Levels and speciation of heavy metals in soils of industrial Southern Nigeria

A knowledge of the total content of trace metals is not enoughto fully assess the environmental impact of polluted soils. Forthis reason, the determination of metal species in solution isimportant to evaluate their behaviour in the environment andtheir mobilization capacity. Sequential extraction procedure wasused to speciate five heavy metals (Cd, Pb, Cu, Ni and Zn) fromfour contaminated soils of Southern Nigeria into sixoperationally defined geochemical species: water soluble,enchangeable, carbonates, Fe-Mn oxide, organic and residual.Metal recoveries were within ± 10% of the independentlydetermined total Cd, Pb, Cu, Ni and Zn concentrations. The highest amount of Cd (avg. 30%) in the nonresidual fractionswas found in the exchangeable fraction, while Cu and Zn weresignificantly associated with the organic fraction. Thecarbonate fraction contained on average 14, 18.6, 12.6, 13 and11% and the residual fraction contained on average 47, 18, 33,50 and 25% of Cd, Pb, Cu, Ni and Zn respectively. Assuming thatmobility and bioavailability of these metals are related to thesolubility of the geochemical form of the metals, and that theydecrease in the order of extraction sequence, the apparentmobility and potential bioavailability for these five metals inthe soil were: Pb > Zn > Cu > Ni > Cd. The mobility indexes ofcopper and nickel correlated positively and significantly withthe total content of metals, while mobility indexes of cadmiumand zinc correlated negatively and significantly with the totalcontent of metals.     

水稻重金属含量与土壤质量的关系

根据“淮安市绿色食品基地调查以及相关研究”课题资料 ,分析了水稻中重金属含量与其土壤质量的关系。结果表明 ,重金属含量在水稻中的分布是 :根 >茎叶 >籽粒 ;水稻籽粒对重金属的吸收特点因其元素不同而差异较大 ,重金属元素被水稻糙米吸收的程度为 :砷 <镉 <汞 <铅 <锰 <铬 <铜 <锌 ;在糙米中检出的重金属铜和铬的含量与土壤中铜和铬的含量呈显著性相关关系 ,铅、锌、锰的含量与土壤中铅、锌、锰的含量相关关系不显著     

Recycling of complexometric extractants to remediate a soil contaminated with heavy metals

Equilibrations were performed with complexing reagent(s) to mobilise Cd, Cu, Mn, Ni, Pb and Zn from a contaminated urban soil. The metal-laden aqueous extract was treated with zero-valent magnesium (Mg0) or bimetallic mixture (Pd0/Mg0 or Ag0/Mg0) to precipitate the heavy metals from solution while liberating the chelating reagent(s). Post precipitation, the pH of aqueous supernatant fraction was readjusted to approximately 5 and the solution was re-combined with the soil particulates to extract more heavy metal pollutants. A sparing quantity of EDTA (10 mmoles) mobilised 32-54% of the 5 mmoles of heavy-metals from the soil with three cycles but only 0.1% of the iron was removed. Three successive extractions with a mixture of complexing reagents (3 mmoles), 1:1 EDTA plus HEDC [bis-(2-hydroxyethyl)-dithiocarbamate], mobilised approximately 49% of the Pb, approximately 18% of the Zn and approximately 19% of the Mn burden but only 7% of the Cu, and 1% of the Fe from this soil. An appreciable fraction of the mobilised Pb and Cu and a portion of the Zn was cemented to the surfaces of the excess magnesium whereas virtually all of the Fe and Mn was removed from solution as insoluble hydroxides.     

湖南省某冶炼厂周边农田土壤重金属污染及生态风险评价

利用野外采样与实验室分析相结合的方法,以湖南省某冶炼厂周边农田土壤(0~20 cm)为研究对象,监测了Cd、As、Pb、Cr、Cu、Zn、Hg等7种重金属的含量,并对重金属污染程度与潜在生态风险进行了评价。结果表明,7种重金属都存在不同程度的超标或污染,其中Cd、As、Pb等的污染较为严重。统计学分析结果表明,Pb、As、Hg、Zn、Cd等来源相同,可能主要都来自于人为污染,即冶炼作业造成的污染。7种重金属化学形态不尽相同:在重金属有效态中,Cd的水溶态和可提取态较高;Pb、Cu、Zn可还原态、可氧化态这两部分含量较高。而Hg、As、Cr的残渣态含量较高。风险评价代码评价结果表明,Cd的生态风险较高,4.5%的样点Cd为极高生态风险,52.8%的样点Cd为高生态风险,42.7%的样点Cd为中度生态风险;100%的样点Zn为中度生态风险;Cu有60.1%的样点属于低生态风险,39.9%的样点属于中度生态风险;As、Pb主要以低生态风险为主(所占比例分别为77.2%、80%);Hg主要以无生态风险为主(所占94.3%)。Hakanson潜在生态风险指数法计算的综合潜在生态风险指数(RI)的范围为46.4~1 627.5,表明研究区域农田土壤存在很高的生态风险。上述各项结果综合表明,研究区农田土壤受到了严重的重金属污染,由此引起的重金属生态风险应引起高度关注。     

大冶龙角山地区土壤中重金属污染现状与评价

为了研究大冶龙角山地区尾砂坝内尾砂排放对下游耕地土壤中重金属含量的影响，本文对尾矿坝及河流两岸的耕地进行布点采样，通过等离子体发射光谱仪（ICP—OES）测定土壤中A5、Cd、Cr、Cu、Pb、Zn6种重金属的含量，并用污染指数法进行分析评价。旨在调查研究的基础上，使人们认识当地重金属污染的严重性，加大环境保护力度。     

Heavy Metal Availability in Soil Amended with Composted Urban Solid Wastes

A study was performed to evaluate the pH and the availability of Zn, Cu, Mn, Pb, and Ni in soil amended with increasing doses of composted solid wastes, collected in Rio de Janeiro, Rio de Janeiro State and in Coimbra, Minas Gerais State, Brazil. The influence of the time elapsed between compost application to the soil and the sampling of the plant growth substrate (soil + compost) for pH and metal availability analyses was also examined. The availability of heavy metals in the soil, in the compost and in the substrate was evaluated using DTPA solution for metal extraction. The increase of the compost doses added to the soil resulted in the increase of the pH in the substrate. The addition of the compost from the bigger city, Rio de Janeiro, resulted in higher increase in soil pH and available Zn, Cu, Pb, and Ni levels as compared to the addition of the compost from the smaller city, Coimbra. Increasing the time elapsed between the compost application to the soil and the sampling of the mixture resulted in higher available Zn, Cu, Mn, and Pb levels. The addition of the compost from Rio de Janeiro resulted in substrate metal concentrations in the order Zn > Pb > Ni > Cu > Mn and for the Coimbra compost the metal concentrations in the substrate was Zn > Pb > Cu > Ni > Mn. The higher values of pH and available metals obtained for the bigger city were attributed to the greatest metal contamination of its compost.     

Ecotoxicological Assessment of the Impact of Residual Heavy Metals on Soil Nematodes in the Guadiamar River Basin (Southern Spain)

On 25 April 1998, as a consequence of the breaking of a dam containing the tailings of a pyrite mine, a land strip of approximately 43 km in length was covered with a layer of black sludge, containing high levels of heavy metals, along the Guadiamar River Basin (southern Spain). In this investigation we carried out an ecotoxicological assessment (field and laboratory studies) of the impact of residual heavy metals (Cu, Pb, Zn, Ni) on soil nematodes in the impacted riparian zone, two years after the huge mine spillage. Concentrations of residual heavy metals were significantly (P<0.05) higher at the impacted sampling sectors (S-2, S-3, S-4, S-5) than at the unpolluted (reference) sampling sector (S-1). Nickel however exhibited the lowest increases at the impacted sectors. As a consequence, correlation coefficients between concentrations of heavy metals and values of ecological indices were not significant for Ni. In contrast, copper, lead and zinc exhibited significant (P<0.05) negative correlation coefficients with ecological indices, particularly with diversity indices (including the~number of taxa). In addition, the toxicity of Cu and Pb to nematode test species (Aphelenchus avenae and Cephalobus persegnis) during short-term toxicity bioassays was much higher than the toxicity of Zn and Ni. We conclude that residual heavy metals were still influencing adversely the community of soil nematodes in the impacted riparian zone of the Guadiamar River Basin. Cu, Pb and, to a lesser extent, Zn would be major responsible for the observed impact.     

徽县铅锌冶炼区土壤中重金属的空间分布特征

采集甘肃省徽县铅锌冶炼区域土壤样品,分析该区域内重金属污染分布规律及污染特征。结果表明,表层土壤中Pb、Cd、Cu、Zn的平均含量分别为214、3.12、25.8、79.5 mg/kg。研究区域内重金属的分布特征显示,污染浓度由冶炼厂中心向四周递减。纵向0~30 cm范围内重金属含量逐渐降低,大部分重金属污染物集中在土壤表层的0~20 cm区域,其中0~2 cm区域内含量较高,Pb和Cd的最高含量分别达到3 877、24.8 mg/kg,与国家土壤环境质量二级标准(p H 6.5~7.5)(GB 15618—1995)相比,分别超标13、82倍,属于重度污染。重金属元素的分布与土壤有机碳含量及p H相关。冶炼厂周围的重金属污染应引起有关部门的高度重视,严格控制污染源,尽快采取措施以防止污染范围进一步扩大。     

Heavy metal binding fractions in the sediments of the Godavari estuary,East Coast of India

Sequential chemical extraction was used to study the operationally determined chemical forms of five heavy metals (Pb, Cu, Zn, Co and Ni) and their spatial distribution in the sediments. The binding behaviour of heavy metals associating with Fe–Mn oxides showed a good correlation towards Cu, Zn and Co, but moderate linear dependence with Ni and Pb. Among the five metals, correlation between Fe–Mn oxide bound Cu and Fe–Mn oxides (r = 0.95) is highest. The coefficient of determination (r ²) in organically bound heavy metals versus organic matter (OM) ranges from 0.772 to 0.952, which indicates a good linear dependence. The OM fraction in the sediments is more accessible to heavy metals and is the major ligand available for complexation. In particular, Zn and Cu are preferentially bound to OM. In general, Zn co-precipitation with carbonates is the dominant chemical form when Fe–Mn oxide and OM are less abundant. In this study, however, carbonates were less abundant, hence Zn bound to carbonates was less pronounced. Based on the results, even if the excessive binding sites are contained in the sediments, competition of various complexation reactions between sediment phases and heavy metals could dominate metal association.     

Vertical distribution of heavy metals in soil profile in a seasonally waterlogging agriculture field in Eastern Ganges Basin

The accumulation of heavy metals in soil and water is a serious concern due to their persistence and toxicity. This study investigated the vertical distribution of heavy metals, possible sources and their relation with soil texture in a soil profile from seasonally waterlogged agriculture fields of Eastern Ganges basin. Fifteen samples were collected at ～0.90-m interval during drilling of 13.11 mbgl and analysed for physical parameters (moisture content and grain size parameters: sand, silt, clay ratio) and heavy metals (Fe, Mn, Cr, Cu, Pb, Zn, Co, Ni and Cd). The average metal content was in the decreasing order of Fe?>?Mn?>?Cr?>?Zn?>?Ni?>?Cu?>?Co?>?Pb?>?Cd. Vertical distribution of Fe, Mn, Zn and Ni shows more or less similar trends, and clay zone records high concentration of heavy metals. The enrichment of heavy metals in clay zone with alkaline pH strongly implies that the heavy metal distributions in the study site are effectively regulated by soil texture and reductive dissolution of Fe and Mn oxy-hydroxides. Correlation coefficient analysis indicates that most of the metals correlate with Fe, Mn and soil texture (clay and silt). Soil quality assessment was carried out using geoaccumulation index (I _geo), enrichment factor (EF) and contamination factor (CF). The enrichment factor values were ranged between 0.66 (Mn) and 2.34 (Co) for the studied metals, and the contamination factor values varied between 0.79 (Mn) and 2.55 (Co). Results suggest that the elements such as Cu and Co are categorized as moderate to moderately severe contamination, which are further confirmed by I _geo values (0.69 for Cu and 0.78 for Co). The concentration of Ni exceeded the effects-range median values, and the biological adverse effect of this metal is 87 %. The average concentration of heavy metals was compared with published data such as concentration of heavy metals in Ganga River sediments, Ganga Delta sediments and upper continental crust (UCC), which apparently revealed that heavy metals such as Fe, Mn, Cr, Pb, Zn and Cd are influenced by the dynamic nature of flood plain deposits. Agricultural practice and domestic sewage are also influenced on the heavy metal content in the study area.     

Competitive sorption of Cd, Cu, Mn, Ni, Pb and Zn in polluted and unpolluted calcareous soils

The objectives of this study were to investigate competitive sorption behaviour of heavy metals (Cd, Cu, Mn, Ni, Pb and Zn) under different management practices and identify soil characteristics that can be correlated with the retention and mobility of heavy metals using 65 calcareous soil samples. The lowest sorption was found for Mn and Ni in competition with the other metals, indicating the high mobility of these two cations. The Freundlich equation adequately described heavy metals adsorption. On the basis of Freundlich distribution coefficient, the selectivity sequence of the metal adsorption was Cu?>?Pb?>?Cd?>?Zn?>?Ni?>?Mn. The mean value of the joint distribution coefficient (K _dΣsp) was 182.1, 364.1, 414.7, 250.1, 277.7, 459.9 and 344.8 l kg^?1 for garden, garlic, pasture, potato, vegetables, wheat and polluted soils, respectively. The lowest observed K _dΣsp in garden soil samples was due to the lower cation exchange capacity and lower carbonate content. The results of the geochemical modelling under low and high metal addition indicated that Cd, Ni, Mn and Zn were mainly retained via adsorption, while Pb and Cu were retained via adsorption and precipitation. Stepwise forward regression analysis showed that clay, organic matter and CaCO₃ were the most important soil properties influencing competitive adsorption of Cd, Mn, Ni and Zn. The results in this study point to a relatively easy way to estimate distribution coefficient values.     

Pollution, fractionation, and mobility of Pb, Cd, Cu, and Zn in garden and paddy soils from a Pb/Zn mining area

This study was conducted to investigate the pollution load index, fraction distributions, and mobility of Pb, Cd, Cu, and Zn in garden and paddy soils collected from a Pb/Zn mine in Chenzhou City, China. The samples were analyzed using Leleyter and Probst’s sequential extraction procedures. Total metal concentrations including Pb, Cd, Cu, and Zn exceeded the maximum permissible limits for soils set by the Ministry of Environmental Protection of China, and the order of the pollution index was Cd > Zn > Pb > Cu, indicating that the soils from both sites seriously suffered from heavy metal pollution, especially Cd. The sums of metal fractions were in agreement with the total contents of heavy metals. However, there were significant differences in fraction distributions of heavy metals in garden and paddy soils. The residual fractions of heavy metals were the predominant form with 43.0% for Pb, 32.3% for Cd, 33.5% for Cu, and 44.2% for Zn in garden soil, while 51.6% for Pb, 40.4% for Cd, 40.3% for Cu, and 40.9% for Zn in paddy soil. Furthermore, the proportions of water-soluble and exchangeable fractions extracted by the selected analytical methods were the lowest among all fractions. On the basis of the speciation of heavy metals, the mobility factor values of heavy metals have the following order: Cd (25.2–19.8%) > Cu (22.6–6.3%) > Zn (9.6–6.0%) > Pb (6.7–2.5%) in both contaminated soils.     

太原市大气颗粒物中重金属的污染特征及来源解析

为了解太原市采暖期大气颗粒物不同粒径中重金属的污染特征及其来源,于2012年10月—2013年2月对环境空气中颗粒物采样,用原子吸收分光光度法测定样品中Fe、Pb、Cu、Ni、Cr、Cd、Mn、Zn等8种元素的含量。结果表明,太原市采暖期重金属浓度从高到低依次为FePbMnZnCrCuNiCd。重金属Pb、Mn、Zn、Ni、Cd主要富集在PM2.5中;Cr主要富集在PM10中;Cu主要富集在PM5中;Fe主要在粒径大于2.5μm的粗粒子中富集。除Zn外,其他7种元素浓度均表现为灰霾期采暖期采暖前。通过主因子分析表明,太原市大气颗粒物中重金属主要来源于冶金、有机合成工业、燃煤、汽车尾气、土壤尘等。     

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.     

Contamination assessment of arsenic and heavy metals in a typical abandoned estuary wetland—a case study of the Yellow River Delta Natural Reserve

Coastal and estuarine areas are often polluted by heavy metals that result from industrial production and agricultural activities. In this study, we investigated the concentration trait and vertical pattern of trace elements, such as As, Cd, Ni, Zn, Pb, Cu, and Cr, and the relationship between those trace elements and the soil properties in coastal wetlands using 28 profiles that were surveyed across the Diaokouhe Nature Reserve (DKHNR). The goal of this study is to investigate profile distribution characteristics of heavy metals in different wetland types and their variations with the soil depth to assess heavy metal pollution using pollution indices and to identify the pollution sources using multivariate analysis and sediment quality guidelines. Principal component analysis, cluster analysis, and pollution level indices were applied to evaluate the contamination conditions due to wetland degradation. The findings indicated that the concentration of trace elements decreased with the soil depth, while Cd increases with soil depth. The As concentrations in reed swamps and Suaeda heteroptera surface layers were slightly higher than those in other land use types. All six heavy metals, i.e., Ni, Cu, As, Zn, Cr, and Pb, were strongly associated with PC1 (positive loading) and could reflect the contribution of natural geological sources of metals into the coastal sediments. PC2 is highly associated with Cd and could represent anthropogenic sources of metal pollution. Most of the heavy metals exhibited significant positive correlations with total concentrations; however, no significant correlations were observed between them and the soil salt and soil organic carbon. Soil organic carbon exhibited a positive linear relationship with Cu, Pb, and Zn in the first soil layer (0–20 cm); As, Cr, Cu, Ni, Pb, and Zn in the second layer (20–40 cm); and As, Cr, Cu, Ni, Pb, and Zn in the third layer (40–60 cm). Soil organic carbon exhibited only a negative correlation with Cd (P?I _geo values), which averaged less than 0 in the three soil layers, this finding indicates that the soils have remained unpolluted by these heavy metals. The mean concentrations of these trace elements were lower than Class I criteria. The degradation wetland restoration suggestions have also been provided in such a way as to restore the reserved flow path of the Yellow River. The results that are associated with trace element contamination would be helpful in providing scientific directions to restore wetlands across the world.     

渭河陕西段表层沉积物重金属污染特征及潜在风险

为了解渭河陕西段表层沉积物重金属的污染特征，采用ICP-MS分析了13个采样断面表层沉积物中As、Cd、Cr、Cu、Mn、Ni、Pb和Zn 8种重金属的含量，并对其来源和生态风险进行了评价。结果表明：渭河陕西段8种重金属的平均含量顺序依次为Mn > Zn > Cr > Cu > Ni > Pb > As > Cd；除Ni外的其余7种重金属的平均含量均超过陕西省A层土壤背景值。各断面表层沉积物重金属的潜在生态风险指数（RI）介于111.4~7 043.7，其中23.1%的断面有极强生态风险，46.2%的断面为中等生态风险，其余为轻微生态风险。Cd污染最为严重，对各断面的潜在生态风险介于较强生态风险与极强生态风险之间，对RI的贡献平均为85.2%；其余7种重金属在所有断面均属于轻微生态危害。渭河陕西段表层沉积物As、Cd、Cu和Zn主要为工业与农业来源；Cr和Ni主要为自然来源；Pb和Mn与城市污水和交通污染来源有关。     

真藓对碳酸盐型锰矿区重金属污染的指示意义

锰矿开采产生重金属污染,对周围环境造成影响,有必要对矿区重金属进行监测。研究以典型碳酸盐型锰矿——南茶锰矿(按职能划分为4个功能区:矿井区、废石区、选矿区、蓄矿区)为对象,以区域内真藓Bryum argenteum为材料,结合相关分析、聚类分析、主成分分析、变异系数等方法考察了真藓和土壤中重金属的含量及其可能的来源。结果表明:各功能区均受到不同程度的人为干扰,人为干扰越强,区域污染越严重。在不同污染梯度的功能区内,真藓的重金属(Fe、Mn、Zn、Cr、Ni、Ba、Co、Mo、Hg、Pb、Cd、Cu、Tl、As、Sb)含量与土壤重金属含量显著正相关(P<0.05),说明真藓是监测碳酸盐型锰矿重金属污染的有效指标。真藓指示南茶锰矿除了可能受到采矿活动的强烈影响外(Mn、Cu、Fe、Zn、Cr、Ni、Mo、Ba),还受到来自运输车辆的机械磨损、排放及采矿活动的复合污染(Tl、Cd、Pb、As、Sb),识别结果与区域重金属分布情况吻合,表明真藓具有识别重金属污染的能力。在今后碳酸盐型锰矿污染防治工作中,可将真藓作为重金属污染监测的生物材料。     

Heavy metal concentration and speciation of seven representative municipal sludges from wastewater treatment plants in Northeast China

The analysis of heavy metals is very important for assessing the feasibility of the agricultural utilization for the municipal sludge. In this paper, a four-step sequential extraction method was applied to extract heavy metals (Cu, Zn, Mn, Cr, and Ni) in municipal sludges from seven individual wastewater treatment plants located in Jilin and Heilongjiang Province, China, for estimating the mobility and bioavailability of the metal ions in the agricultural application. The total concentrations of heavy metals and their chemical fractions after the sequential extraction were determined. Principal component analysis (PCA) was applied to analyze the relations of heavy metals fractions in the municipal sludges. Experimental results indicated that the total concentrations of Cu, Zn, Cr, and Ni in all sludge samples were below the threshold values set out by the Chinese legislation (GB18918-2002). Specially, Zn had a high bioavailability and mobility, Cu and Cr had potential bioavailability, while Mn mainly existed in the residual fraction of municipal sludge. On the other hand, Ni had different mobility in different municipal sludge. PCA results were confirmed by the environmental behavior of heavy metals.     

Total concentrations, fractionation and mobility of heavy metals in soils of urban area of Guwahati, India

This work describes the results of assessment of the heavy metals, Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn in urban soil of Guwahati City, India from 31 sites of five different land use types covering residential, commercial, industrial, public utilities, and roadside. Sequential extraction procedure was used to evaluate the relative distribution of the eight metals in exchangeable, carbonate, reducible (Fe?CMn oxide), organic and sulfide, and residual fractions. Of the eight metals, Cd and Co occur in lower concentrations (Cd <?< Co) in all types of land, and concentration variation from one type of land use to another is not much significant for both the metals. Ni presence is more than Co, and the concentrations show some variation depending on land use status. Average Cr and Cu concentrations are ??100?mg/kg, but Cr has a significantly higher presence in industrial land use. The results are similar in case of Pb. The two metals, Mn and Zn have domination over the other metals, and the values are ??300?mg/kg. Industrial and roadside soil contains much more Mn, while commercial soil is most enriched with Zn. Of the metals, Ni has the largest proportion (~42%) bound to the exchangeable fraction and Co, Cr, and Pb also have appreciable proportion bound to the same fraction. A significant amount of Co is associated with carbonates. The reducible fraction has bound considerable quantity of Mn and Zn, while most of Cu is associated with the organic and sulfide fraction. Both Cd and Pb are dominantly associated with the residual fraction. Computation of the mobility factor of the metals indicates Mn to be the most mobile metal present in the soil samples.     

会泽某铅锌矿周边农田土壤重金属风险评价研究

采用现场采样与室内测试方法测定了会泽某铅锌矿周边农田土壤中Cd、As、Pb、Cr、Cu、Zn、Ni的含量,利用地积累指数法、潜在生态指数法对其土壤环境质量进行了评价,并应用US EPA推荐的健康风险评价法对重金属的健康风险进行了初步评价。结果表明,7种重金属均存在不同程度的富集或污染。多种重金属潜在生态风险指数属于中等及以上的风险状态,重金属潜在生态风险指数排序为CdPbAsCuNiZnCr。7种重金属在3种暴露途径下对儿童的非致癌健康风险均大于成人,但对成人、儿童均不存在显著的非致癌健康影响、非致癌健康总风险。As、Ni、Cr、Cd重金属的致癌风险值与4种元素总致癌风险值均未超出10-6~10-4的范围,尚不具备致癌风险。