Terrestrial snails as quantitative indicators of environmental metal pollution

Concentrations of cadmium, lead, copper and zinc were measured in individuals of Arianta arbustorum from different urban sampling sites. In comparison to snails from a reference site, the animals collected in the city showed higher concentrations of cadmium, lead, and copper, indicating elevated levels of metal pollution. The most pronounced difference in tissue concentrations between control animals and contaminated snails was observed for lead. Within the city, metal levels in snails differed significantly, even between adjacent populations. Arianta arbustorum is a suitable species for biomonitoring, because it is widespread, resident and easy to collect; it has a high capacity for metal accumulation and shows different concentrations depending on metal contamination of the sampling area. An interspecific comparison of metal concentrations in terrestrial gastropods was conducted to define background levels and classes of burden. Three pollution levels are distinguished on the basis of the snails' metal burden: no pollution (class 1: reference sites), moderate (class 2: traffic and other human activities in urban areas), and high pollution (class 3: mining and heavy industry).     

The occurrence of heavy metals in irrigated and non-irrigated arable soils,NW Albania

The study analysed the content of heavy metals in surface soil and sediment samples from the Bregu i Matit Plain in NW Albania in relation to irrigation in order to evaluate the soil pollution and the potential risk to human health. Evaluation of soil pollution was performed using the enrichment factor and geo-accumulation index. Contents of cadmium, chromium and nickel of irrigated soils were significantly higher than those of non-irrigated soil, while contents of lead (in three of the irrigated locations), zinc and arsenic (in one of the irrigated locations) were significantly lower. Correlation analysis (CA) and principal component analysis (PCA) indicated that the primary source of the first three metals was irrigation, and the last three metals were originated from other anthropic sources, like the use of chemicals, etc. Enrichment factor (E _f) calculation showed that irrigated soils were most enriched in cadmium, chromium, copper and nickel. Index of geo-accumulation (I _geo) revealed that arable soils of Bregu i Matit are unpolluted to moderately polluted with cadmium, chromium, copper and zinc and moderately to strongly polluted with nickel and arsenic. The presence of heavy metals in the studied soils indicates a potential risk of transfer of these elements in the food chain. Therefore, further studies on the speciation of heavy metals in the studied soils in order to evaluate their mobility are needed.     

Analysis of mosses and topsoils for detecting sources of heavy metal pollution: multivariate and enrichment factor analysis

In order to assess the contribution of emission sources to the pollution of areas remote from industrial facilities, a combined approach of enrichment factor analysis and multivariate statistics was used for detecting the origin of heavy metal pollution in the Zlatibor ecosystem, in Serbia. Samples of moss (Pleurozium schreberi, Hylocomium splendens, Scleropodium purum, Hypnum cupressiforme and Thuidum delicatulum) and of topsoil (0-5 cm) were collected in 2005. The concentrations of seven heavy metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) were determined in moss and soil samples by atomic absorption spectrometry. The results obtained by enrichment factor analysis and two multivariate statistical methods, principal component analysis and cluster analysis, enabled discrimination of the lithologic and anthropogenic sources of heavy metals in the mosses. Enrichment factors, calculated to evaluate the contribution to the metal content in moss from anthropogenic sources, revealed pollution of the investigated area by Cd and Pb, originating from long-range transport and fossil fuel burning.     

Source identification study of heavy metal contamination in the industrial hub of Unnao,India

India's Unnao region is home to many leather-treatment facilities and related industries. Industrial and agricultural waste leads to heavy metal contamination that infiltrates groundwater and leads to human health hazards. This work measured the amount of heavy metal in groundwater at specific sites near the industrial facilities in Unnao and identified potential sources of contamination as anthropogenic or lithogenic. Groundwater samples were taken from 10 bore well sites chosen for depth and proximity to industry. Data obtained from sample sites was interpreted using a multivariate statistical analytical approach, i.e., principal component analysis, clustering analysis, and correlation analysis. The results of the multivariate analysis showed that cadmium, copper, manganese, nickel, lead, and zinc were correlated with anthropogenic sources, while iron and chromium were associated with lithogenic sources. These findings provide information on the possible sources of heavy metal contamination and could be a model for assessing and monitoring heavy metal pollution in groundwater in other locales. This study analyzed a selection of heavy metals chosen on the basis of industries located in the study area, which might not provide a complete range of information about the sources and availability of all heavy metals. Therefore, an extended investigation on heavy metal fractions will be developed in further studies.     

Identification of soil heavy metal sources from anthropogenic activities and pollution assessment of Fuyang County, China

Understanding regional variations of soil heavy metals and their anthropogenic influence are very important for environmental planning. In this study, 286 surface soil samples were collected in Fuyang county, and the 'total' metals for copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd) and nickel (Ni) were measured in 2005. Statistic analysis showed that Cu, Zn, Pb and Cd had been added by exterior factors, and Ni was mainly controlled by natural factors. The combination of multivariate statistical and geostatistical analysis successfully grouped three groups (Cu, Zn and Pb; Cd; and Ni) of heavy metals from different sources. Through pollution evaluation, it was found that 15.76% of the study area for Cu, Zn and Pb, and 46.14% for Cd suffered from moderate or severe pollution. Further spatial analysis identified the limestone mining activities, paper mills, cement factory and metallurgic activities were the main sources for the concentration of Cu, Zn, Pb and Cd in soils, and soil Ni was mainly determined by the parent materials.     

钼矿区周边农田土壤中重金属污染状况的分析与评价

对钼矿区周边农田土壤重金属污染情况进行了详细研究.选择该矿区受污染农田土壤样本80个,采用HNO3-HF-HClO4混酸对土壤样品进行处理,运用欧共体参比司推荐的BCR三步连续提取法进行化学形态分析;使用等离子体发射光谱仪(ICP-AES)测定土壤样品中Mo、Pb、As、Hg、Cr、Cd、Zn、Cu、Ni的全量及各种化学形态的含量并进行评价,同时对矿区地下水进行分析;采用spas软件进行数据分析.结果表明,矿山周边农田土壤重金属主要污染物为Cd、Hg并伴有Cr污染;Nemerow综合指数6.81,综合评价结果为该区土壤已受严重污染;Cd与As污染来源基本相同,Cu、Ni、Zn污染来源基本相同,Hg有独立的污染来源;重金属中化学形态分布为残余态>有机结合态>氧化结合态>酸可提取态;重金属Cr及Hg的有效态比例较大,可能会影响农作物的正常生长;矿山周边农田土壤重金属污染的原因可能是污染地下水的浇灌,矿石的开采、运输和大气降尘等过程;有机农药及塑料农用制品的施用过程,自然成土、矿物的伴生及其转化等过程.     

Impact of overland traffic on heavy metal levels in highway dust and soils of Istanbul, Turkey

The purpose of this study was to investigate the impact of overland traffic on the spatial distribution of heavy metals in urban soils (Istanbul, Turkey). Road dust, surface, and subsurface soil samples were collected from a total of 41 locations along highways with dense traffic and secondary roads with lower traffic and analyzed for lead (Pb), zinc (Zn), and copper (Cu) concentrations. Statistical evaluation of the heavy metal concentrations observed along highways and along the secondary roads showed that the data were bimodally distributed. The maximum observed Pb, Zn, and Cu concentrations were 1,573, 522 and 136 mg/kg, respectively, in surface soils along highways and 99.3, 156, and 38.1 mg/kg along secondary roads. Correlation analysis of the metal concentrations in road dust, surface and 20-cm depth soils suggests the presence of a common pollution source. However, metal concentrations in the deeper soils were substantially lower than those observed at the surface, indicating low mobility of heavy metals, especially for Pb and Zn. A modified kriging approach that honors the bimodality of the data was used to estimate the spatial distribution of the surface concentrations of metals, and to identify hotspots. Results indicate that despite the presence of some industrial zones within the study area, traffic is the main heavy metal pollution source.     

某钢丝绳典型产业区土壤重金属含量现状调查

以钢丝绳产业集聚区内的土壤为研究对象,采集和分析产业区中心河两边淹水环境下的水稻田、少用受污染河水灌溉的棉花田及不用受污染河水灌溉的蔬菜地样本,结果表明,产业区内土壤中铅和锌的含量明显高于产业区外。产业区内除水稻田土壤中铅的质量比超过评价参比值外,其他灌溉方式下土壤中铅和锌的质量比均未超过《土壤环境质量标准》（GB 15618-1995）中的二级标准（pH值＞7）。统计分析表明,土壤中的重金属含量与废水灌溉方式有关,该产业区内土壤外源重金属来自钢丝绳产业的可能性很大。在不同的灌溉方式下,土壤剖面样品中的重金属含量随着土壤深度增加呈现降低的趋势,2010年和2011年的测定结果无显著差异。     

Water-soluble species and heavy metal contamination of the petroleum refinary area,Jordan

The levels of lead, cadmium, copper, zinc, aluminum, chromium, and iron in street dust, soil, and plants in the Jordanian petroleum refinery were determined using flame and graphite-furnace atomic absorption spectrophotometry. Major cations (Li+, Na+, NH4+, K+, Mg2+, and Ca2+) and anions (F-, Cl-, NO3-, SO4(2-), and Br-) were also determined using suppression mode ion chromatography. Generally, higher levels of the heavy metals studied were found in street dust samples than in soil samples. On the other hand, except Cl-, and Li+ ions, other anions and cations showed higher concentrations in soil than in street dust samples. For plant samples, unwashed samples showed higher levels of heavy metals than their washed counterparts, indicating that dust fall is a source of heavy metal contamination.     

典型涉污企业周边土壤重金属污染特征及潜在生态风险评价

分析和评价典型涉污企业周边土壤环境质量,对于加强企业用地环境风险管控,实施土壤重金属污染精准防控,进一步保障农产品质量安全具有重要意义。以18类典型涉污企业周边土壤为研究对象,对475家企业周边的2 017个监测样点进行土壤重金属Cd、As、Pb、Hg、Cr、Cu、Zn和Ni元素含量测定,并采用主成分分析法、Hakanson 潜在生态风险指数法进行分析及评价。结果表明:典型涉污企业周边土壤重金属污染以Cd、Pb和As元素为主,各元素含量超过土壤污染风险筛选值的样品比例为9.82%~31.0%,超过土壤污染风险管控值的样品比例为4.46%~13.1%,其次是Zn、Cu、Hg和Ni,Cr无明显污染;主要污染元素Cd、Pb、As、Zn和Cu来自相同污染源且主要分布在有色金属矿采选业(B9)、黑色金属冶炼和压延加工业(C31)、有色金属冶炼和压延加工业(C32)、生态保护和环境治理业(N77)等行业企业周边;黑色金属冶炼和压延加工业(C31)、有色金属矿采选业(B9)、有色金属冶炼和压延加工业(C32)等行业企业周边土壤重金属潜在生态风险等级较高,中等风险及以上比例分别为76.0%、53.0%和54.1%。可见,典型涉污企业周边土壤重金属存在一定程度的污染,尤其是有色金属矿采选业(B9)等采矿业以及黑色金属冶炼和压延加工(C31)等制造业等,污染程度高,潜在生态风险大,需要加强监测和管控。     

Effects of lead and zinc mining contamination on bacterial community diversity and enzyme activities of vicinal cropland

In the process of mining activity, many kinds of heavy metals enter into soils with dust, causing serious contamination to the environment. In this study, six soils were sampled from cropland at different distances from a lead/zinc mine in Heilongjiang Province, China. The total contents of lead and zinc in the vicinal cropland exceeded the third level of environmental quality standard for soil in China, which indicated that soils in this area were moderately contaminated. Bacterial community diversity and population were greatly decreased when the concentrations of lead and zinc were beyond 1,500 and 995 mg kg(-1), respectively, as analyzed by plate counting and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The bands of DGGE patterns varied with the degree of contamination. The activities of soil urease, phosphatase, and dehydrogenase were negatively correlated with the concentrations of lead and zinc. The highest inhibitory effect of heavy metals on soil enzyme activities was observed in urease. It was noted that PCR-DGGE patterns combined with soil enzyme activity analysis can be indices for the soil quality assessment by heavy metal contamination.     

Seasonal and spatial distribution of trace elements in the water and sediments of the Tsurumi River in Japan

The Tsurumi, a class-one Japanese river, has a significant metal loading originating from urban environment. Water and sediment samples were collected from 20 sites in winter and summer, 2009 and were analyzed to determine and compare the extent of different trace element enrichment. A widely used five-step sequential extraction procedure was also employed for the fractionation of the trace elements. Concentrations of zinc, copper, lead, chromium, and cadmium were three to four times higher than that of reference values and downstream sediments are much more polluted than the upstream sites. Geochemical partitioning results suggest that the potential trace metal mobility in aquatic environment was in the order of: cadmium > zinc > lead > copper > cobalt > chromium > molybdenum > nickel. About 80.2% zinc, 77.9% molybdenum, 75.3% cobalt, 63.7% lead, 60.9% copper, 55.1% chromium, and 39.8% nickel in the sediment were contributed anthropogenically. According to intensity of pollution, Tsurumi river sediments are moderately to heavily contaminated by zinc, lead, and cobalt. Enrichment factor values demonstrated that zinc, lead, and molybdenum have minor enrichment in both the season. The pollution load index (PLI) has been used to access the pollution load of different sampling sites. The area load index and average PLI values of the river were 7.77 and 4.93 in winter and 7.72 and 4.89 in summer, respectively. If the magnitude of pollution with trace metal in the river system increases continuously, it may have a severe impact on the river’s aquatic ecology.     

Risks associated with the mining of Pb–Zn minerals in some parts of the Southern Benue trough,Nigeria

The environmental effects of the mining of lead–zinc mineralization in Enyigba area, Southern Benue trough were examined. The samples used for this study were obtained from abandoned mine sites, mine tailings, streams, hand-dug wells, mine pond and borehole. Collected samples were subjected to X-ray fluorescence, X-ray diffraction analyses, atomic absorption spectrometry and permeability tests. These were done using standard laboratory equipment and procedures. The concentrations of heavy metals present in analysed water samples fall below the world health organizations’ (WHO) acceptable limits. Conversely, the soil, mine tailings and stream sediments indicate appreciable pollution level by some potential toxic metals (PTMs). Consequently, the habitual use of these soils for construction purpose by inhabitants has possible health hazards. The shaly lithology underlying the area is increasingly affected by weathering and lateritization, thus improving its permeability and the easiness with which PTMs can be conducted to the water table by leachate. Regular monitoring assessment is recommended to ensure adherence of miners operating in the area to existing environmental laws.     

燃煤电厂周边大气重金属污染特征及来源解析

为探究燃煤电厂周边大气环境中重金属的污染特征与来源,对广东某山区燃煤电厂周边地区环境和污染源的重金属进行测定,分析其污染特征,采用因子分析法和Pb同位素示踪法对环境中的重金属进行来源解析。结果表明,研究区域室内积尘中重金属浓度水平明显高于土壤重金属,污染空间分布与当地气象条件相关。环境空气TSP中重金属主要来自2个污染源,Cd、Pb、As主要来自电厂燃煤,Ca、Mn、Al、Mg主要来自土壤扬尘。TSP、降尘、积尘样品所含的Pb均与电厂采集的煤、炉渣、粉煤灰样品所含的Pb具有同源性,与其他污染源同源性不明显,说明研究区域大气中Pb污染主要来自电厂燃烧所排放的烟尘,其他污染源影响不大。     

云南个旧土壤农作物重金属污染特征及潜在风险

在实地调查和实验室分析的基础上,对云南省个旧市大屯镇土壤农作物重金属污染状况进行了评价。结果显示:个旧市大屯镇调查区域土壤中Pb、Zn、Cd、As平均质量分数分别为943. 5、454. 8、3. 4、302. 1 mg/kg,分别为国家农用地土壤污染风险管控标准筛选值的7. 8、1. 8、11. 2、10. 1倍,土壤污染严重。土壤Cd的生态危害最强,As、Pb的生态危害次之,Zn表现为轻微的生态危害。从潜在生态危险指数来看,所采集的土壤样品皆表现为极强的生态危害。所采集农作物与食品安全国家标准对比,结果显示,大米中Pb、Cd和As的超标率分别为35%、55%和100%;玉米中Pb、Cd和As的超标率分别为13%、0%和0%;小苦菜Pb、Cd和As的超标率分别为100%、60%、100%;小米菜中Pb、Cd和As的超标率均为100%,蔬菜类的重金属超标情况相对于谷物类较为严重。研究区域土壤样品总量Pb、Zn与有效态皆呈极显著正相关关系,总量Cd与有效态呈弱正相关关系,总量As与有效态表现为相关性不显著。     

包头某铝厂周边土壤重金属污染及健康风险评价

以包头市某铝业周边500 m内土壤为研究对象,测定其东北、东南、西北、西南4个方向不同水平距离及深度处土样中Cu、Cd、Pb、Zn、Ni和Cr的含量,并采用地累积指数法和健康风险评价法对重金属污染状况进行评价。结果表明,该区域表层土壤中6种重金属普遍高于内蒙古土壤背景值,且在西南方向50 m处含量最高,人类活动对该区域重金属干扰强烈,而风向对重金属分布影响不大;铝厂周围土壤中Cd、Pb处于中污染-重污染,Cu和Ni处于无污染-中污染,Zn和Cr为无污染,各金属污染程度随土壤深度的增加而减轻;健康风险评价表明,研究区域内Cu、Pb、Ni和Cd均不存在非致癌健康风险,而Cd的致癌危害虽在可接受范围内,但已存在潜在致癌风险,Ni的致癌健康风险指数已超过预警值,应予以高度重视和防治。     

Petroleum contaminated soil in Oman: Evaluation of bioremediation treatment and potential for reuse in hot asphalt mix concrete

This paper presents a study that aims at evaluating the leaching characteristics of petroleum contaminated soils as well as their application in hot mix asphalt concrete. Soil samples are environmentally characterized in terms of their total heavy metals and hydrocarbon compounds and leachability. The total petroleum hydrocarbon (TPH) present in the PCS before and after treatment was determined to be 6.8% and 5.3% by dry weight, indicating a reduction of 1% in the TPH of PCS due to the current treatment employed. Results of the total heavy metal analysis on soils indicate that the concentrations of heavy metals are lower when extraction of the soil samples is carried out using hexane in comparison to TCE. The results show that the clean soils present in the vicinity of contaminated sites contain heavy metals in the following decreasing order: nickel (Ni), followed by chromium (Cr), zinc (Zn), copper (Cu), lead (Pb), and vanadium (V). The current treatment practice employed for remediation of the contaminated soil reduces the concentrations of nickel and chromium, but increases the concentrations of all remaining heavy metals.     

Roadside Rhododendron pulchrum leaves as bioindicators of heavy metal pollution in traffic areas of Okayama, Japan

The leaves of roadside Rhododendron pulchrum Sweet were examined as a bioindicator of traffic-related heavy metal pollution in Okayama. Total contents of heavy metals in roadside soil and the R. pulchrum leaves were determined. Results of correlation analyses showed significant correlations among Pb, Ni, and Zn contents of roadside soil and leaf samples. These results suggest that R. pulchrum is a useful bioindicator of heavy metal pollution in traffic areas. To identify traffic-related heavy metal pollution sources, traffic-related materials such as tires, asphalt pavement, and road paint were collected and analyzed. The results of analyses of our data show that Zn is emitted mainly from the abrasion of tires; Cr is emitted mainly from wear of the asphalt pavement. Furthermore, the respective lead isotope ratios in R. pulchrum leaves, soil, roadside dust, and traffic-related materials were measured using inductively coupled plasma mass spectrometry. The isotopic compositions of lead in R. pulchrum leaves were 207Pb/206Pb = 0.861-0.871 and 208Pb/206Pb = 2.093-2.127, which agrees well with ratios in automobile wheel balance weights, suggesting that lead-containing products associated with automobiles, such as wheel balance weights, contribute to traffic-related lead pollution.     

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。     

Effects of an Oil Spill on Soil Physico-Chemical Properties of a Spill Site in a Typic Udipsamment of the Niger Delta Basin of Nigeria

Physico-chemical analysis of soil samples at an oil spill site in a Typic Udipsamment of the Niger Delta Basin of Nigeria showed that the total hydrocarbon content of top soil layers ranged from 18.6 to 23.6 ppm in the heavy impact zone and the oil had penetrated to a depth op 8.4 m. The concentration of hydrocarbons in the medium impact zone ranged from 10.04 to 10.38 ppm while hydrocarbons were not detected in 85% of samples from the unimpacted reference zone. Heavy metal concentration measurements in the soil revealed a significant build-up (P < 0.05) of lead, copper and zinc in the heavy impact zone. Other quality parameters including electrical conductity, exchangeable cations, total nitrogen and available phosphorus in impacted soils were relatively low, while the total organic carbon was high compared with the reference site. Textural class of soil from the different depths showed a predominantly brown sand at the topsoil, loamy sand and grey coarse sand at medium depths, and grey coarse sand and greyish sandy clay at greater depths.