Hyperaccumulation of Pb, Zn and Cd in herbaceous grown on lead-zinc mining area in Yunnan, China

A field survey of herbaceous growing on lead-zinc mining area in Yunnan, China were conducted to identify species accumulating exceptionally large concentrations of Pb, Zn and Cd in shoots. In total, 220 plant samples of 129 species of 50 families and 220 soil samples in which the plants were growing were collected. According to accumulation concentration in plant shoots and the concentration time levels compared to plants from non-polluted environments, 21 plant samples of 16 species were chosen as best-performing specimens, 11 plant samples of 10 species for Pb, 5 plant samples of 4 species for Zn and 5 plant samples of 5 species for Cd. Sonchus asper (L.) Hill in Qilinkeng had hyperaccumulation capacity to Pb and Zn. Corydalis pterygopetala Franch in Paomaping had hyperaccumulation capacity to Zn and Cd. All 5 Cd hyperaccumulators came from Lanping lead-zinc mining area. Out of 11 Pb hyperaccumulators, 7 came from Minbingying of Huice lead-zinc mining area. The average of the concentration time levels compared to plants from non-polluted environments were higher than 10 times in all plant samples, the concentration time levels changed from 203 times to 620 times for Pb, from 50 times to 70 times for Zn and from 145 times to 330 times for Cd. Out of 21 plant samples, translocation factor changed from 0.35 to 1.90, only translocation factor of 7 plant samples were higher than 1. Enrichment coefficients of all samples were lower than 1. These plant species were primarily heavy metal hyperaccumulator, and will be used in phytoremediation of the metallic pollutants in soils after further research in accumulation mechanism.     

长三角典型城郊农田土壤-浙贝母重金属迁移特征研究

城郊生态系统中土壤重金属分布及其在土壤—植物系统的迁移和富集特征是城乡共生体土壤安全研究的热点问题。以典型经济作物浙贝母(Fritillaria thunbergii)为例,基于野外采样和实验分析,对长三角代表性城郊农田中土壤—植物系统重金属的分布、富集和迁移特征开展研究。结果表明:受人类活动的影响,城郊农田土壤中重金属除Cr外,Cu、Zn、As、Cd和Pb的平均含量超过土壤背景值,并且不同重金属在空间分布上表现较高的空间异质性。除Cd和Cr外,浙贝母植株不同部位重金属含量表现为叶、茎显著高于鳞茎,叶中重金属含量可达到鳞茎的5～10倍,表明叶比鳞茎更易富集重金属。重金属迁移系数分析表明,Cr、Cu、Zn、As、Cd和Pb主要富集在浙贝母植株的地上部分,且不同重金属在植株中的迁移和富集能力具有较大的差异。浙贝母地上部分对Cr、As和Pb的富集能力较低,对Cu、Zn和Cd的富集能力相对较强。相比而言,鳞茎对不同重金属的富集能力均较弱,综合污染评价也表明,浙贝母鳞茎中重金属含量并未超过污染标准。     

鄱阳湖水土环境及其水生维管束植物重金属污染

位于鄱阳湖流域乐安河中下游的德兴铜矿,是我国著名的大型铜业基地,是鄱阳湖流域重金属污染的主要来源之一。2003年7月至8月对鄱阳湖部分流域的水质、沉积物、底泥及水生维管束植物等样品的重金属污染进行了研究调查,采用原子吸收分光光度法分别对样品中的Cu、Zn、Pb、Cd等重金属含量进行了测定,并对测定结果进行了评价。研究结果表明,鄱阳湖流域水体中的重金属含量均达到地表水评价标准中的Ⅰ类标准,底泥、土壤等已受到了一定程度的重金属污染。而水生植物对重金属元素都具有不同程度的富集能力,植物对重金属的富集作用与土壤背景值有一定的相关性,土壤中重金属的背景值越高,植物对重金属的富集量也相应增加。     

Impacts of sewage irrigation on heavy metal distribution and contamination in Beijing, China

A potential hazard to Beijing was revealed due to the accumulation trend of heavy metals in agricultural soils with sewage irrigation, which results in metal contamination and human exposure risk. Samples including soils and plants were collected to assess the impacts of sewage irrigation on the irrigated farming area of Beijing. Concentrations of the five elements Cd, Cr, Cu, Zn, and Pb were determined in samples to calculate the accumulation factor and to establish a basis for environmental protection and the suitability of sewage irrigation for particular land use in the urban-rural interaction area of Beijing. Using reference values provided by the Beijing Background Research Cooperative Group in the 1970s, the pollution load index (PLI), enrichment factor (EF), and contamination factor (CF) of these metals were calculated. The pollution load indices (sewage irrigation land 3.49) of soils indicated that metal contamination occurred in these sites. The metal enrichment (EF of Cd 1.8, Cr 1.7, Cu 2.3, Zn 2.0, Pb 1.9) and the metal contamination (CF of Cd 2.6, Cr 1.5, Cu 2.0, Zn 1.7, Pb 1.6) showed that the accumulation trend of the five toxic metals increased during the sewage irrigation as compared with the lower reference values than other region in China and world average, and that pollution with Cd, Cu, Zn, and Pb was exacerbated in soils. The distributions of these metals were homogeneous in the irrigation area, but small-scale heterogeneous spatial distribution was observed. Irrigation sources were found to affect heavy metal distributions in soils. It was suggested that heavy metal transfer from soils to plants was a key pathway to human health exposure to metal contamination. However, with the expansion of urban areas in Beijing, soil inhalation and ingestion may become important pathways of human exposure to metal contamination.     

Environmental contamination of heavy metals from zinc smelting areas in Hezhang County, western Guizhou, China

Total heavy metal (Cd, Cr, Cu, Pb and Zn) concentrations were evaluated in smelting waste, soil, crop and moss samples collected from the Hezhang artisanal zinc smelting areas, Guizhou, China. Soil samples from the cornfield near the smelting sites contained extremely high Cd (5.8-74 mg kg(-1)), Pb (60-14,000 mg kg(-1)) and Zn (260-16,000 mg kg(-1)) concentrations. Elevated heavy metal concentrations were also found in corn plants and total Pb (0.80-1.5 mg kg(-1)) and Cd (0.05-0.76 mg kg(-1)) concentrations in corn grain have totally or partially exceeded the national guidance limits for foodstuff. Thus, the soil-to-crop transfer of heavy metals might pose a potential health risk to the local residents. Similar to the high heavy metal levels in soil and corn, Cd, Cr, Cu, Pb and Zn concentrations in moss samples collected from the smelting sites ranged from 10 to 110, 10 to 55, 26 to 51, 400 to 1200 and 330 to 1100 mg kg(-1), respectively, exhibiting a local spatial pattern of metals deposition from the atmosphere. Based on examination of Zn/Cd and Pb/Cd ratios of the analyzed samples, we have distinguished between the flue gas dust derived and smelting waste derived metals in different environmental compartments.     

Chemical pollution: Transfer of chemical elements to the aboverground phytomass of herbaceous plants

Changes in the species composition and a decrease in species diversity and total plant biomass along the gradient of soil pollution with heavy metals have been shown. Data on the concentrations of chemical elements (Zn, Cu, Cd, Pb, Co, Ni, Mn, Cr, and Fe) in the aboveground organs of herbaceous plants and the biomass of each species make it possible to estimate the role of higher producers in the incorporation of chemical elements into biogenic cycles in background zones and under conditions of chemical pollution. Plants of the composite family (Asteraceae) play the main role in accumulation of chemical elements. The results obtained indicate that natural ecosystems have mechanisms limiting excessive accumulation of chemical elements into the aboveground plant biomass.     

Heavy metals in water, sediments, plants and fish of Kali Nadi U.P. (India)

The distribution of heavy metals viz., Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in the water, sediments, plants and fish samples collected from the Kali Nadi (India) have been determined. The studies have shown that there was considerable variation in the concentration of heavy metals from one sampling station to the other which may be due to the variation in the quality of industrial and sewage wastes being added to the river at different places. The orders of the concentration of heavy metals in water, sediments, plants (Eicchornia crassipes) and fish (Heteropnuestes fossilis) were Fe > Zn > Cu > Mn > Cr > Ni > Pb > Co > Cd; Fe > Zn > Mn > Ni > Cr > Co > Cu > Pb > Cd; Fe > Mn > Zn > Cu > Ni > Co > Pb > Cr > Cd and Fe > Zn > Mn > Ni > Pb > Co > Cr > Cu > Cd, respectively.     

Heavy metals in organisms and sediments from Turkish Coast of the Black Sea, 1997-1998

During the period 1997-1998, macroalgae, sea snail, mussel, fish and sediment samples were collected at different stations of the Turkish Black Sea coast in order to establish the concentration of selected heavy metals. Heavy metals analyzed were Cd, Co, Cr, Ni, Zn, Fe, Mn, Pb and Cu. The results showed that the Turkish Black Sea coast is facing heavy metal pollution. The metal concentrations in macroalgae, sea snail, mussel and sediment samples are very high. However, Cd, Pb and Cu concentrations in anchovy fish decreased, while Co, Fe, Zn, Cr, Mn and Ni contents had changed when compared previous data. The metal levels in macroalgae did not follow the same pattern as concentrations in sediments at the same station. On the other hand, concentrations of Cd, Co, Cr, Zn, Fe, Mn and Cu in sea snail, mussel and fish samples were related to sediment data in the examined stations.     

Long-term dynamics of heavy metal concentrations in the food and liver of bank voles (<Emphasis Type="Italic">Myodes glareolus</Emphasis>) in the period of reduction of emissions from a copper smelter

Long-term changes in the contents of heavy metals (Cu, Zn, Cd, Рb) in the food and liver of bank voles (Myodes glareolus) inhabiting areas exposed to pollution from the Middle Ural Copper Smelter (MUCS) in the period of reduction of its emissions (1990–2015). The results show that 50-fold reduction of emissions has not resulted in an equivalent decrease in the dietary and body concentrations of metals: in the impact zone (1–2 km from the MUCS), Cu, Zn, and Pb concentrations remain unchanged, while Cd concentrations have increased twofold by the end of the observation period; in the background zone (20 km), Cu, Zn, and Cd concentrations remain unchanged, while Pb concentrations have decreased by a factor of 1.7–2.5; and no directed changes have been revealed in moderately polluted plots (4–6 km). The accumulation of heavy metals in the animal body depends primarily on the contents of these elements in food and on the system of elementspecific homeostatic barriers providing effective protection from the toxic effect of heavy metals.     

鄱阳湖主要入湖口重金属的分布及潜在风险评价

于2011年5月在鄱阳湖的主要入湖口采集了水样和表层沉积物,测定并分析了其中Cu、Zn、Pb、Cd 4种重金属元素的含量和分布。同时采用地积累指数法、潜在生态危害指数法和生态毒性效应等评价方法对沉积物中重金属的污染状况进行了分析评价。结果显示：鄱阳湖主要入湖口水体重金属Cu、Zn、Pb、Cd含量均符合国家渔业水质标准要求,除修河的Pb和信江、饶河入湖口的Cd含量属于国家地表水Ⅱ类水质外,其它所有样地的4种重金属含量均低于国家地表水I类标准限值。沉积物中4种重金属含量均超过鄱阳湖相应背景值且呈积累富集的趋势,其中信江入湖口、饶河入湖口以及三江口已受到重金属的严重污染,潜在生态危害均为中等,而污染最轻的区域为南主湖区。揭示重金属污染程度顺序为Cu＞Zn＞Pb＞Cd;单个重金属潜在生态风险顺序为Cd＞Cu＞Pb＞Zn。进一步的生态毒性效应评价结果表明,虽然鄱阳湖主要入湖口沉积物已经受到重金属污染,但对多数底栖生物未产生明显毒害     

滴水湖沉积物中重金属污染特征与评价

分析滴水湖及其周边沉积物中Hg、As、Cu、Cd、Pb、Zn和Cr等7种重金属含量特征,并用地累积指数法、潜在生态风险指数法和主成分分析法对沉积物中的重金属污染状况进行了评价和分析。结果表明,滴水湖沉积物中As和Pb低于上海市潮滩背景值,Hg、Cd、Zn和Cr均高于潮滩背景值,50%样点的Cu高于潮滩背景值;地累积指数法评价结果表明滴水湖沉积物中Cr的平均污染水平为偏中污染,Hg、Cd和Zn为轻度污染,As、Cu和Pb为清洁水平;潜在生态风险指数法评价结果表明滴水湖沉积物重金属为中等生态风险,Hg和Cd是潜在生态风险的主要贡献元素;主成分分析结果表明,滴水湖沉积物中Hg、Cu、Cd、Pb、Zn和Cr主要来自于人为源,As主要来自底质滩涂     

长江口洋山海域表层沉积物重金属的富积及其潜在生态风险评价

根据长江口洋山海域表层沉积物监测资料，利用变异系数法和富积系数法，对表层沉积物中重金属的空间波动程度及富积程度进行了分析，并采用Hakanson潜在生态危害指数法对其潜在生态危害程度进行了评价。结果表明：在表层沉积物所监测的重金属中，Pb元素的空间波动程度最高，其它重金属元素的空间波动程度较低，各重金属空间波动程度的顺序依次为Pb＞Cd＞Hg＞Cu＞Cr＞As＞Zn；沉积物中Cu元素的富积程度最高，Pb元素次之，其它重金属元素的富积程度较低，各重金属富积程度的顺序依次为Cu＞Pb＞Zn＞As＞Cr＞Cd＞Hg。潜在生态危害评价结果显示：洋山海域表层沉积物中的重金属对海洋生态系统的潜在生态危害较轻微，均属于轻微潜在生态危害程度，其轻微潜在生态危害程度顺序为Cu＞As＞Hg＞Pb＞Cd＞Cr＞Zn。     

Metal concentrations in mussel Crenomytilus grayanus and oyster Crassostrea gigas in relation to contamination of ambient sediments

The relationship between Zn, Cu, Cd, Pb, and Ni concentrations in soft tissues of mussels and oysters and those in ambient sediments was examined. The study area was the coastal habitats of the northwestern Sea of Japan, which has a broad range of contamination due to urban sewage. Significant increases of all metals, except Ni, were observed in mussel Crenomytilus grayanus at concentrations of easily leachable metals in ambient sediments higher than 2, 100, and 800 microg/g for Cd, Cu, and Zn, respectively. Pb was accumulated by the mussels with no distinct threshold in Pb contamination of sediments. After 2 months, C. grayanus transplanted from a pristine to a contaminated locality increased in Pb up to 12%, and Cu up to 68% of concentrations of these metals in the contaminated local mussels, but Zn and Cd concentrations increased only in the excretory tissue, not in the somatic tissue, or in the soft tissue as a whole. Such regulation of metal accumulation puts limitations on the use of C. grayanus for monitoring of slightly and moderately contaminated localities. On the other hand, the oyster Crassostrea gigas showed definite accumulation of all metals, except Ni, at moderate contamination of ambient sediments. As contamination of sediments increased, increases of Pb, Zn and Cu concentrations in C. gigas slowed, possibly due to physiological control at very high metal concentrations in oyster soft tissue. Thus, the mussel C. grayanus should be used mainly for the monitoring of heavy contaminated localities, and the oyster C. gigas is more suitable as an indicator of low and moderate contamination.     

Correlations between speciation of Cd,Cu, Pb And Zn in sediment and their concentrations in total soft tissue of green-lipped mussel Perna viridis from the west coast of Peninsular Malaysia

Total concentrations and speciation of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) in surface sediment samples were correlated with the respective metal measured in the total soft tissue of the green-lipped mussel Perna viridis, collected from water off the west coast of Peninsular Malaysia. The aim of this study is to relate the possible differences in the accumulation patterns of the heavy metals in P. viridis to those in the surface sediment. The sequential extraction technique was employed to fractionate the sediment into 'freely leachable and exchangeable' (EFLE), 'acid-reducible,' 'oxidisable-organic' and 'resistant' fractions. The results showed that significant (P<.05) correlations were observed between Cd in P. viridis and Cd in the sediment (EFLE fraction and total Cd), Cu in P viridis and Cu in the sediment (EFLE and 'acid-reducible' fractions and total Cu) and Pb in P viridis and Pb in the sediment ('oxidisable-organic' fraction and total Pb). No significant correlation (P > .05) was found between Zn in P viridis and all the sediment geochemical fractions of Zn and total Zn in the sediment. This indicated that Zn was possibly regulated from the soft tissue of P. viridis. The present results supported the use of P viridis as a suitable biomonitoring agent for Cd, Cu and Pb.     

基于年轮年代学重建青藏高原东缘百年来重金属污染历史

采用年轮化学分析方法,测定了青藏高原东缘贡嘎山东坡峨眉冷杉(Abiesfabri)年轮中8种重金属元素(Pb、Cd、Cr、Mn、Cu、Zn、Sr和As)含量,分析了过去150年间重金属元素含量的变化特征,并探讨了重金属元素的可能来源.结果表明:Mn、Cu、Zn作为植物生长发育的必需元素,其含量显著大于其余5种重金属,8种重金属元素中,除Mn、Cu含量变化趋势较为单一之外,其余6种重金属含量均表现出复杂的变化趋势;相关分析和聚类分析显示,树轮中Cr、Sr、Pb、As为一类,主要受到人为源和自然源的综合影响;Mn、Zn、Cd为一类,主要受到人为污染源的影响;Cu元素单独归类,很大程度上来自于地壳源.青藏高原东缘地区树轮中重金属含量相对较低,但是随着工业生产活动增加,该地区重金属污染状况已有所增加,通过对该地区树轮中重金属含量的分析,有利于重建该地区重金属污染历史.     

Partitioning of metals in sediments from the Odiel River (Spain)

The Odiel River runs through an area known as the Iberian pyrite belt in the province of Huelva in the southwestern corner of the Iberian Peninsula. Its waters are acidic and contain large amounts of heavy metals from erosion and mining activity. In addition, the Odiel River estuary is one of the most industrialized areas in southern Spain and, consequently, receives the discharge of industrial and urban waste. Seventeen sediment samples from the Odiel and its main tributaries were analyzed for this study. The chemical partitioning of metals (Cu, Zn, Cd, Pb, Fe, Ni, Cr and Co) in each sample was determined in four fractions (acid-soluble, reducible, oxidizable and residual). The total content of each of the metals was also determined. The results showed high concentrations of Fe, Cu, Zn, Pb and Cd, undoubtedly as a result of contamination from the mining and industrial activity mentioned above. However, the concentrations of the other metals analyzed were low since there are no sources of pollution by them in the Odiel River. Based on the chemical distribution of metals, we found that Cd, Zn and Cu are the most mobile metals (i.e., metals that can pass easily into the water under changing environmental conditions). Cd is the metal that showed the highest percentages in the acid-soluble fraction (the most labile) and the lowest in the residual fraction. However, Pb, Fe, Cr and Ni are present in the greatest percentages in the residual fraction, which implies that these metals are strongly linked to the sediments.     

Distribution of heavy metals in sediments of Mwanza Gulf of Lake Victoria,Tanzania

Sediment samples were analyzed for Cd, Cr, Cu, Pb, Hg and Zn by AAS. The highest concentrations (ppm) for Cu (26.1+/-4.8), Hg (0.2+/-0.05), Pb (30.7+/-5.6) and Zn (45.4+/-13.1) were found at approximately 25 m from the shoreline. Generally, heavy metals concentration in the sediment decreased with increasing distance from the shoreline except for Cd and Cr whose highest concentrations were found at approximately 2000 m from the shoreline.The data also indicated that sediment samples which were collected at the shores within the urban area of Mwanza showed elevated levels of Pb (54.6+/-11.1 ppm) and Zn (83.7+/-21.5 ppm). However, the highest concentrations of Cd (7.0+/-2.1 ppm), Cr (12. 9+/-1.0 ppm) and Hg (2.8+/-0.8 ppm) were recorded at sampling stations which were adjacent to river mouths.     

Levels of "toxic" and "essential" metals in samples of bovine milk from various dairy farms in Calabria, Italy

The aim of this research was to evaluate the possible contamination by heavy metals of milk from cows bred on various farms in Calabria. The concentrations of heavy metals were determined in 40 samples of bovine milk from the various dairy farms. Each sample, homogenized and powdered, was mineralized in a microwave oven. Quantitative analyses of Cd, Cr, Cu, Pb and Se were performed using an atomic absorption spectrophotometer with graphite furnace; As was analyzed by hot vapor generation technique and Zn with the flame method. As regards toxic heavy metals, highest values are those of As (g.m. 37.90 microg/kg w.w.) and Pb (g.m. 1.32 microg/kg w.w.), while lowest concentrations are those of Cd (g.m. 0.02 microg/kg w.w). With regard to essential metals, Zn (g.m. 2016 microg/kg w.w) and Se (g.m. 13.24 microg/kg w.w.) showed the highest concentrations, followed by Cr (g.m. 2.03 microg/kg w.w.) and Cu (g.m. 1.98 microg/kg w.w.). Further investigations of the levels of heavy metals (As) in a greater number of milk samples from various zones of Calabria are necessary, both to examine this problem from the clinical epidemiological point of view and to identify the possible causes of milk contamination.     

Fractionation studies and bioaccumulation of sediment-bound heavy metals in Kolleru lake by edible fish

Kolleru lake is the largest fresh water lake in the districts of East and West Godavari of Andhra Pradesh, India. Many anthropogenic sources contribute to the heavy metal pollution in the lake and the bioaccumulation of heavy metals in fish helps in assessing the aquatic pollution. Total contents and fractionation of selected heavy metals, viz., Zn, Cu, Cd, Pb, Cr, Ni and Co were measured in sediment sample and three edible fish. The investigation aimed at revealing differences in the accumulation pattern of heavy metals in fish inhabiting sediments characterized by varying metal bioavailability. The metal concentrations were found to be greater than the background concentrations of sediments indicating the anthropogenic origin of metals. Good recovery values were obtained for metal contents in sediments and fish. Large fractions of Zn, Cd and Cu were associated with mobile fraction of sediment and showed greater bioaccumulation in fish whereas Ni and Co were least mobilisable. The results clearly indicate that the fish of Kolleru lake are contaminated with metals and not advisable for human consumption.     

The interaction of heavy metals with urban soils: sorption behaviour of Cd, Cu, Cr, Pb and Zn with a typical mixed brownfield deposit

This study investigated the sorption characteristics and release of selected heavy metals (Cd, Cu, Cr, Pb and Zn) from a typical urban soil material from a derelict brownfield site in Western Scotland, UK. The study aimed to evaluate contaminant interactions with an urban substrate, comprising a mix of mineral soil and residue materials (e.g. brick, concrete, wood). This type of material has received little consideration in the literature to date. Soil samples were subject to a sequence of test involving batch equilibration and dynamic leaching, in single (non-competitive) and multi-element (competitive) solutions. The batch experiments were carried out in unadjusted and close to soil field pH conditions (pH 2 and 7, respectively). The equilibrium adsorption capacity for heavy metals was measured and extrapolated using the Langmuir isotherm. The parameters of the isotherms x(m) (the maximum amount adsorbed per unit mass of adsorbent (mg/g)) and b (adsorption constant (m(3)/g)) were calculated for Cd, Cu, Cr, Pb as single-element and multi-element solutions. The adsorption from the single-element solution was more effective than adsorption under multi-element conditions, due to competitive effects. For example, the adsorption of copper from a single-element solution was over four times greater than for a multi-element solution. In the case of Cr and Zn, migration of metal from soil to solution was observed. Adsorption capacity at pH 2 followed the order Cr>Cu>Pb>Cd and at pH 7 Cd>Zn, with precipitation affecting Cu and Pb behaviour. During the column leaching experiment, most of the heavy metals were irreversibly bound to the soil, but in the case of Cr some movement from soil into solution was observed. The results also showed that Cd, Cu, Pb and Zn were removed from the solution and adsorbed on the soil. No significant difference in the metal removal from single- and multi-element solutions was observed. Overall, the urban residue behaved in a similar manner to mineral soils despite a significant component of anthropogenic solid materials.