铅锌冶炼厂渣堆场周边土壤铅污染特征

金属冶炼过程留下的废渣经过雨水冲刷及渗滤液等的作用使残留在废渣中的重金属发生迁移转化,导致渣堆场下及周边土壤受到重金属污染。了解冶炼厂渣堆场下及周边土壤重金属污染状况对场地修复及土地利用规划均有重大意义。本研究调查了湖南某铅锌冶炼厂渣堆场0~4 km内三个采样区0~20 cm表层土壤及0~100 cm深度土壤中铅的污染状况,采用单项污染指数法进行铅污染评价,并分析了铅纵向迁移随深度变化和横向迁移随距离变化的分布特征。结果表明,铅锌冶炼厂渣堆场下及周边0~1 km范围内土壤受到了铅污染,渣堆场下、距渣堆场10 m处及1 km处表层土壤中重金属铅的质量分数分别可达775.25、645.33和309.80 mg·kg^-1,超过了当地土壤中铅的背景值,也超过了土壤二级质量标准甚至三级质量标准。三个采样区的铅污染指数分别为2.6、2.1及1.03,污染等级均为Ⅱ级,污染程度为轻度污染。三个采样区土壤中铅污染主要集中于0~20 cm土壤层中,铅的质量分数分别达775.25,645.33和309.80 mg·kg^-1,20~100 cm土壤层中铅的质量分数低于0~20 cm的,分别在88.48~120.96 mg·kg-1、235.01~380.16 mg·kg^-1及309.80~59.32 mg·kg^-1之间。渣堆场下土壤中的铅从0~20cm土壤层往下至20~100cm土壤层迁移量远小于距渣场10 m处及1 km处的。三个采样区表层0~20 cm土壤层中铅的变化规律为距渣堆场0 m（渣堆场下）〉距渣堆场10 m〉距渣堆场1 km〉距渣堆场4 km,质量分数随距离增加而降低。20~40 cm及40~60 cm土壤层中铅的变化规律为距渣堆场10 m〉距渣堆场1 km〉距渣堆场0 m处（渣堆场下）〉距渣堆场4 km,60~80 cm及80~100 cm土壤层的变化规律为距渣堆场10 m〉距渣堆场0 m处（渣堆场下）〉距渣堆场1 km〉距渣堆场4 km,铅的质量分数随距离的增加先升高后降低。     

Effects of paclobutrazol (PP333) on lead and zinc accumulations in Pseudostellaria maximowicziana

Paclobutrazol (PP333) can enhance the resistance capabilities of plants to stress conditions. In this study, PP333 were sprayed on the lead (Pb) and zinc (Zn) accumulator plant Pseudostellaria maximowicziana, which was planted in Pb–Zn contaminated soil, and the effects of PP333 on Pb and Zn accumulation levels in P. maximowicziana were studied. Spraying 10?mg/L PP333 increased, while 20, 30 and 50?mg/L PP333 decreased, the biomass of P. maximowicziana compared with the control. The 10?mg/L PP333 had no significant effects on the photosynthetic pigment contents of P. maximowicziana compared with the control, while the other doses increased the contents. The activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase) and the Pb and Zn concentrations in P. maximowicziana were increased by PP333 compared with the control. These items had the increase trend with the increase of PP333 concentrations. Only 10 and 20?mg/L PP333 increased the amount of Pb extracted by P. maximowicziana shoots, while all of the doses increased the amount of Zn extracted by P. maximowicziana shoots. Thus, low concentration of PP333 could promote the growth and heavy metal extraction ability of P. maximowicziana shoots, with the 10?mg/L being the best.     

4种草对铅锌尾矿污染土壤重金属的抗性与吸收特性

盆栽试验的结果表明,高羊毛、早熟禾、黑麦草、紫花苜蓿在纯尾矿污染土壤或经处理的尾矿污染土壤上都能生长,但在处理的土壤上生长的植物长势明显优于对照,其中紫花苜蓿的生物量所受影响比其他几种草坪草更大,说明其重金属抗性低于其他几种植物。单位面积上 4 种植物体内重金属质量分数高低均为 w(Zn)>w(Pb)>w(Cu)>w(Cd),但每种植物对 Cd、Pb、Zn 和 Cu 的吸收质量分数和分布均不相同,一般为根系质量分数大于茎叶。加入改良剂(CaCO3)和有机肥(菜枯)使生长在铅锌尾矿污染土壤上的 4 种草坪草生物量显著增加,植物体中的 Cd、Pb、Zn 质量分数下降,但 Cu 质量分数反而上升,结果单位面积上草坪草吸收各重金属元素的量均有所增加,可见利用改良措施与草坪草相结合的方法来修复重金属污染土壤具有可行性。     

Determination of traces of fluorine,chlorine, bromine,cadmium and lead in plastic materials

This paper describes the quantitative determination of F, Cl, Br, Cd and Pb in plastic materials. The concentration of the elements Cl, Br, Cd and Pb is first semiquantitatively measured by X‐ray fluorescence spectrometry (XRF) directly in the solid sample with a detection limit of approximately 10 μg/g. Afterwards, F and any of the other elements which exceed the limit values for materials which are disposable without special precautions are measured after the digestion of the material. The samples are digested either under pressure in an oxygen atmosphere for F, Cl and Br or under pressure with nitric acid for Cd and Pb. The digestion converts the halides to the anions which are measured potentiometrically (F^‐, Br^‐) or with ion chromatography (Cl^‐). Cd and Pb are measured by graphite furnace atomic absorption spectrometry (GF‐AAS). The determination limits achieved are 20 μg/g for F and Br, 250 μg/g for Cl, 0.01 μg/g for Cd and 0.2 μg/g for Pb, all below the limit values set by current regulations in Switzerland.     

干旱区绿洲灌漠土Cu、Zn和Pb的吸附解吸特征

土壤重金属吸附解吸是影响土壤系统中重金属移动性和归宿的主要过程,影响重金属的生物有效性以及重金属在食物链中的传递等.配制一系列不同浓度的重金属,灌漠土对重金属溶液进行吸附实验24 h以达到平衡,再用硝酸铵和乙酸铵进行解吸实验24 h以达到平衡.利用热力学吸附平衡法,对西北干旱区绿洲灌漠土重金属Cu、Ni和Pb的吸附解吸行为进行序批实验研究.实验结果表明:(1)灰漠土在常温下对铜、锌和铅重金属离子的吸附等温线符合Freundlich型吸附模式,灰漠土对重金属铜、锌和铅的吸附能力由强到弱的顺序为:铅,铜,锌.(2)硝酸铵和乙酸铵解吸重金属的量与灰漠土吸附重金属量呈现出线性正相关,乙酸铵解吸重金属的量比硝酸铵解吸重金属的量大,两种解吸剂对铜、锌和铅重金属离子的解吸能力由大到小的顺序都为:铜,锌,铅,说明了一般外源的铜、锌和铅进入土壤以后,铜和锌可能比铅容易向四周转移.(3)硝酸铵和乙酸铵的解吸率呈谷形曲线,开始时硝酸铵和乙酸铵解吸重金属量的百分比随灰漠土吸附重金属量的增加而减小,在吸附量达到某一特定值时,解吸率随吸附量的增加而增加.灰漠土对铜、锌和铅的吸附作用以专性吸附为主,被灰漠土吸附的铜、锌和铅重金属离子较难解吸.     

Hyperaccumulator Thlaspi caerulescens (Ganges ecotype) response to increasing levels of dissolved cadmium and zinc

Hyperaccumulation of metals by plants involves at least three processes: efficient absorption by roots, efficient root-to-shoot translocation and hypertolerance through internal detoxification. In this study, Thlaspi caerulescens was separately exposed to Cd and Zn at 0, 50, 100 and 200 μ M for 7 d to monitor plant responses in hydroponics. Significant dose-dependent accumulation was observed for both metals, mainly in roots (up to 3.2 and 9.2 mg g ^?1 for Cd and Zn, respectively). However, Cd was more phytotoxic in terms of plant growth and photosynthesis. This higher toxicity was also evidenced by MetPLATE bioassay. Root exudation was significantly correlated to Cd and Zn translocation (r>0.85) proving its involvement in facilitating metal uptake. As for antioxidative responses, plants reacted to Cd and Zn by broadly exhibiting an elevation of glutathione reductase activity before declining at 200 μ M due to higher phytotoxicity. By contrast, superoxide dismutase activity was unlikely to be affected by both metals. Root-to-shoot apoplastic flow was traced using a fluorescent dye (trisodium-8-hydroxy-1,3,6-pyrenetrisulfonic acid; PTS), whose concentration in leaves increased to a certain extent with Cd and Zn accumulation, indicating that heavy metals have a comparable effect to drought or salinity in promoting the passive diffusion of water and solutes. Nevertheless, Cd at 200 μ M hindered the diffusion of PTS and consequently affected the apoplastic transport in plants.     

Accumulation of lead and zinc and effects on activities of catalase and GPT in the clam Ruditapes philippinarum A

Acute toxicities of Pb and Zn to clam (if. philippinarum) were determined by a semistatic bioassay. The 96 h LC50 values were 14.28 mg/L for Pb, and 16.40 mg/L for Zn. Exposure of R. philippinarum to various concentration of lead and zinc for a period of 4 days showed that different organs have different capacities for accumulating metals, with high levels in the gill, followed by soft body, and lower amounts in the cavity fluid. Accumulation tests showed that R. philippinarum is a strong accumulator of Pb and weaker accumulator of Zn. The effect of lead on activities of Catalase and GPT were studied in soft body of R. philippinarum. The result showed that the activities of CAT in soft body decreased at all exposure groups, the activities of CAT were negatively correlated with exposure concentration of lead, the special inhibition effect was observed in exposure group of Zn, the CAT activities significantly decreased at lower Zn concentration, then increased slowly with the Zn concentration, finally, decreased to the lowest. The activities of GPT in soft body were significantly increased at high exposure concentrations.     

兰坪铅锌尾矿区豆科植物根瘤菌的多样性及抗性研究

对兰坪铅锌尾矿区自然发生的植物进行调查,共发现18种植物,分属于10科。对野豇豆（Vigna vexiauata（Linn.）Bench.）、长波叶山蚂蝗（Desmodium sequax Wall.）、三叶草（Trifolium pratense Linn.）、白刺花（Sophora davii（franch.）Skeels）、密花序黄芪（Astragalus forrestii Simpson.）、美丽胡枝子（Lespedeza Formosa（Vog.）Koehne.）6种8株豆科植物根瘤进行根瘤菌的分离纯化,共得到419株细菌,经镜检初步确定有94株为根瘤菌。对其中31株根瘤菌的淀粉水解、糖发酵等12项生理生化指标进行测定,并以平均连锁法进行聚类分析。结果表明,兰坪铅锌尾矿区31株根瘤菌在50%的相似水平上可分为6个类群,其表型特性存在明显差异,同一种植物中可能存在不同代谢类型的根瘤菌,同一种代谢类型的根瘤菌也可与不同植物共生。抗逆性测定结果表明,菌株（4G.7、5.4.3、7.4.3）对温度、（4A.12、4G.7、4G.10、5.4.3）对pH、（3.7.9、5.4.3）对盐、（3.7.19、4A.12、6.1.2、6.1.13）对抗生素有较强耐受性或抗性,大多数菌株能在较宽的温度、盐度和pH范围内生长。     

有机酸对根际土壤中铅形态及其生物毒性的影响

采用根袋盆栽试验和连续浸提方法研究外源柠檬酸、EDTA对根际土壤中Pb形态转化及其生物毒性的影响。结果表明，有机酸能明显活化根际土壤中的Pb，高浓度(3mmol／L)比低浓度(0．5mmol／L)的柠檬酸对Pb的活化能力强；EDTA在低浓度(0．5mmol／L)时对Pb的活化能力就很强。柠檬酸、EDTA能增强土壤Pb的毒性，提高小麦根部对Pb的吸收，并促进Pb由根部向地上部转移。     

施用石灰对Pb、Cd、Zn在土壤中的形态及大白菜中累积的影响

重金属的不同形态对于作物吸收重金属及受害具有十分密切的关系,通过施用石灰改变重金属的形态、毒性以及对作物的影响具有重要的意义。以大白菜(Brassica pekinensis)为研究对象,通过盆栽试验,探讨了在铅、镉和锌污染土壤上,施用石灰对土壤中不同形态镉、铅和锌含量及在大白菜中累积的影响。结果表明,施用石灰后,土壤中碳酸盐结合态Pb、Cd和Zn含量明显减少,铁、锰氧化物结合态和有机物结合态Pb、Cd和Zn含量明显增加;对大白菜吸收Pb、Cd和Zn均起到较好的抑制作用,石灰用量为5g·kg-1土时,对大白菜吸收Pb、Cd和Zn的抑制效果最好。     

Effects of salinity on the uptake of lead and cadmium by two mangrove species Rhizophora apiculata Bl. and Avicennia alba Bl.

The uptake of lead (Pb) and cadmium (Cd) by Rhizophora apiculata and Avicennia alba under various salinity levels was examined using hydroponic cultivations. After 3 months of exposure at four levels of Pb (0, 0.03, 0.3 and 3 mg·L^?1) and four levels of Cd (0, 0.005; 0.05 and 0.5 mg·L^?1) at different salinities (0, 15 and 30), uptake of the metals was shown to be differently affected by salinity. For uptake of Pb by R. apiculata, the salinity effect was not significant for the leaves and was most significant in the stem, whereas for A. alba, the effect of salinity was significant only in the stem. Uptake of Pb in the roots and stems of both species was similar, but a higher concentration was recorded in the leaves of A. alba. Salinity was shown to affect the uptake of Cd by all tissues of R. apiculata, but most significantly roots. For A. alba, salinity significantly affects the total uptake of Cd, but this is most significant in the roots. The two mangrove species demonstrated different mechanisms of metal distribution into their organs which may be related to different adaptation mechanisms to saline conditions.     

Uptake of zinc, cadmium and phosphorus by arbuscular mycorrhizal maize (Zea mays L.) from a low available phosphorus calcareous soil spiked with zinc and cadmium

In a multifactorial pot experiment, maize (Zea mays L.) with or without inoculation with the arbuscular mycorrhizal (AM) fungus Glomus mosseae BEG167 was grown in a sterilized soil spiked with three levels of zinc (0, 300 and 900 mg Zn kg⁻¹ soil) and three levels of cadmium (0, 25 and 100 mg Cd kg⁻¹ soil). At harvest after 8 weeks of growth, the proportion of root length of inoculated plants colonized decreased with increasing Zn or Cd additon, and was 56% in the absence of both metals and was reduced significantly to 27% in the presence of the higher levels of both metals. Mycorrhizal plants had higher biomass than non-mycorrhizal controls except at the highest soil level of Cd. Cadmium had more pronounced effects on plant biomass than did Zn at the levels studied and the two metals showed a significant interaction. The data suggest that mycorrhizal inoculation increased plant growth with enchancement of P nutrition, perhaps increasing plant tolerance to Zn and Cd by a dilution effect. AM inoculation also led to higher soil solution pH after harvest, possibly reducing the availability of the metals for plant uptake, and lowered the concentrations of soluble Zn and Cd in the soil solution, perhaps by adsorption onto the extrametrical mycelium.     

Contribution to the ecotoxicological study of cadmium,lead, copper and zinc in the mussel Mytilus edulis

The understanding of natural fluctuations of metal concentrations in mussels used as bio-indicators is indispensable for a good assessment of the disturbances due to pollution. We have studied thoroughly the factors which condition bioaccumulation by using controlled populations of mussels, Mytilus edulis L., sampled monthly over more than two years (March 1982–May 1984) in the Bay of Bourgneuf, France. Seasonal changes in metal levels have been recognized, maximum values being observed in winter and early spring and minimum in later spring and summer. Depending on metal and size group, the ratios between these maximum and minimum values varied between 1.56 and 3.43. The fluctuations in soft-tissue weight appear to be the main explanatory factor of seasonal variations in metal concentrations in mussels. Fluctuations in metal levels related to size of mussels were observed. Except for cadmium in mussels with a mean dry weight of soft tissues >0.2 g, a slight decrease in metal concentrations was observed for growing individuals: the regression coefficient b was -0.10, -0.11, -0.13 and -0.27 for Cd, Cu, Zn and Pb, respectively. The metals examined were rather uniformly distributed among the different groups of organs (visceral mass, gills and palps, remainder) and, consequently, several analyses of metals in different organs do not provide much more information than one analysis on the whole soft tissues. It is concluded that fluctuations related to size or season are reflected by only moderate differences in the maximum and minimum concentrations of metals in the mussels, but that they are nevertheless sufficient to conceal low chronic or short-term pollution, except at those sites where the normal environmental conditions are well-documented.     

Comparative study of plasma lead levels in the staff of Dandy Zinc Factory of Zanjan and in normal individuals

Pollution is a global problem which affects various human population functions. Despite the decline in plasma lead (Pb) levels among the general population during the past 20 years, this metal continues to be a public health concern for individuals with past and present exposures. The objective of this study was to determine blood lead levels (BPbL) in the staff of Dandy Zinc Company and compare them to control subjects. The test group included 40 staff of Dandy Zinc Company of Zanjan, while controls were selected from general population. Five milliliters of blood and plasma was sent to Atomic Energy Organization of Iran (AOEI) reference lab to measure BPbL by Flameless Atomic Absorption. BPbL in test group (16.6 + 8.18 µg dL^?1) was significantly higher than control (10.47 + 2.10 µg dL^?1). In both groups BPbL was significantly higher in smokers than non-smokers. Blood lead levels in molding workers were significantly higher than other workers. BPbL in exposed workers were directly related to duration of work and age. Data indicate Pb exposure was of significant magnitude to be a public health concern especially in zinc-and Pb-related industries.     

Variations between rice cultivars in root secretion of organic acids and the relationship with plant cadmium uptake

To attempt to understand certain mechanisms causing the variations between rice cultivars with regard to Cd uptake and accumulation, pot soil experiments were conducted with two rice cultivars at different levels of Cd, i.e., 0 (the control), 10, 50 mg Cd kg⁻¹ soil. The two rice cultivars differ significantly with regard to Cd uptake and accumulation. Root secretions of low-molecular-weight organic acids (LMWOA) for each treatment were measured with ion chromatography. The results showed that LMWOA concentrations in the soil planted with Shan you 63 (a high soil Cd accumulator) were all higher than those in the soil planted with Wu yun jing 7 (low soil Cd accumulator) at different soil Cd levels, although the magnitudes of the differences varied for individual LMWOA and depend on soil Cd concentrations. For all six LMWOA, there were significant differences at P < 0.05 or < 0.01 levels for soils treated with 10 and 50 mg kg⁻¹ Cd. The magnitude of the differences was greater under soil Cd treatments, especially at relatively low levels (for example, 10 mg Cd kg⁻¹ soil), than in the control. Acetic acid and formic acid constituted more than 96% of the total concentration of the six LMWOA, while citric acid constituted only about 0.1%. The rice cultivar with higher concentrations of LMWOA in soil accumulated more Cd in the plants. The results indicate that LMWOA secretion by rice root, especially in Cd-contaminated soils, is likely to be one of the mechanisms determining the plant Cd uptake properties of rice cultivars.     

硅对镉、锌、铅复合污染土壤中黑麦草生理生化性质的影响

采用正交试验设计L9(34)对黑麦草(Lolium perenne L.)进行温室盆栽试验,观测Cd、Zn、Pb复合污染条件下,硅(Si)对黑麦草生物量、叶绿素含量以及保护酶系统的影响.结果表明,Cd使黑麦草根系发育受阻导致生物量下降,中等水平的Zn和Pb有利于黑麦草生物量的积累;Cd、Zn、Pb复合污染造成黑麦草叶绿体结构的破坏,使叶绿素含量减少;低水平的Cd、Zn、Pb复合污染对黑麦草CAT和POD活性起到激发作用,但随着添加水平提高,两种酶活性受到抑制.Si可以促进黑麦草根系生物量的增加,有利于根系对水分和养分的吸收,保证地上部分的养分供给,使叶片生物量增加;硅化细胞的形成有利于黑麦草叶片对光能的吸收利用,Si也使叶绿素含量增加;Si对CAT和POD有显著激活作用,从而减轻重金属复合污染对黑麦草产生的伤害.     

Acute and chronic toxic effect of lead (Pb) and zinc (Zn) on biomarker response in post larvae of Penaeus monodon (Fabricus, 1798)

Metal pollution produces damage to marine organisms at the cellular level possibly leading to ecological imbalance. The present investigation focused on the acute and chronic toxicity of lead (Pb) and zinc (Zn) by examining the effects of biomarker enzymes in post-larvae of Penaeus monodon (Tiger prawn). Antioxidant biomarker responses such as lipid peroxidation (LPO) and catalase (CAT) activity for Pb and Zn were determined following chronic exposure. Acute Lethal Concentration ₅₀ (LC₅₀) values observed in the study at 96?h for Pb and Zn at 5.77?±?0.32?mg?L^?1 and 3.02?±?0.82?mg?L^?1, respectively. The estimated No Observed Effect Concentration and Lowest Observed Effect Concentration values for Pb were 0.014 and 0.029?mg?L^?1 and that recorded for Zn was 0.011 and 0.022?mg?L^?1, respectively. Among the two metals studied, toxicity of Zn was found to be greater to P. monodon than Pb. The activities of antioxidant defense enzymes and total protein content differed significantly from control following exposure to both metals. Overall, the biomarker studies demonstrated that alterations in antioxidant enzymes and induction of LPO reflect the consequences of heavy metal exposure in P. monodon.     

Antioxidant role of ascorbic acid on oxidative stress induced by sub-acute exposure of lead and cypermethrin in erythrocytes of Wistar rats

This study aimed to evaluate the reparative potential of ascorbic acid (AA, 100 mg/kg, orally for 28 days) in sub-acute lead (Pb, 100 ppm in drinking water for 28 days) or cypermethrin (CPM, 50 mg/kg, orally in vehicle for 28 days) poisoning alone and as binary mixture on the basis of oxidative stress parameters in erythrocytes of Wistar rats. Both Pb and CPM produced significant increase in lipid peroxidation along with elevated glutathione-S-transferase and catalase activity individually but not as a binary mixture. Glutathione peroxidase activity was significantly increased but glutathione levels were significantly reduced irrespective of single or co-exposure while the activity of superoxide dismutase and erythrocytic protein content were not significantly affected. Co-exposure led to a comparatively lower level of oxidative stress than that induced by Pb or CPM alone indicating an antagonistic toxicodynamic profile in rat erythrocytes. Co-administration of AA along with Pb and/or CPM significantly restored the oxidative stress parameters to normal values. Overall results indicated that co-exposure induces a lower level of oxidative stress and AA ameliorates Pb- and/or CPM-induced oxidative damage in rat erythrocytes.     

The effects of exposure to zinc and cadmium separately and jointly on the free amino acid pool of Gammarus pulex (L.)

Effects of the heavy metals zinc and cadmium on the free amino acid (FAA) pool of Gammarus pulex were studied at different metal concentrations and combinations as well as different exposure times. The dominant effect of these two metals was the reduction of most free amino acids and the whole FAA pool, except in the 10‐day low zinc and cadmium concentration exposures which resulted in a rise of free amino acid pool.

Among the free amino acids, the most sensitive to zinc exposure, were alanine, glutamic acid, arginine, and taurine; valine, leucine, asparagine, and isoleucine were among the most sensitive to cadmium. No predictable changes of individual free amino acids were shown in the mixed metals exposures. Elevation of taurine concentration was constant in seven of the eight treatments, it is suggested that this elevation may be related to the hepatopancreatic damage observed and induced synthesis of metallothioneins.     

Lead, Zinc, Copper, and Cadmium in Fish and Sediments from the Big River and Flat River Creek of Missouri's Old Lead Belt

The Old Lead Belt of Missouri was a major lead-producing region for over a century. Several large tailings piles and other industrial wastes remain behind, though mining operations in the region ceased in 1972. Samples of stream sediments and fish were collected from established sites on the Big River and Flat River Creek over a 3-year period from 1998 to 2000 to evaluate ongoing remediation efforts and determine the current impact of residual mining wastes. Benthic sediments and fish taken in the vicinity of inactive industrial sites were found to contain elevated concentrations of Pb, Zn, Cu, and Cd. Concentrations of Pb and Zn in fillets of suckers and sunfish, as well as in whole bodies of sunfish, correlate well with metal concentrations observed in surficial sediments. The results of analyses provide valuable quantitative information regarding specific sources, current levels of contamination, potential risk to public health, and will allow more accurate assessment of continuing remediation efforts.