FeDCB, indicating these metals and fulvic acids are principally associated with the surfaces of iron oxides of the soils. Significant positive correlations were also found between the contents of fulvic acids and heavy metals, showing these heavy metals (especially for Cu, Ni and Cr) form stable complexes with fulvic acids. Such finding is of importance with regard to the increased mobilization of heavy metals, e.g., into freshwater ecosystems. Ag, Se and Cr are independent of particle size fractions because of their low concentrations of Ag and Se in the studied soils. Pb, Zn, Cu, Ba and Ag are mainly enriched in the finer soil particles (especially <16 μm).  相似文献   

5.
Levels of heavy metals are found in soils and waters of the major tributary valleys of the Jordan Valley. Heavy metal content in soils irrigated by treated waste water were measured for a 40 km reach of Zarqa River. Soil samples from eight different sites along the upper course of this river were analyzed to determine the concentration of selected heavy metals (CO, Cr, Cu, Pb, Ni, Zn). Silt forms the major component of the soils with an average of 54%. Clay fractions show an increase with depth from 17 to 41%. Trends in particle size distribution and metal contents were compared across sample sites. Samples contained moderate to considerable levels of Pb and Ni. Concentrations of Cu and Cr ranged between 33–59 and 65–90 ppm, respectively. These values represent a slight to moderate class of pollution. The concentration of Cr shows a decrease with depth and distance from the waste water plant. Cu, Zn, and Ni show increasing concentrations with depth but Pb and CO do not. The concentrations of the measured heavy metals increases near the waste water treatment plant but decreases with distance from the plant due to precipitation in the stream bed and dilution with stream water. This decline in metal content with distance from the treatment plant suggests that most metals reaching floodplain soils may derive from the same source. Although current metal concentrations are low to moderate, floodplain surface soils in this area should be regarded as a potential source for future heavy metal pollution downstream.  相似文献   

6.
为了解包头市典型工业企业对其所在地土壤中重金属含量的影响及污染现状,利用相关性系数对其表层土壤中7种重金属(Cu、Zn、Pb、Cr、Cd、Mn、Ni)来源进行研究,并采用内梅罗综合污染指数法和潜在生态危害指数对其污染状况进行评价。结果表明,7种重金属含量平均值均高于内蒙古土壤背景值,其中Cd、Mn、Ni超标率已达100%,而Cu、Pb、Zn的超标率分别为97%、93%和93%,只有Cr超标率较低(53%),污染程度依次为CdPbCuNiZnMnCr,其中Pb和Cd为重度污染,Cu、Zn、Ni为中度污染,Cr、Mn为轻度污染;Cu、Zn、Cr、Mn、Ni可能同时来自工业生产和交通运输两个源,而Pb和Cd除上述来源外,燃煤烟气的排放有较大贡献。潜在生态危害依次为CdPbCuNiCrZnMn,其中Cd的潜在生态风险最大,应予以高度重视,其他金属的风险均为轻微。  相似文献   

7.
Urban roadside soils are important environmental media for assessing heavy metal concentrations in urban environment. However, among other things, heavy metal concentrations are controlled by soil particle grain size fractions. In this study, two roadside sites were chosen within the city of Xuzhou (China) to reflect differences in land use. Bulk soil samples were collected and then divided by particle diameter into five physical size fractions, 500–250, 250–125, 125–74, 74–45, < 45 μm. Concentrations of metals (Ti, Cr, Al, Ga, Pb, Ba, Cd, Co, Cu, Mn, Ni, V, Zn, Mo, As, Sb, Se, Hg, Bi, Ag) were determined for each individual fraction. These metals could be roughly classified into two groups: anthropogenic element (Pb, Ba, Cd, Cu, Zn, Mo, As, Sb, Se, Hg, Bi, Ag) and lithophile element (Ti, Cr, Al, Ga, Co, Mn, Ni, V) in terms of values of enrichment factor. As expected, higher concentrations of anthropogenic heavy metals (Cu, Zn, Mo, As, Hg, Bi, Ag) are observed in the finest particle grain size fraction (i.e. < 45 μm). However, heavy metals Se, Sb and Ba behave independently of selected grain size fractions. From the viewpoint of mass loading, more than 30% of the concentrations for all anthropogenic heavy metals are contributed by the particle grain size fractions of 45–74 μm at site 1 and more than 70% of the concentrations for all heavy metals are contributed by the particle grain size fractions of 45–74 and 74–125 μm at site 2. These results are important for transport of soil-bound heavy metals and pollution control by various remedial options.  相似文献   

8.
The concentration of heavy metals such as Ba, Co, Cr, Cu, Ni, Pb, Rb, Sr, V, Y, Zn, Zr were studied in soils of Balanagar industrial area, Hyderabad to understand heavy metal contamination due to industrialization and urbanization. This area is affected by the industrial activities like steel, petrochemicals, automobiles, refineries, and battery manufacturing generating hazardous wastes. The assessment of the contamination of the soils was based on the geoaccumulation index, enrichment factor (EF), contamination factor, and degree of contamination. Soil samples were collected from Balanagar industrial area from top 10–50 cm layer of soil. The samples were analyzed using X-ray fluorescence spectrometer for heavy metals. The data revealed that the soils in the study area are significantly contaminated, showing high level of toxic elements than normal distribution. The ranges of concentration of Cr (82.2–2,264 mg/kg), Cu (31.3–1,040 mg/kg), Ni (34.3–289.4 mg/kg), Pb (57.5–1,274 mg/kg), Zn (67.5–5819.5 mg/kg), Co (8.6–54.8 mg/kg), and V (66.6–297 mg/kg). The concentration of above-mentioned other elements was similar to the levels in the earth’s crust pointed to metal depletion in the soil as the EF was <1. Some heavy metals showed high EF in the soil samples indicating that there is a considerable heavy metal pollution, which could be correlated with the industries in the area. A contamination site poses significant environmental hazards for terrestrial and aquatic ecosystems. They are important sources of pollution and may results in ecotoxicological effects on terrestrial, groundwater and aquatic ecosystems.  相似文献   

9.
The capital city of Botswana, Gaborone, has seen unprecedented population, economic, and industrial growth in recent years. In order to assess how this rapid urbanisation process impacts the environment, 106 silt and clay (particle size <0.053 mm) samples, separated from Gaborone surface soil samples representing urban, agricultural and rural sites, were investigated. The concentrations of nine heavy metals (Sc, Cr, Co, Ni, Cu, Zn, Nb, Cd, and Pb) were measured using ICP–MS and GFAAS, and the resulting patterns were correlated to the bedrock composition and anthropogenic activities. As expected, we found that samples from soils on top of dolerites show higher levels of Cr, Ni, and Cu than those on top of granites and rhyolites. However, our studies also show that Gaborone city centre soils are moderately polluted by Pb (up to 222 mg/kg, i.e. 5.7-fold the concentration in comparable rural soils), as a result of heavy traffic. Furthermore, Cr and Ni pollution originating from agrochemicals were shown to be accumulating in Gaborone crop soils. Our studies also showed moderate levels of Zn pollution and low level, dot-shaped pollution of Cr, Co, Ni, Cu detected in Gaborone residential and industrial soils that are correlated to waste disposal. Interestingly, the highest levels of Sc, Cr, Co, Ni and Zn pollution are found near two abandoned sewage works. The results of sequential extraction indicate that the polluting Co and Ni exist in all speciations; the polluting Cu mainly exists in the residue of the sequential extraction, whereas the polluting Pb is mostly bound to organic matters and Fe- and Mn-oxides. These results highlight the need for instituting a systematic and continuous monitoring of heavy metals and other forms of pollutants in Gaborone to ensure that pollution does not become a serious problem in the future.  相似文献   

10.
Mapping soil pollution by spatial analysis and fuzzy classification   总被引：1，自引：0，他引：1  
Spatial analysis and fuzzy classification techniques were used to estimate the spatial distributions of heavy metals in soil. The work was applied to soils in a coastal region that is characterized by intense urban occupation and large numbers of different industries. Concentrations of heavy metals were determined using geostatistical techniques and classes of risk were defined using fuzzy classification. The resulting prediction mappings identify the locations of high concentrations of Pb, Zn, Ni, and Cu in topsoils of the study area. The maps show that areas of high pollution of Ni and Cu are located at the northeast, where there is a predominance of industrial and agricultural activities; Pb and Zn also occur in high concentrations in the northeast, but the maps also show significant concentrations of Pb and Zn in other areas, mainly in the central and southeastern parts, where there are urban leisure activities and trade centers. Maps were also prepared showing levels of pollution risk. These maps show that (1) Cu presents a large pollution risk in the north–northwest, midwest, and southeast sectors, (2) Pb represents a moderate risk in most areas, (3) Zn generally exhibits low risk, and (4) Ni represents either low risk or no risk in the studied area. This study shows that combining geostatistics with fuzzy theory can provide results that offer insight into risk assessment for environmental pollution.  相似文献   

11.
Detailed magnetic and geochemical measurements were performed on urban roadside soils collected from Lishui city, China, to establish a possible link between the enhanced concentration of traffic-related magnetic particles and heavy metals. Relatively higher magnetic susceptibility (mean: 124.1 × 10−8 m3 kg−1) and concentrations of metals (Cd, Cu, Pb and Zn) were observed for roadside soils. Concentration-dependent magnetic parameters (χ and SIRM) are highly significantly positively correlated to the concentration of metals (Ca, Cr, Ni, Cu, Zn, Cd, Pb, Fe, and V), but not significantly correlated with As, Mn, Co, Mg, and K. The principal component analysis showed that χ and SIRM significantly correspond to elements Ca, Cd, Cu, Pb, and Zn. The χ and SIRM also have significant linear correlation with integrated pollution index, indicating that χ and SIRM can be used as effective proxy indicators for the pollution of heavy metals. Magnetite in the pseudo-single-domain/multidomain (PSD/MD) grain size was identified as the dominant magnetic carrier by temperature-dependent measurements of saturation magnetization (Ms–T curve), XRD and hysteresis loops. Field emission scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS) analysis of the magnetic particles revealed the presence of large traffic-related angular-subangular, blocky, and spherical iron oxide particles. These iron oxide particles are typical for particles produced by traffic-related anthropogenic activities. It is concluded that vehicle emissions may be the major source of elevated heavy metals and magnetic particles in roadside soils. The results proved the applicability of magnetic method in detecting roadside pollution derived from vehicle emissions.  相似文献   

12.
王图锦  潘瑾  刘雪莲 《岩矿测试》2016,35(4):425-432
消落带是水域与陆地的过渡地带,对水环境有着至关重要的影响。本文以三峡库区消落带面积最大的澎溪河流域作为研究区域,采集消落带土壤及其沿岸土壤样品,分析重金属形态分布特征,并使用地质累积指数法和风险评价准则(RAC)对重金属污染程度及生态风险进行评价。研究表明,消落带土壤中Pb、Cu、Cr、Cd、Zn和Ni平均含量分别为68.70、36.96、55.10、0.68、108.26、31.68 mg/kg,污染程度依次为CdPbZnCuNiCr,以Cd和Pb污染较为突出,普遍高于长江干流土壤,远高于重庆地区土壤。Cd的RAC值为20.62%,呈中等环境风险;其形态稳定性最差,以可还原态和酸提取态为主。Pb、Cu、Cr、Zn、Ni的RAC值为5.45%~10.0%,环境风险较低;且均以残渣态为主,占总量的54.69%~83.05%。以消落带沿岸土壤为对照,消落带形成后土壤中各重金属总量均有不同程度升高,且不同重金属在其增量部分的形态存在差异,Cr和Ni的增量部分以残渣态为主,Cd、Pb、Zn的增量以非残渣态为主。研究发现,由于受到水域与陆地污染源的双重影响,澎溪河流域重金属具有由沿岸向消落带沉积富集的趋势。  相似文献   

13.
Soil pollution in agricultural areas surrounding big cities is a major environmental problem. Tabriz is the largest city in the northwest of Iran and the fourth largest city in the country. Soil samples were taken from 46 sites in the suburbs of the Tabriz city, and separate samples were taken from control site and analyzed. The results indicated that the mean pH value of the soil samples was 9.29, while the mean EC value was 354.33 μs/cm and the amount of TOC and TOM was 0.99 and 1.7 %, respectively. The mean concentrations of Cd, Pb, Cu, Cr, Ni, and Zn in the soil were determined to be 1.61, 10.56, 101.25, 87.40, 38.73, and 98.27 mg/kg, respectively (dry weight). The concentrations of heavy metals (Cd, Pb, Cu, Cr, and Zn), with the exception of Ni, were higher than the concentrations of the same heavy metals at the control site. Despite these elevated concentrations, the concentrations of heavy metals were lower than the toxicity threshold limit of agricultural soils. The values of the pollution index revealed that the metal pollution level was Pb > Cr > Cu > Zn > Cd > Ni, and the mean value of the integrated pollution index was determined to be 1.81, indicating moderate pollution. Nevertheless, there were some sites that were severely polluted by Cr (maximum values of 1,364 mg/kg). It was concluded that city probably has affected the surrounding agricultural area. Application of wastewater (municipal and industrial) as irrigation water, using of sludge as soil fertilizer, and atmospheric perceptions have been considered as main reasons of increased heavy metals concentrations found in the studied area.  相似文献   

14.
Dongguan (东莞) City, located in the Pearl River Delta, South China, is famous for its rapid industrialization in the past 30 years. A total of 90 topsoil samples have been collected from agricultural fields, including vegetable and orchard soils in the city, and eight heavy metals (As, Cu, Cd,Cr, Hg, Ni, Pb, and Zn) and other items (pH values and organic matter) have been analyzed, to evaluate the influence of anthropie activities on the environmental quality of agricultural soils and to identify the spatial distribution of trace elements and possible sources of trace elements. The elements Hg, Pb, and Cd have accumulated remarkably here, incomparison with the soil background content of elements in Guangdong (广东) Province. Pollution is more serious in the western plain and the central region, which are heavily distributed with industries and rivers. Multivariate and geostatistical methods have been applied to differentiate the influences of natural processes and human activities on the pollution of heavy metals in topsoils in the study area. The results of cluster analysis (CA) and factor analysis (FA) show that Ni, Cr, Cu, Zn, and As are grouped in factor F1,Pb in F2, and Cd and Hg in F3, respectively. The spatial pattern of the three factors may be well demonstrated by geostatistical analysis. It is shown that the first factor could be considered as a natural source controlled by parent rocks. The second factor could be referred to as "industrial and traffic pollution sources". The source of the third factor is mainly controlled by long-term anthropic activities ,ad a consequence of agricultural fossil fuel consumption and atmospheric deposition.  相似文献   

15.
 The Yamuna River sediments, collected from Delhi and Agra urban centres, were analysed for concentration and distribution of nine heavy metals by means of atomic adsorption spectrometry. Total metal contents varied in the following ranges (in mg/kg): Cr (157–817), Mn (515–1015), Fe (28,700–45,300), Co(11.7–28.4), Ni (40–538), Cu (40–1204), Zn (107–1974), Pb (22–856) and Cd (0.50–114.8). The degree of metal enrichment was compared with the average shale concentration and shows exceptionally high values for Cr, Ni, Cu, Zn, Pb and Cd in both urban centres. In the total heavy metal concentration, anthropogenic input contains 70% Cr, 74% Cu, 59% Zn, 46% Pb, 90% Cd in Delhi and 61% Cr, 23% Ni, 71% Cu, 72% Zn, 63% Pb, 94% Cd in Agra. A significant correlation was observed between increasing Cr, Ni, Zn, and Cu concentrations with increasing total sediment carbon and total sediment sulfur content. Based on the Müller's geoaccumulation index, the quality of the river sediments can be regarded as being moderately polluted to very highly polluted with Cr, Ni, Cu, Zn, Pb and Cd in the Delhi and Agra urban centres. The present sediment analysis, therefore, plays an important role in environmental measures for the Yamuna River and the planning of these city centres. Received: 21 June 1999 · Accepted: 1 October 1999  相似文献   

16.
对乐安江流域稻田表层土壤中Pb、Cd、Cu、Zn的分布特征进行分析,按照单因子污染指数法和内梅罗综合污染指数法,依据土壤环境背景值标准和国家土壤环境质量标准对乐安江流域稻田土壤的重金属进行评价。结果表明,矿集区上游水稻田土壤重金属综合污染指数等级尚在安全范围内,矿集区周边Cd和Cu的单项污染指数大于1,综合污染指数达到7.82,属于重污染;矿集区下游接近警戒值。研究表明,矿集区矿业开发释放的重金属元素对乐安江中下游流域水稻田土壤的重金属累积具有重要影响。  相似文献   

17.
内江市双桥乡土壤重金属含量及风险评价   总被引：3，自引：0，他引：3  
黄蕾  王鹃  彭培好  王珏玮 《物探化探计算技术》2011,33(4):450-454,349,350
以四川省内江市双桥乡为研究区域,调查分析各类土壤中重金属（Cu、Pb、Zn、Cd、Cr、As、Hg、Ni）含量情况。采用单因子污染指数、内梅罗综合污染指数和富集因子评价方法,对土壤重金属污染状况进行评价。研究结果表明,该地区Cd、Cr、Cu、Ni、Pb、Zn元素平均含量高于成都经济区、四川省、中国土壤背景值,有一定程度的Cd、Cr、Cu、Ni、Pb、Zn富集,Hg元素有个别样点含量偏高,并且单因子重金属的污染程度依次为：Cd〉Ni〉Zn〉Cu〉Cr〉Pb〉As〉Hg,Cd在绝大部份区域存在轻微污染,由内梅罗污染指数和富集因子评价得出区域综合污染程度为轻度。  相似文献   

18.
A study of agricultural lands around an abandoned Pb–Zn mine in a karst region was undertaken to (1) assess the distribution of heavy metals in the agricultural environment, in both dry land and paddy field; (2) discriminate between natural and anthropogenic contributions; and (3) identify possible sources of any pollution discovered. Ninety-two samples of cultivated soils were collected around the mine and analyzed for eight heavy metals, pH, fluoride (F?), cation exchange capacity, organic matter, and grain size. The eight heavy metals included Cd, Cr, Cu, Ni, Pb, Zn, As, and Hg. The average concentrations (mg/kg) obtained were as follows: Cd 16.76 ± 24.49, Cr 151.5 ± 18.24, Cu 54.28 ± 18.99, Ni 57.5 ± 14.43, Pb 2,576.2 ± 1,096, Zn 548.7 ± 4,112, As 29.1 ± 6.36, and Hg 1.586 ± 1.46. In a site where no impact from mining activities was detected, the mean and median of Cd, Cu, Ni, Pb, Zn, As, and Hg concentrations in investigated topsoils were higher than the mean and median of heavy metal concentrations in reference soils. An ensemble of basic and multivariate statistical analyses was performed to reduce the multidimensional space of variables and samples. Two main sets of heavy metals were revealed as indicators of natural and anthropogenic influences. The results of principal component analysis (PCA) and categorical PCA demonstrated that Cd, Cu, Pb, Zn, and Hg are indicators of anthropogenic pollution, whereas Cr, As and Ni concentrations are mainly associated with natural sources in the environment. The contamination from Pb–Zn mining operations, coupled with the special karst environment, was a key contributing factor to the spatial distribution of the eight heavy metals in the surrounding soil. The values of heavy metals in the soil samples suggested the necessity of conducting a rigorous assessment of the health and environmental risks posed by these residues and taking suitable remedial action as necessary.  相似文献   

19.
The contents of Co, Cr, Cu, Mn, Ni, Pb and Zn in the dust samples collected from Changqing industrial park of Baoji city, NW China, were measured by XRF, while As and Hg in the dust samples were analyzed by AFS. Geo-accumulation index (I geo), pollution index (PI) and integrated pollution index (IPI) were calculated to evaluate the heavy metal contamination level of dust. The health risk due to exposure to heavy metals in dust was analyzed by the Health Risk Assessment Model of US EPA. The results show that the arithmetic means of As, Co, Cr, Cu, Hg, Mn, Ni, Pb and Zn are 23.3, 16.4, 1591.8, 178.2, 0.243, 346.5, 40.2, 1,586.2 and 1,918.8 mg kg?1, respectively, which are higher than the background values of Shaanxi soil, especially for Cr, Cu, Hg, Pb, and Zn. The mean values of I geo reveal the order of Pb > Zn > Cr > Hg > Cu > As > Co > Ni > Mn. The high I geo of Cr, Cu, Hg, Pb and Zn in dust indicates that there is considerable pollution from Cr, Cu, Hg, Pb and Zn, while the low I geo of As, Co, Mn and Ni presents no pollution in dust. The assessment results of PI support the results of I geo, and IPI indicates heavy metals in dust polluted seriously. The health risk assessment shows that ingestion of dust particles is the route for exposure to heavy metals from dust, followed by dermal adsorption. Exposure to As, Cr and Pb from dust may pose a potential health threat to children and adults. The risk of cancer from As, Co, Cr and Ni due to dust exposure is low.  相似文献   

20.
Heavy metal contamination was the main environmental problem around the Jinchang Ni–Cu mine area of Gansu, Northwest China. The concentration of heavy metals (Cr, Cu, Ni, Pb, and Zn) in various environmental mediums around the Jinchang Ni–Cu mine area were analyzed using atomic absorption spectrometry (AAS). The different chemical speciation of heavy metals was extracted using BCR (European Community Bureau of Reference) sequential extraction procedure, and the concentration of chemical speciation of each heavy metal was measured by inductively coupled plasma-atomic emission spectrometry. The results showed that Cu and Ni were the most important heavy metal pollutants in various mediums including cultivated soils, dust on slagheap surfaces, tailings, and sediments in waste water drains. In the tailings and sediments, the concentrations of Ni were obviously higher than those of Cu, whereas, in the soil and dust, the concentrations of Cu were higher than those of Ni. Analysis of chemical speciation indicated that Cr and Zn were mainly in residual fraction; Cu was mainly in oxidizable fraction; Ni was mainly in reducible fraction and acid soluble fraction; and Pb was mainly in reducible fraction and residual fraction. The extent of contamination of various environmental mediums was different because the heavy metals were derived from different sources. Furthermore, the mobility of various heavy metals was different because of the different distribution of chemical speciation.  相似文献   

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