Spatial-Based Assessment of Heavy Metal Contamination in Agricultural Soils Surrounding a Non-ferrous Metal Smelting Zone

This work aimed to assess the degree of anthropogenic influence and severity of heavy metal from a non-ferrous metal smelting industrial zone. The results suggested that anthropogenic inputs played a dominant role in the enrichment of Cu, Zn, Pb, Sb and Cd. These metals showed similar spatial distribution patterns. Multivariate analysis showed strongly significant relationships between Cu–Zn,Cd–Zn, Cd–Sb, Sb, Sb, Cu, Zn, and Pb. Strong relationship was found between Cr, Ni, Cu, Zn, Sb and organic matter in soil. Risk evaluation results within the soil investigated profile was in the following order: Cd > Sb > Cu > Zn > Pb. Nemerow’s synthetical contamination index revealed that there is substantial ecotoxicological risk among the sampling sites with 8 of 9 of these locations exceeding the Nemerow criteria for seriously impacted sites and another site was close to moderately polluted domain.     

The Effect of Liming and Sewage Sludge Application on Heavy Metal Speciation in Soil

The aim of this paper is to assess the effect of liming and low doses of municipal sewage sludge (5%, 10%, 15% of the soil mass) on lead, chromium and nickel speciation in soil. The 420-day experiment was carried out in laboratory conditions. In all the samples lead, chromium and nickel concentration was determined with the ICP-AES method, while the content of those metals in different fractions was measured with the seven-step Zeien and Brümmer method, on the 30th and 420th days of the experiment. Sewage sludge doses significantly diversified lead, chromium and nickel amounts in the soil. The highest dose of sludge caused a significant increase, compared to the control, in the content of those metals. In the sludge the dominant forms of metals tested in the experiment were lead and chromium bound to organic matter (F4) as well as nickel bound to amorphous iron oxides (F5). Liming decreased the mobility of the metals in the soil.     

公路旁土壤中重金属污染分布及潜在生态危害的研究

[目的]研究公路旁土壤中重金属污染的分布及潜在生态危害。[方法]以319国道龙岩市新罗区路段为研究区,对耕作土采样,用原子吸收光谱法和分光光度法分析土壤中重金属Cd、Pb、Cu、Zn和Cr含量,并与对照区比较,同时采用Lars Hakanson指数法评价重金属的潜在生态危害。[结果]研究区表层土壤cd[(1.48±0.60)mg/kg]、Pb[(160.17±55.99)mg/kg]、cu[(38.44±12.16)mg/kg]、Zn[(80.35±6.60)mg/kg]、Cr[(79.50±23.58)mg/kg]含量显著高于对照区(P<0.001),Cd和Pb为重度污染(100％),Cu和Cr为轻微污染(分别占监测点位的55.8％和35.3％);土壤对重金属元素的吸收及污染程度:Pb>Cd>Cu>Cr>zn。潜在生态危害综合指数为253.0,主要污染为Cd,达到很强的生态危害,其次是Pb、Cu、Cr和Zn,均为轻微生态危害;潜在生态危害地带自公路起向其两侧扩散范围约为150 m。[结论]公路旁土壤中重金属以Cd、Pb污染为主,属于中等生态危害,污染物主要来源于机动车辆燃料和轮胎中所含微量重金属成分。     

Fluoride Contamination and Fluorosis in Rural Community in the Vicinity of a Phosphate Fertilizer Factory in India

We studied chronic fluoride intoxication in 10 villages of Udaipur receiving F emissions from phosphate fertilizer factories. Although fluoride remained below permissible limit in most of the drinking water samples, the incidence of fluorosis in adults as well as in children was surprisingly high. Khemli appeared to be the most affected village (with >48% cases) where, about 93% of 2 h air samples contained fluoride above 2.0 μg m⁻³ and crops and vegetable F ranged from 27.5 to 143.4 μg g⁻¹. Concentrations of fluoride and inorganic P in urine showed asynchrony and were well linked with prevalence of fluorosis. The study indicated that air-borne fluoride was the major factor for higher prevalence of fluorosis in these rural areas.     

Utility of Caenorhabditis elegans for Assessing Heavy Metal Contamination in Artificial Soil

There is an increasing need for the development of soil bioassay protocols. Currently the only internationally standardized soil test organism is the lumbricid earthworm Eisenia fetida. Many alternate soil test organisms have been proposed. This work compares Caenorhabditis elegans to several other test organisms, including E. fetida, for heavy metals in soil. In this evaluation, such factors as ease of testing and culturing, duration of testing, soil volume needed, and the sensitivity of the organism were considered. Results show that C. elegans is more sensitive than most other organisms evaluated and is similar in response to E. fetida. The second issue compares C. elegans LC₅₀ values to heavy metals criteria specified in the US EPA regulations for land application of sewage sludge. Currently, the regulations are set on total metals in the soil and do not consider bioavailability of the metals. Regulations do not consider soil physiochemical properties, such as organic matter content, clay content, and cation exchange capacity, which have been shown to affect the availability of metals to soil organisms. While the C. elegans LC₅₀ values are above standard values in artificial soil, work in our lab indicates that the LC₅₀s are below regulation values for other soil types. Due to the ease of culturing and testing, good sensitivity, along with the wealth of biological information and ecological relevance, C. elegans is a good organism for use in soil bioassays. Received: 2 June 1999/Accepted: 13 January 2000     

Contamination of Cows Milk by Heavy Metal in Egypt

The present investigation was carried out to assess the residues levels of five metals (Cadmium, Copper, Lead, Iron and Zinc) in cow milk collected from different sites in El-Qaliubiya governorate, Egypt. A total of 100 cow milk samples were collected from twenty cows in each location sites during the morning milking in the period from March to April, 2011. The highest average concentration are those of iron (16.38 μg/g) followed by zinc (10.75 μg/g) and lead (4.404 μg/g), while the lowest mean concentration are 2.836 and 0.288 μg/g for copper and cadmium, respectively. The results showed that most of the milk samples from the different sites containing all the studied metals with concentration higher than those recommended for milk by international dairy federation standard and Codex.     

Soil Heavy Metal Contamination and Risk Assessment Around the Fenhe Reservoir,China

Heavy metal contamination in the soil around a water source is a particularly serious issue, because these heavy metals can be transferred into the water source and can pose significant human health risks through the contamination of drinking water or farmland irrigation water. In this paper, we collected surface soil samples from the area surrounding the Fenhe Reservoir. The concentrations of As, Cd, Cr, Cu, Hg, Ni, and Zn were determined and the potential ecological risks posed by the heavy metals were quantitatively evaluated. The primary inputs for As, Ni, and Zn were natural sources, whereas the other elements were derived from mainly anthropogenic sources. Hg displays more serious environmental impacts than the other heavy metals. The upper reaches of the reservoir, located in the northwest, display a higher potential ecological risk.     

Assessment of Heavy Metal Contamination in Roadside Surface Soil and Vegetation from the West Bank

Concentrations of heavy metals (Pb, Cd, Cu, Zn, Fe, Mn, Ni, and Cr) were investigated in roadside surface soil and the common perennial herb inula (Inula viscosa L., Compositae). Samples were collected at different distances (0–200 m) perpendicular to a main road that connects two main cities in the West Bank. Average concentrations of metals in soil samples were: Pb, 87.4; Cd, 0.27; Cu, 60.4; Zn, 82.2; Fe, 15,700; Mn, 224; Ni, 18.9; and Cr, 42.4 g · g^–1. In plant leaves, concentrations were: Pb, 7.25; Cd, 0.10; Cu, 10.6; Zn, 47.6; Fe, 730; Mn, 140; Ni, 4.87; and Cr, 7.03 g · g^–1. Roadside contamination was obvious by the significant negative correlations between concentrations of metals in soil and plant samples and distance from road edge. Only cadmium concentrations in soil and plant samples were not associated with roadside pollution. Roadside contamination in plants and soil did not extend much beyond a 20 m distance from road. I. viscosa reflected roadside contamination better than soil and their metal concentrations showed much less fluctuations than those in soil samples. Washing plant leaves decreased Pb and Fe concentrations significantly, indicating a significant aerial deposition of both. I. viscosa can be considered as a good biomonitor for roadside metal pollution.     

Liming Effects on Cadmium Stabilization in Upland Soil Affected by Gold Mining Activity

To reduce cadmium (Cd) uptake of plants cultivated in heavy metal–contaminated soil, the best liming material was selected in the incubation test. The effect of the selected material was evaluated in the field. In the incubation experimentation, CaCO₃, Ca(OH)₂, CaSO₄·2H₂O, and oyster shell meal were mixed with soil at rates corresponding to 0, 400, 800, 1600, 3200 mg Ca kg⁻¹. The limed soil was moistened to 70% of field moisture capacity, and incubated at 25°C for 4 weeks. Ca(OH)₂ was found to be more efficient on reducing soil NH₄OAc extractable Cd concentration, due to pH increase induced net negative charge. The selected Ca(OH)₂ was applied at rates 0, 2, 4, 8 Mg ha⁻¹ and then cultivated radish (Raphanus sativa L.) in the field. NH₄OAc extractable Cd concentration of soil and plant Cd concentration decreased significantly with increasing Ca(OH)₂ rate, since alkaline-liming material markedly increased net negative charge of soil induced by pH increase, and decreased bioavailable Cd fractions (exchangeable + acidic and reducible Cd fraction) during radish cultivation. Cadmium uptake of radish could be reduced by about 50% by amending with about 5 Mg ha⁻¹ Ca(OH)₂ without adverse effect on radish yield and growth. The increase of net negative charge of soil by Ca(OH)₂ application may suppress Cd uptake and the competition between Ca²⁺ and Cd²⁺ may additionally affect the suppression of Cd uptake.     

Nitrogen and Phosphorus Fertilizer Increases the Uptake of Soil Heavy Metal Pollutants by Plant Community

Soil heavy metal pollution is widespread around the world. Compared with hyperaccumulation plants, non-hyperaccumulator plant communities have many advantages in the remediation of heavy metals pollution in soil. The application of nitrogen (N) and phosphorus (P) is inexpensive and convenient, which can promote the growth of plant. N and P fertilizer might increase plant community remediation of heavy metal polluted soils. In our study, the effects of N and P fertilizer on remediation of soil Cd, Cu, Pb pollution by plant community were studied through a greenhouse experiment. Our results indicated that addition of N, P and N?+?P fertilizer increased plant community aboveground biomass. Simultaneously, addition of N and P fertilizer increased the accumulation of heavy metals in aboveground of the plant community and accelerated plants absorption soil heavy metals. Among them, N fertilizer had the best effect. Our results provide an inexpensive method for remediation heavy metal pollution of contaminated farmland, abandoned land and mine tailings, etc.

     

土壤重金属污染生态风险评价方法研究进展

城市化所导致的土壤环境恶化已成为影响居民健康的一个重要因素,土壤的重金属污染问题已成为研究的热点。该文综述了目前常用的土壤重金属污染生态风险评价方法 [形态分析法、TCLP(Toxicity characteristic leaching procedure)法、体外试验评估法、植物培养法、蚯蚓生态毒理法]。指出今后的研究重点是制定土壤重金属环境质量标准和建立完善的评价体系,确定植物重金属污染指示作用的重要性,利用地理信息系统(GIS)技术开展重金属污染填图及建立土壤重金属污染信息系统,这些研究可为土壤管理提供科学指导依据。     

Effects of Zinc Contamination on a Natural Nematode Community in Outdoor Soil Mesocosms

The effect of zinc on the indigenous nematode fauna of a sandy soil was determined in an experimentally contaminated outdoor field plot. The aims of the study were to describe and quantify the changes in density of separate nematode taxa and total nematodes, and the changes in the number of taxa, species diversity, community maturation, and species composition in response to zinc exposure with time, and to compare the observed responses with benchmark concentrations for soil as derived from the species sensitivity distribution (SSD) for zinc toxicity. Speciation of zinc in pore water was considered and CaCl₂-exchangeable zinc concentrations were used as a measure of the bioavailable zinc fraction. After contamination, a reduction of total zinc and an increase of labile sorbed zinc over time occurred, concurrent with various changes in soil and biological characteristics. Data analyses on the nematode species revealed different sensitivity levels for several population and community endpoints to zinc exposure. Based on no observed effect concentration (NOEC) values, the most sensitive community-level response was obtained with principal response curve (PRC) analysis, which incorporates all density data in a single analysis. The PRC-based community NOECs were 56, 100, and 100 mg total Zn/kg dry soil after 3, 10, and 22 months of exposure, respectively. Based on 0.01 M CaCl₂-exchangeable zinc, the community response appeared to increase, as NOECs were 4.9, 4.4, and 0.67 mg exchangeable Zn/kg dry weight. Total density was least sensitive, followed by diversity of taxa and the Shannon-Wiener index. NOECs for separate species covered a broad range from sensitive to tolerant species. This range of sensitivities was similar to the one found for other species groups tested in the field plot soil. A comparison was made between benchmark concentrations HC5 and HC50 derived from the general SSD of soil organisms for zinc and the nematode response data. These comparisons roughly confirm the predictions of the SSD model, that is, the community NOEC is in agreement with the benchmark that should protect the soil ecosystem's integrity, and large adverse effects were found at the benchmark derived for setting remediation urgency. Received: 9 November 2000/Accepted: 2 August 2001     

土法炼锌场地铅污染及其农作物和居民铅暴露评估

[目的]对土法炼锌场地居民铅暴露情况进行评估. [方法]以贵州省毕节市赫章县妈姑镇水塘村土法炼锌场地为暴露区一,妈姑镇何家冲村为暴露区二;妈姑镇水塘村无土法炼锌区及可乐乡和幺站镇为对照区.从暴露区一、二和对照区采集土壤;从暴露区一、二和幺站镇采集玉米的根、茎、叶、果实,和其他4种农作物以及动物内脏等样本,测定铅含量.从暴露区一、二随机采集血样130份、尿样141份,从幺站镇随机采集血、尿样各108份,测定血铅(BPb)、尿铅(UPb)等指标. [结果]暴露区一和暴露区二土壤含铅量分别为(144 572.917±49 811.950) mg/kg、(38 520.833±28 580.715) mg/kg;主要农作物含铅量为玉米0.2731 mg/kg、卷心菜0.0089 mg/kg、小白菜0.0533 mg/kg、白萝卜0.0044 mg/kg、土豆0.0336 mg/kg;主要可食性动物内脏铅含量为猪肝(6.9667±3.1960) mg/kg、猪肾(17.8333±10.6624) mg/kg、鸡肝(1.0487±0.5465)mg/kg、鸡肾(0.3307±0.221 5)mg/kg,均高于对照区(P＜0.05或P＜0.01).暴露区居民血、尿铅含量分别为169.446 μg/L、26.820 μg/gCr,与对照区居民相比,差异有统计学意义(P＜0.01). [结论]土法炼锌使当地土壤受到铅污染,农作物和动物内脏具有铅富集的特征,暴露区居民的血铅和尿铅均高于对照区.     

Heavy Metal Content of Potato and Corn Chips from Turkey

No abstract available.     

龙岩市小型冶炼厂铅危害情况调查

随着个体经济的发展，我市近几年新上了不少小型冶炼厂(乡镇企业)。众所周知，在冶炼过程中，含铅矿石经高温加热后有大量的铅烟逸出，经作业人员的呼吸道、消化道进入人体，引起神经、造血，消化、心血管系统及肾等一系列损害。为了解小型冶炼厂铅污染情况，为防治职业性铅中毒提供科学依据，笔者对我市6家小型冶炼厂2001—2004年作业场所监测情况与工人健康检查结果进行了分析，现报告如下。     

Heavy Metal Contamination in a Typical Mining Town of a Minority and Mountain Area,South China

This study was conducted in Dachang, a small mining town in Gaungxi Zhuang Autonomous Region in southern China. A total of 23 farmland soil samples and two atmospheric samples of particulate matter less than 10 microns (PM₁₀) were collected in this town. ICP-MS was used to analyze for 20 elements in each of the samples. All of the samples contained some level of heavy metals. The most commonly detected heavy metals detected in the soil samples were: Cd (up to 29.0 mg kg⁻¹), As (up to 776 mg kg⁻¹), Sb (up to 36.8 mg kg⁻¹), Pb (up to 582 mg kg⁻¹), Zn (up to 1379 mg kg⁻¹) and Cu (up to 156 mg kg⁻¹), Mn (up to 1476 mg kg⁻¹). The PM₁₀ content in air samples exceeded the Chinese standard by nearly ten-fold. The most commonly detected heavy metals detected in the PM₁₀ atmospheric samples were Cd (up to 210 mg kg⁻¹), As (up to 15239 mg.kg⁻¹), Sb (up to 445 mg kg⁻¹), Pb (up to 8053 mg kg⁻¹), Zn (up to 13151 mg kg⁻¹) and Cu (up to 673 mg kg⁻¹), Mn (up to 2826 mg kg⁻¹), Mo (up to 120 mg kg⁻¹). All of these heavy metals are associated with significant human health effects ranging from reduced intelligent quotients (IQs) in children (cf. Pb) to cancer (e.g., Cd and As). Müller Geo-accumulation Index (Igeo) and enrichment factor (EF) were used to assess the findings. The results to the two assessments showed the same ranking: Cd > As > Sb > Pb > Zn > Cu > Mn, which would imply that the particulate matter in ambient air was the source of the contamination in the soil. The correlation analysis supported this inference. Upon further examination, ore transportation through the town was identified as the most likely source of contamination. Therefore, steps should be taken to improve the management of the ore transportation in order to protect the farmland and the health of the residents.