A comparative study of heavy metal accumulation and antioxidant responses in Vaccinium myrtillus L. leaves in polluted and non-polluted areas

The purpose of this study was to explore a possible relationship between the availability of metals in soil (Cd, Fe, Mn, Pb and Zn) and their concentrations in leaves of Vaccinium myrtillus L. as a species which has been reported to be a successful colonist of acid-and-heavy metal-contaminated soil. Analysis also concerned the antioxidant response of plants from three heavily polluted (immediate vicinity of: zinc smelter, iron smelter and power plant) and three relatively clean sites (nature reserve, ecological site and unprotected natural forest community) in southern Poland. The contents of glutathione, non-protein thiols, protein, proline and activity of guaiacol peroxidase in leaves of bilberry were measured. Generally, the concentrations of metals in the HNO₃ and CaCl₂ extracants of the soil from the polluted sites were higher. Moreover, the antioxidant responses were also elevated in bilberries in the polluted sites. Significant positive relationships between Cd, Pb and Zn concentrations in soil and in the plants were found. In the leaves of V. myrtillus from the polluted sites, higher concentrations of Cd, Pb and Zn were noted (In Miasteczko ?l?skie respectively 6.26, 157.09 and 207.17 mg?kg^?1?d.w.). We found a positive correlation between the increase in the NPTs and protein contents as well as the Cd, Pb and Zn concentrations in V. myrtillus. Cd, Pb and Zn also decreased guaiacol peroxidase activity. However, the activity of this enzyme increased under Fe. A decreasing trend in glutathione contents was observed with increasing iron and manganese concentrations in bilberry leaves. Parameters such as protein, non-protein –SH groups and changes in GPX activity seem to be universal, sensitive and correlated well with heavy metal stress.     

Body metal concentrations and glycogen reserves in earthworms (Dendrobaena octaedra) from contaminated and uncontaminated forest soil

Stress originating from toxicants such as heavy metals can induce compensatory changes in the energy metabolism of organisms due to increased energy expenses associated with detoxification and excretion processes. These energy expenses may be reflected in the available energy reserves such as glycogen. In a field study the earthworm, Dendrobaena octaedra, was collected from polluted areas, and from unpolluted reference areas. If present in the environment, cadmium, lead and copper accumulated to high concentrations in D. octaedra. In contrast, other toxic metals such as aluminium, nickel and zinc appeared to be regulated and kept at low internal concentrations compared to soil concentrations. Lead, cadmium and copper accumulation did not correlate with glycogen reserves of individual worms. In contrast, aluminium, nickel and zinc were negatively correlated with glycogen reserves. These results suggest that coping with different metals in earthworms is associated with differential energy demands depending on the associated detoxification strategy.     

某矿区土壤和地下水重金属污染调查与评价

为了解湘南某矿区土壤和地下水重金属污染状况，对该矿区东河流域附近重金属污染源进行了调查，同时，对地下水和土壤样品进行了采样分析，结果表明：（1）该矿区东河流域附近的主要污染源有18个，其中有色金属选厂、尾矿库、采矿场和冶炼厂是排放重金属较多的污染源；（2）20个采样点中土壤重金属Pb、Cd、Zn、As和Hg大部分超过国家土壤环境质量标准（GB15618-1995），综合污染指数P综〉1，该矿区主要的重金属污染元素为Cd、As和Hg，且土壤中Cd、Zn和As的含量两两之间存在着极显著的正线性相关关系；（3）重金属元素在土壤中的纵向迁移不明显，该矿区附近20个采样点的地下水并未受到污染，综合污染指数P综〈1。20个采样点地下水Pb、Cd、Zn、As、Hg浓度均能达到地下水质量标准（GB／T14848．9）中的Ⅲ类标准。     

Bioaccumulation in Porcellio scaber (Crustacea, Isopoda) as a measure of the EDTA remediation efficiency of metal-polluted soil

Leaching using EDTA applied to a Pb, Zn and Cd polluted soil significantly reduced soil metal concentrations and the pool of metals in labile soil fractions. Metal mobility (Toxicity Characteristic Leaching Procedure), phytoavailability (diethylenetriaminepentaacetic acid extraction) and human oral-bioavailability (Physiologically Based Extraction Test) were reduced by 85-92%, 68-91% and 88-95%, respectively. The metal accumulation capacity of the terrestrial isopod Porcellio scaber (Crustacea) was used as in vivo assay of metal bioavailability, before and after soil remediation. After feeding on metal contaminated soil for two weeks, P. scaber accumulated Pb, Zn and Cd in a concentration dependent manner. The amounts of accumulated metals were, however, higher than expected on the basis of extraction (in vitro) tests. The combined results of chemical extractions and the in vivo test with P. scaber provide a more relevant picture of the availability stripping of metals after soil remediation.     

Eisenia fetida avoidance behavior as a tool for assessing the efficiency of remediation of Pb, Zn and Cd polluted soil

Remediation by means of soil leaching with ethylenediaminetetraacetic acid (EDTA) is capable of extracting the most labile soil fractions, leaving the residual metals in biologically non-available forms. We evaluated the feasibility of the standardized earthworm (Eisenia fetida) avoidance test for assessing the efficiency of soil remediation of Pb, Zn and Cd polluted soil. Chemical extraction tests (six-step sequential extraction, toxicity characteristic leaching procedure, physiologically based extraction test, diethylenediaminepentaacetic acid extraction) indicated that the mobility, oral bioaccessibility and phytoavailability of Pb, Zn and Cd were consistently reduced. However, the avoidance test showed no significant avoidance of polluted soil in favor of that which had been remediated. Pb, Zn and Cd accumulation in E. fetida mirrored the decreasing pattern of metal potential bioavailability gained by leaching the soil with increasing EDTA concentrations. The calculated bioaccumulation factors indicated the possibility of underestimating the metal bioavailability in soil using chemical extraction tests.     

巢湖表层沉积物中重金属的分布特征及其污染评价

以巢湖表层沉积物为研究对象,利用BCR连续提取法研究了沉积物中Cr、Co、Ni、Cu、Cd、Zn、V和Pb等8种重金属元素的分布特征,同时运用潜在风险指数法和地累积指数法综合评价了巢湖沉积物中重金属的生态风险。结果表明,巢湖沉积物中的重金属含量在空间上表现出东西高、中间低的分布特征。巢湖表层沉积物中Cr、Co、Ni、V和Cu 5种重金属都主要以残渣态为主,Zn和Cd主要以弱酸提取态为主,Pb以可还原态为主,同时,Co和Cu 2种元素的可交换态及可还原态含量占有较高比例,具有潜在危害性。相关性分析显示,Cr、Cu、Pb、Ni、Zn和Cd 6种重金属元素的来源和分布可能具有相似性,Co和V 2种重金属元素具有相似的地球化学行为且其主要来源可能与其他几种重金属不同。潜在生态风险指数评价结果表明,巢湖表层沉积物中8种重金属元素构成的生态危害顺序为:Cd>Pb>Co>Cu>Ni>Zn>V>Cr,Cd具有高的生态危害等级,其他7种重金属元素均为低生态危害等级。地累积指数法评价结果表明:巢湖沉积物重金属元素的富集程度为Cd>Zn>Pb>Co>Cu>V>Ni>Cr,Cr属于清洁级别,Co、Cu、V和Ni处于轻度污染水平,Zn和Pb处于偏中度污染,Cd达到了重污染水平。     

Sub-tropical urban environment affecting content and composition of non-structural carbohydrates of Lolium multiflorum ssp. italicum cv. Lema

This study analyzed the relationship between environmental factors, especially air pollution and climatic conditions, and non-structural carbohydrates (NSC) in plants of Lolium multiflorum exposed during 10 consecutive periods of 28 days at a polluted site (Congonhas) and at a reference site in São Paulo city (Brazil). After exposure, NSC composition and leaf concentrations of Al, Fe, Cu, Zn, Pb and Cd were measured. The seasonal pattern of NSC accumulation was quite similar in both sites, but plants at Congonhas showed higher concentrations of these compounds, especially fructans of low and medium degree of polymerization. Regression analysis showed that NSC in plants growing at the polluted site were explained by variations on temperature and leaf concentration of Fe (positive effect), as well as relative humidity and particulate material (negative effect). NSC in the standardized grass culture, in addition to heavy metal accumulation, may indicate stressing conditions in a sub-tropical polluted environment.     

Experimental exposure to cadmium affects metallothionein-like protein levels but not survival and growth in wolf spiders from polluted and reference populations

Both local adaptation and acclimation in tolerance mechanisms may allow populations to persist under metal pollution. However, both mechanisms are presumed to incur (energetic) costs and to trade-off with other life-history traits. To test this hypothesis, we exposed Pardosa saltans (Lycosidae) spiderlings originating from metal-polluted and unpolluted sites to a controlled cadmium (Cd) treatment, and compared contents of metal-binding metallothionein-like proteins (MTLPs), internal metal concentrations, and individual survival and growth rates with a reference treatment. While increased MTLP concentrations in offspring originating from both polluted and unpolluted populations upon exposure indicates a plastic tolerance mechanism, survival and growth rates remain largely unaffected, independent of the population of origin. However, MTLP and Cd concentrations were not significantly correlated. We suggest that MTLP production may be an important mechanism enabling P. saltans populations to persist in ecosystems polluted with heavy metals above a certain level.     

Heavy metal pollution in China: Origin,pattern and control

GOAL, SCOPE AND BACKGROUND: Heavy metal is among one of the pollutants, which cause severe threats to humans and the environment in China. The aim of the present review is to make information on the source of heavy metal pollution, distribution of heavy metals in the environment, and measures of pollution control accessible internationally, which are mostly published in Chinese. METHODS: Information from scientific journals, university journals and governmental releases are compiled focusing mainly on Cd, Cu, Pb and Zn. Partly Al, As, Cr, Fe, Hg, Mn and Ni a included also in part as well. RESULTS AND DISCUSSION: In soil, the average contents of Cd, Cu, Pb and Zn are 0.097, 22.6, 26.0 and 74.2 mg/kg, respectively. In the water of the Yangtze River Basin, the concentrations of Cd, Cu, Pb and Zn are 0.080, 7.91, 15.7 and 18.7 microg/L, respectively. In reference to human activities, the heavy metal pollution comes from three sources: industrial emission, wastewater and solid waste. The environment such as soil, water and air were polluted by heavy metals in some cases. The contents of Cd, Cu, Pb and Zn even reach 3.16, 99.3, 84.1 and 147 mg/kg, respectively, in the soils of a wastewater irrigation zone. These contaminants pollute drinking water and food, and threaten human health. Some diseases resulting from pollution of geological and environmental origin, were observed with long-term and non-reversible effects. CONCLUSIONS: In China, the geological background level of heavy metal is low, but with the activity of humans, soil, water, air, and plants are polluted by heavy metals in some cases and even affect human health through the food chain. RECOMMENDATIONS AND OUTLOOK: To remediate and improve environmental quality is a long strategy for the polluted area to keep humans and animals healthy. Phytoremediation would be an effective technique to remediate the heavy metal pollutions.     

Occurrence,speciation, and risks of trace metals in soils of greenhouse vegetable production from the vicinity of industrial areas in the Yangtze River Delta,China

The effect of industrial activities on trace metals in farmland of rapidly industrializing regions in developing countries has increasingly been a concern to the public. Here, soils were collected from 13 greenhouse vegetable production (GVP) farms or bases near industrial areas in the Yangtze River Delta of China to investigate the occurrence, speciation, and risks of Cr, Cu, Zn, Cd, Ni, and Pb in GVP soil. The results revealed that the main metal elements causing GVP soil pollution were Cd, Zn, Ni, and Cu, of which contamination levels were generally unpolluted to moderately polluted. Zinc pollution was mainly attributed to heavy fertilization, while Cd, Ni, and Cu pollution may be greatly ascribed to industrial effluents and coal combustion. Metal speciation studies showed that most of Cr, Ni, Cu, and Zn was present in residual fraction while more than half of Cd and Pb was present in non-residual fractions. Additionally, pollution of Cd, Cu, Ni, and Zn in GVP soil increased their corresponding mobile fractions. Risk assessment using potential ecological risk index and risk assessment code showed that Cd was the major risk contributor. Specifically, Cd generally posed moderate or considerable ecological risk as well as displayed medium or high mobility risk in GVP soil. Thus, great attention should be paid to the contribution of both industrial discharges and intensive farming to soil pollution by trace metals, especially Cd, because of its high mobility risk.

     

Risk assessment of heavy metal pollution for detritivores in floodplain soils in the Biesbosch, The Netherlands, taking bioavailability into account

Floodplains of the European rivers Rhine and Meuse are heavily polluted. We investigated the risk of heavy metal pollution (Cd, Cu, Pb, Zn) for detritivores living in a floodplain area, the Biesbosch, the Netherlands, affected by these rivers. Total soil, pore water and 0.01 M CaCl(2) extractable concentrations and concentrations in plant leaves, earthworms, isopods and millipedes were measured in two sites and compared with literature data to assess possible risks. Based on total metal concentrations in soil, serious effects on detritivores were expected. However, 0.01 M CaCl(2) extractable, pore water and plant leaf concentrations were similar to metal concentrations found in unpolluted areas. Concentrations of Cu and Cd in earthworms and Cu in millipedes were higher in the Biesbosch than in animals from reference areas. All other measured concentrations of heavy metals in earthworms, isopods and millipedes were similar to the ones found in reference areas. Despite high total soil concentrations, effects of Zn, Cu, Pb and Cd pollution on isopods are therefore not expected, while millipedes may only be affected by Cu. Since Cu and Cd levels in earthworms were increased compared to animals in unpolluted soils, this faunal group seems to be most at risk. Given the engineering role of earthworms in ecosystems, effects on the ecological functioning of floodplain soils therefore cannot be excluded.     

Effect of submergence-emergence sequence and organic matter or aluminosilicate amendment on metal uptake by woody wetland plant species from contaminated sediments

Site-specific hydrological conditions affect the availability of trace metals for vegetation. In a greenhouse experiment, the effect of submersion on the metal uptake by the wetland plant species Salix cinerea and Populus nigra grown on a contaminated dredged sediment-derived soil and on an uncontaminated soil was evaluated. An upland hydrological regime for the polluted sediment caused elevated Cd concentrations in leaves and cuttings for both species. Emergence and soil oxidation after initial submersion of a polluted sediment resulted in comparable foliar Cd and Zn concentrations for S. cinerea as for the constant upland treatment. The foliar Cd and Zn concentrations were clearly higher than for submerged soils after initial upland conditions. These results point at the importance of submergence-emergence sequence for plant metal availability. The addition of foliar-based organic matter or aluminosilicates to the polluted sediment-derived soil in upland conditions did not decrease Cd and Zn uptake by S. cinerea.     

Effects of soil properties on food web accumulation of heavy metals to the wood mouse (Apodemus sylvaticus)

Effects of soil properties on the accumulation of metals to wood mice (Apodemus sylvaticus) were evaluated at two sites with different pH and organic matter content of the soil. pH and organic matter content significantly affected accumulation of Cd, Cu, Pb and Zn in earthworms and vegetation. For Cd, Cu and Zn these effects propagated through the food web to the wood mouse. Soil-to-kidney ratios differed between sites: Cd: 0.15 versus 3.52, Cu: 0.37 versus 1.30 and Zn: 0.33-0.83. This was confirmed in model calculations for Cd and Zn. Results indicate that total soil concentrations may be unsuitable indicators for risks that metals pose to wildlife. Furthermore, environmental managers may, unintentionally, change soil properties while taking specific environmental measures. In this way they may affect risks of metals to wildlife, even without changes in total soil concentrations.     

Metal accumulation in wild plants surrounding mining wastes

Four sites were selected for collection of plants growing on polluted soil developed on tailings from Ag, Au, and Zn mines at the Zacatecas state in Mexico. Trace element concentrations varied between sites, the most polluted area was at El Bote mine near to Zacatecas city. The ranges of total concentration in soil were as follows: Cd 11-47, Ni 19-26, Pb 232-695, Mn 1132-2400, Cu 134-186 and Zn 116-827 mg kg(-1) air-dried soil weight. All soil samples had concentrations above typical values for non-polluted soils from the same soil types (Cd 0.6+/-0.3, Ni 52+/-4, Pb 41+/-3mg kg(-1)). However, for the majority of samples the DTPA-extractable element concentrations were less than 10% of the total. Some of the wild plants are potentially metal tolerant, because they were able to grow in highly polluted substrates. Plant metal analysis revealed that most species did not translocate metals to their aerial parts, therefore they behave as excluder plants. Polygonum aviculare accumulated Zn (9236 mg kg(-1)) at concentrations near to the criteria for hyperaccumulator plants. Jatropha dioica also accumulated high Zn (6249 mg kg(-1)) concentrations.     

Heavy metal accumulation by poplar in calcareous soil with various degrees of multi-metal contamination: implications for phytoextraction and phytostabilization

The object of this study was to assess the capacity of Populus alba L. var. pyramidalis Bunge for phytoremediation of heavy metals on calcareous soils contaminated with multiple metals. In a pot culture experiment, a multi-metal-contaminated calcareous soil was mixed at different ratios with an uncontaminated, but otherwise similar soil, to establish a gradient of soil metal contamination levels. In a field experiment, poplars with different stand ages (3, 5, and 7 years) were sampled randomly in a wastewater-irrigated field. The concentrations of cadmium (Cd), Cu, lead (Pb), and zinc (Zn) in the poplar tissues and soil were determined. The accumulation of Cd and Zn was greatest in the leaves of P. pyramidalis, while Cu and Pb mainly accumulated in the roots. In the pot experiment, the highest tissue concentrations of Cd (40.76 mg kg^?1), Cu (8.21 mg kg^?1), Pb (41.62 mg kg^?1), and Zn (696 mg kg^?1) were all noted in the multi-metal-contaminated soil. Although extremely high levels of Cd and Zn accumulated in the leaves, phytoextraction using P. pyramidalis may take at least 24 and 16 years for Cd and Zn, respectively. The foliar concentrations of Cu and Pb were always within the normal ranges and were never higher than 8 and 5 mg kg^?1, respectively. The field experiment also revealed that the concentrations of all four metals in the bark were significantly higher than that in the wood. In addition, the tissue metal concentrations, together with the NH₄NO₃-extractable concentrations of metals in the root zone, decreased as the stand age increased. P. pyramidalis is suitable for phytostabilization of calcareous soils contaminated with multiple metals, but collection of the litter fall would be necessary due to the relatively high foliar concentrations of Cd and Zn.     

Assessment of the quality of the air in the city of Palermo through chemical and cell analyses on Pinus needles

The influence of air pollution on the chemical composition of Pinus sp. needles was examined in polluted and control sites in and around the city of Palermo (Sicily). The chemical composition of needles indicated the extent of contamination of the trees, which were cytologically examined. Cell analysis was carried out on pine samples, including needles and pollens, from 15 different locations. Biostructural and spectrophotometric tests were performed. In particular, concentrations of toxic (Cd, Pb) and non-toxic metals (Fe,Cu, Zn) were determined, as well as injury caused by their accumulation in the needles. The more highly urbanised areas showed higher concentrations of metals (Pb, Cu. Zn, Fe); only the concentrations of Cd and Mn turned out to be constant in all the sites. Cell analysis revealed displasic cells and secondary metabolite accumulations in trees from polluted sites. These changes observed were most likely caused by the toxic effect of pollutants.     

Health risk assessment of heavy metal exposure through vegetable consumption around a phosphorus chemical plant in the Kaiyang karst area,southwestern China

The phosphorus chemical industry is an important source of heavy metals in farmland. Vegetables grown on contaminated soil potentially impose adverse effects on human health. In this study, the pollution status and health risks of heavy metals in vegetables around a phosphorus chemical plant in Kaiyang County, Guizhou Province, southwestern China, were assessed, and the low-accumulation vegetables were screened by bioaccumulation factor (BAF) and cluster analysis. Results showed the average concentrations of Hg, As, Cd, Pb, Cr, Mn, Co, and Zn in vegetables were 0.015, 0.728 0.382, 0.227, 0.850, 27.227, 0.525, and 6.438 mg/kg, respectively. The single-factor pollution index showed that Cd was moderately polluted, and Cr, Hg, As, and Pb were slightly polluted. The Nemerow pollution index showed that the overall heavy metal pollution was classified as moderately polluted. The accumulation of heavy metals in different vegetables varied greatly, and chard, crown daisy, chayote, pumpkin, eggplant, white radish, sweet potato, carrot, and potato were selected as the low-accumulator vegetables. The consumption of all vegetables except chayote poses both carcinogenic and noncarcinogenic risks; among them, the consumption of sweet potato leaves has the highest health risks. The local population needs to adjust plantation structure and change dietary habits, and government should strengthen the management of phosphorus chemical plant pollution.

     

Bioconcentration of zinc and cadmium in ectomycorrhizal fungi and associated aspen trees as affected by level of pollution

Concentrations of Zn and Cd were measured in fruitbodies of ectomycorrhizal (ECM) fungi and leaves of co-occurring accumulator aspen. Samples were taken on three metal-polluted sites and one control site. Fungal bioconcentration factors (BCF = fruitbody concentration: soil concentration) were calculated on the basis of total metal concentrations in surface soil horizons (BCF_tot) and NH₄NO₃-extractable metal concentrations in mineral soil (BCF_lab). When plotted on log-log scale, values of BCF decreased linearly with increasing soil metal concentrations. BCF_lab for both Zn and Cd described the data more closely than BCF_tot. Fungal genera differed in ZnBCF but not in CdBCF. The information on differences between fungi with respect to their predominant occurrence in different soil horizons did not improve relations of BCF with soil metal concentrations. Aspen trees accumulated Zn and Cd to similar concentrations as the ECM fungi. Apparently, the fungi did not act as an effective barrier against aspen metal uptake by retaining the metals.     

Heavy metal concentrations in Mullus barbatus and Pagellus erythrinus in relation to body size,gender, and seasonality

Marine environments have been subjected to an increase in heavy metal pollution. Investigations were conducted in the bioaccumulation of heavy metals for both a benthic (Mullus barbatus) and a benthopelagic fish species (Pagellus erythrinus). The aim of this study was to examine the concentration levels of four metals in the body tissue of two fish species, in Pagasitikos Gulf in Greece, and to determine if metal concentration levels were affected by season, size, and species. Fish samples were collected monthly from September 2009 to August 2010. Chromium (Cr), Copper (Cu), Zinc (Zn), and Cadmium (Cd) concentrations were measured in muscle, gills, vertebral column, and in the “remaining fish sample.” Statistical analysis pinpointed substantial differences in metal concentration levels between some size classes. Significant differences were observed between two fish species’ tissues concerning Cu, Zn, and Cd concentrations. Cu and Zn concentrations varied amongst red mullet tissues as did Zn and Cd concentrations in common pandora. Ample variations were found seasonally in metal concentration levels; however, nonsignificant statistical differences were found among sexes.