Cumulative Title Index

Abstract

Metal fractionation is a powerful tool for studying the mobility, bioavailability and toxicity of metals in sediments and soils. A seven-step sequential extraction technique was used to determine the potential mobility of selected heavy metals (Fe, Mn, Zn, Cu, Pb, Cd and Ni) in the sediments of Lake Naivasha. Results indicate that residual fraction was the most important phase for the elements Fe, Mn, Cu and Zn. However, Pb and Cd are highly enriched in the non-residual phases. Nickel on the other hand was distributed evenly between the non-residual and the residual fractions.

The total concentrations of the heavy metals suggested a decreasing order of iron ?> manganese ? zinc > nickel > copper ? lead > cadmium. However, the detailed sequential extraction data indicated an order of release or mobility of cadmium > lead ? nickel ? zinc > manganese > copper > iron. The high percentage of Cd and Pb in the mobile fractions suggests high bioavailability of these two elements in the study area and maybe a pointer to anthropogenic input of the two elements in the study area.     

行道树毛白杨树干中重金属元素分布

采用电感耦合等离子体发射光谱法(ICP),测定分析首都机场高速公路旁毛白杨(Populus tomentosa Carr.)树干中Pb、Cd、Cr、Cu、Zn、Ni和Mn 7种重金属元素的含量及积累量,比较分析树干不同组织、不同方位、不同龄级年轮重金属含量差异及与交通量、关键气候因子的相关性。结果表明:树干木质部中各重金属平均含量由大到小依次为Zn、Cu、Cr、Mn、Ni、Pb、Cd,树皮中依次为Zn、Mn、Cr、Pb、Cu、Cd、Ni,树皮中各重金属元素的含量明显高于木质部;同一树干木质部中,各重金属元素在不同方位的分布有所差异,其中,靠近车道一侧的各重金属元素含量均高于背离车道一侧,南北向比较中,Ni、Zn为南侧含量高于北侧,其他5种重金属元素均为北侧高于南侧;以5a为一个龄级将年轮划分为5个龄组,各龄级年轮中重金属含量随时间的变化趋势各异,其中Pb、Cd、Cu、Zn总体呈递减趋势,且与年降水量、最低气温、日照时数、雨天日数和大风日数呈正相关趋势,与年平均气温和最高气温呈负相关趋势;各元素在毛白杨树干木质部中的积累量表现为ZnCrCuMnPbNiCd。     

表面活性剂对长柔毛委陵菜(Potentilla griffithii var. velutina)修复重金属污染的促进作用

研究了十二烷基苯磺酸钠(SDBS)、十六烷基三甲基溴化铵(CTAB)、聚乙二醇辛基苯基醚(TritonX-100)等不同离子类型的表面活性剂对水稻土中重金属的解吸效果,并采用盆栽实验研究了上述3种表面活性剂对Zn超富集植物长柔毛委陵菜(Potentilla griffithii var. velutina)的生物量、吸收和富集重金属的影响.结果表明:CTAB对水稻土中Zn、Pb、Cd和Cu的解吸效果好于SDBS和TritonX-100,而且3种表面活性剂对各重金属的解吸率大小都为Cd>Zn>Cu>Pb.3种表面活性剂促进长柔毛委陵菜叶、柄和根的生物量增加了0.2～2.5倍,并且长柔毛委陵菜各部位的生物量大小为叶>柄>根.3种表面活性剂都增加了长柔毛委陵菜各部位对Zn、Cd吸收及其叶和柄对Pb、Cu的吸收,同时显著促进Zn、Pb、Cd和Cu从植物根部向地上部转运,从而增加了Zn、Pb、Cd和Cu在长柔毛委陵菜地上部的提取量和分布以及长柔毛委陵菜对Zn、Pb、Cd和Cu的富集能力;因此3种表面活性剂都提高了长柔毛委陵菜修复重金属污染土壤的效率.     

The Effect of Electrolyte Type and Concentration on the Release of Cd,Cu, Ni,and Zn in Some Contaminated Calcareous Soils

This paper reports the results of desorption experiments of cadmium (Cd), copper (Cu), nickel (Ni), and zinc (Zn) from some contaminated calcareous soils under four electrolyte types (CaCl₂, MgCl₂, NaCl and Na₂SO₄) with different electrolyte concentrations (0.5, 4 and 10 mM). Among electrolytes, CaCl₂ significantly released more metals from soils. There was a negative relationship between total Cu and Zn content and percentage of Cu and Zn released (average of electrolyte concentrations) using CaCl₂ solution, indicating a higher Cu and Zn released when their total content was low. Generally, Cd, Cu, and Zn speciation was affected by both type of electrolytes and their concentrations, whereas Ni speciation stayed mostly stable and was almost unaffected by applied solutions. It can be suggested that beside competition with cations, chloro-complexation is important parameter in Cd release, while CuOH⁺, and to some extent ZnOH⁺ are important species affecting release of Cu and Zn. The distribution coefficient (K_d) values for each metals greatly varied with the types of electrolytes and electrolyte concentration. On the basis of average percentage of metal released under different electrolytes and concentrations the following sequences was found: Cd > Cu > Ni > Zn. The results are important in understanding the mobility of metals under different solutions and indicating that, Cd and Zn soils may pose a higher and lower mobility and ecological risk in contaminated calcareous soils, respectively.     

Biosorption of heavy metals by Saccharomyces cerevisiae

Abundant and common yeast biomass has been examined for its capacity to sequester heavy metals from dilute aqueous solutions. Live and non-living biomass of Saccharomyces cerevisiae differs in the uptake of uranium, zinc and copper at the optimum pH 4–5. Culture growth conditions can influence the biosorbent metal uptake capacity which normally was: living and non-living brewer's yeast: U > Zn > Cd > Cu; non-living baker's yeast: Zn > (Cd) > U > Cu; living baker's yeast: Zn > Cu (Cd) > U. Non-living brewer's yeast biomass accumulated 0.58 mmol U/g. The best biosorbent of zinc was non-living baker's yeast ( 0.56 mmol Zn/g). Dead cells of S. cerevisiae removed approximately 40% more uranium or zinc than the corresponding live cultures. Biosorption of uranium by S. cerevisiae was a rapid process reaching 60% of the final uptake value within the first 15 min of contact. Its deposition differing from that of other heavy metals more associated with the cell wall, uranium was deposited as fine-needle-like crystals both on the inside and outside of the S. cerevisiae cells.     

Metal-induced inhibition of anaerobic metabolism of volatile fatty acids and hydrogen

The effects of copper (Cu), chromium (Cr), cadmium (Cd), lead (Pb) and zinc (Zn) on the biotransformation of organic acids (acetate, propionate and butyrate) and H₂ were assessed in serum-bottle microcosms. Experiments were performed over a range of metal concentrations (20–200 mg/1) using biomass from an anaerobic bioreactor fed continuously with ethanol distillery waste as inoculum. In general, the added metals inhibited the biotransformation of organic acids with increasing metal concentration. However, the extent of inhibition varied for the different biotransformations and for the different metals tested. For example, the concentration of CuCl₂ effecting a 50% reduction in the rate constant for biotransformation of acetate, propionate and butyrate was 60, 75 and 30 mg/1, respectively. Cu and Cr (VI) were the most inhibitory metals in organic acid transformation, whereas Pb was the least toxic. The rate of biotransformation of acetate was reduced by half at Cu and Cr concentrations of 60 and 40 gm/1 respectively, whereas Cd, Pb, and Zn concentrations of 160 to 200 mg/l had little effect. The activities of hydrogenotrophic methanogens were much less affected by the same metals and metal concentrations.     

Properties of metallothionein induced by zinc, copper and cadmium in the frog, Xenopus laevis

1. Repeated injections of zinc (Zn) and copper (Cu) into the frog Xenopus laevis caused accumulations of the respective metals in the liver and kidney. 2. The accumulated metals in the liver supernatant fractions were present as Zn- and Cu-binding proteins of the same properties as that of metallothionein (MT) induced by cadmium (Cd) injections. 3. The affinity of Zn, Cu and Cd ions to the metal-binding protein was in the decreasing order of Cu, Cd and Zn. 4. The Xenopus MT induced by Cd was unstable and disrupted easily to give two peaks as if the MT consists of two isometallothioneins.     

重金属诱导拟南芥原生质体DNA 损伤的单细胞凝胶电泳检测

以拟南芥原生质体为实验体系, 研究不同浓度的3种重金属离子对拟南芥原生质体的毒性和DNA损伤的差异。结果表明, 用1-5 mmol.L-1的Zn2+、Cd2+ 和Cu2+分别处理的拟南芥原生质体, 2 小时内活力逐渐下降, 并表现出明显的浓度依赖性;与相同浓度的Cd2+ 和Cu2+ 相比, Zn2+对拟南芥原生质体活力的影响程度较小, 表现出较低的毒性。单细胞凝胶电泳检测发现,用0.1-0.8 mmol .L-1的Zn2+、Cd2+ 和Cu2+ 分别处理拟南芥原生质体30 分钟, 以OTM值表示的原生质体DNA损伤量随重金属离子浓度的增加而递增; 相同浓度(0.5 mmol.L-1)的3种重金属离子相比, Zn2+对原生质体的遗传毒性明显低于Cu2+ 和Cd2+。综合原生质体活力和DNA损伤的单细胞凝胶电泳检测结果, 发现Zn2+对拟南芥原生质体的遗传毒性较低, 而Cd2+ 和Cu2+的遗传毒性较高。本研究建立的拟南芥原生质体实验体系, 结合运用单细胞凝胶电泳技术, 能够快速、灵敏地检测重金属对植物细胞的遗传毒性。     

Biosorption of lead, cadmium, and zinc by Citrobacter strain MCM B-181: characterization studies

The biosorption process for removal of lead, cadmium, and zinc by Citrobacter strain MCM B-181, a laboratory isolate, was characterized. Effects of environmental factors and growth conditions on metal uptake capacity were studied. Pretreatment of biomass with chemical agents increased cadmium sorption efficiency; however, there was no significant enhancement in lead and zinc sorption capacity. Metal sorption by Citrobacter strain MCM B-181 was found to be influenced by the pH of the solution, initial metal concentration, biomass concentration, and type of growth medium. The metal sorption process was not affected by the age of the culture or change in temperature. Equilibrium metal sorption was found to fit the Langmuir adsorption model. Kinetic studies showed that metal uptake by Citrobacter strain MCM B-181 was a fast process, requiring <20 min to achieve >90% adsorption efficiency. The presence of cations reduced lead, zinc, and cadmium sorption to the extent of 11. 8%, 84.3%, and 33.4%, respectively. When biomass was exposed to multimetal solutions, metals were adsorbed in the order Co2+ < Ni2+ < Cd2+ < Cu2+ < Zn2+ < Pb2+. Among various anions tested, only phosphate and citrate were found to hamper metal sorption capacity of cells. Biosorbent beads prepared by immobilizing the Citrobacter biomass in polysulfone matrix exhibited high metal loading capacities. A new mathematical model used for batch kinetic studies was found to be highly useful in prediction of experimentally obtained metal concentration profiles as a function of time. Metal desorption studies indicated that Citrobacter beads could, in principle, be regenerated and reused in adsorption-desorption cycles. In an expanded scale trial, biosorbent beads were found to be useful in removal/recovery of metals such as lead from industrial wastewaters.     

A Biomonitor for Tracking Changes in the Availability of Lakewater Cadmium over Space and Time

Determining the exposure of organisms to contaminants is a key component of Ecological Risk Assessments (ERAs). Effective estimates of exposure consider not only the total concentrations of contaminants in an organism's surroundings but also the availability of the contaminants to organisms. Contaminant availability can be inferred from mechanistic models and verified by measurements of contaminant concentrations in organisms. We evaluated the widespread lake-dwelling insect Chaoborus as a potential biomonitor for use in exposure assessments for three metals: cadmium (Cd), copper (Cu), and zinc (Zn). We show that larvae of this midge maintain constant their concentrations of the essential metals Cu and Zn and thus cannot be used to monitor them. In contrast, larval Cd concentrations varied widely both among lakes and in a given lake over time. We were able to relate these variations in biomonitor Cd to changes in lakewater Cd and pH using the Free Ion Activity Model (FIAM). Our results suggest that Chaoborus larvae could be used as an effective tool for estimating the Cd exposure of organisms in lakes for the purposes of ERAs.     

Metabolomics and Trace Element Analysis of Camel Tear by GC-MS and ICP-MS

Acne vulgaris is a very common skin disorder affecting human beings. There is a paucity of report on the role of heavy metals—lead (Pb) and cadmium (Cd)—globally, and trace metals—zinc (Zn) and copper (Cd)—particularly in Nigeria in the development/severity of acne vulgaris. This study is aimed to determine the blood levels of some heavy metals—cadmium and lead—and trace metals—zinc and copper—in acne vulgaris sufferers in a Nigerian population. Venous blood samples were collected from a total number of 90 non-obese female subjects consisting of 30 mild, 30 moderate and 30 severe acne vulgaris sufferers for blood Cd, Pb, Cu and Zn determination. They were age-matched with 60 females without acne vulgaris who served as the control subjects. Acne sufferers had significantly higher blood Cd and Pb (P = 0.0143 and P = 0.0001 respectively) and non-significantly different blood levels of Cu and Zn (P = 0.910 and P = 0.2140 respectively) compared to controls. There were significant progressive increases in blood levels of Cd and Pb (P = 0.0330 and P = 0.0001 respectively) and non-significant differences in the mean blood level of Cu and Zn (P = 0.1821 and P = 0.2728 respectively) from mild to moderate and severe acne vulgaris sufferers. Increases in blood Cd and Pb may play critical roles in the pathogenesis/severity of acne vulgaris, while Cu and Zn seem to play less significant roles in the development of this disorder in this environment.     

Health risk assessment of heavy metals via dietary intake of wheat in Golestan Province,Iran

Concentration of five heavy metals including lead (Pb), cadmium (Cd), copper (Cu), iron (Fe), and zinc (Zn) in wheat collected from silages of Golestan Province, Iran, was determined using atomic absorption spectroscopy. Dry ashing method was applied for precise determination of the five heavy metal contents. The concentrations of heavy metals were recorded as the following: Pb (0.013–0.14), Cd (0.008–0.031) by graphite furnace method and Cu (0.48–6.2), Fe (58.50–406.9), and Zn (3.41–32.75) by flame method, all in mg.kg^?1. The mean concentration of all the aforementioned heavy metals was (0.057 ± 0.003), (0.016 ± 0.005), (2.7 ± 0.17), (111.2 ± 21), and (5.7 ± 0.22) mg.kg^?1, respectively. The level of heavy metals decreased in the order of Fe>Zn>Cu>Pb > Cd. Highest amount was related to Fe and the lowest amount to Cd. Concentrations of heavy metals in all the wheat samples were below the permissible limits set by the Food and Agriculture Organization/World Health Organization and Iranian National Standard Organization and did not pose any threat to the health of consumers.     

Influence of Ca/mg ratio on phytoextraction properties of Salix viminalis I. The effectiveness of Cd, Cu, Pb, and Zn bioaccumulation and plant growth

Phytoremediation and its efficiency--influenced by several factors-is prime concern in reduction of environment contamination with heavy metals. The aim of the study was to estimate in controlled conditions--in relation to the natural Ca/Mg ratio 4:1--the influence of different Ca/Mg ratios (1:1/4, 20:1, 1:10) on selected heavy metals (Cd, Cu, Pb, and Zn) accumulation efficiency shown by three morphological parts of Salix viminalis 'Cinamomea' (cane bark, shoots and roots). Accumulation of heavy metals in experimental conditions was significantly Ca/Mg ratio dependent, and occurred in the following order: 1:10 > 4:1 > 20:1 > 1:1/4. The highest accumulation under 0.5 mM solutions (as compared to 0.1 mM) was noted for copper and zinc, and the lowest for cadmium. Biometric parameters of Salix viminalis cuttings revealed the highest biomass productivity under 20:1 and 4:1 Ca/Mg ratios. In the case of shoot length increase, both metal concentration and kind of metal present in the solution were important. The results indicate that higher calcium ion concentration in solution (Ca/Mg 20:1) stimulates Salix viminalis growth by 3 fold when compared to other Ca/Mg ratio. It can be an important factor in remediation of the environment with this plant.     

Treatment of heavy metal-polluted wastewaters using the biofilms of a multistage rotating biological contactor

The ability of the biofilms of a three-stage rotating biological contactor (RBC) to treat wastewater contaminated with cadmium, copper and zinc was investigated. The system successfully removed the metals, in the order Cu > Zn > Cd with removal capacities of approximately 73, 42 and 33% respectively. Analysis of the contribution of each reactor indicated that metal removal was not uniform, with Reactor 1 showing a much higher removal capacity than Reactors 2 and 3. Energy dispersive X-ray spectroscopy (EDS) revealed the presence of all three metals on the surface of the biofilms in all three reactors. Closer inspection of the biofilms, in terms of biomass and biofilm thickness, revealed that the low metal removal in Reactors 2 and 3 was probably attributable to poor biofilm development in these two reactors compared to that in Reactor 1. The poor biofilm development was substantiated by low chemical oxygen demand (COD) removal in the latter two reactors.     

Trace metals and micronutrients in bone tissues of the red fox <Emphasis Type="Italic">Vulpes vulpes</Emphasis> (L., 1758)

In this study we determined the levels of trace elements (zinc, copper, lead, cadmium and mercury) in three layers of bones of the hip joint (cartilage, compact bone and spongy bone) of 30 red foxes (Vulpes vulpes) from north-western Poland. Concentrations of Cu, Zn, Pb and Cd were determined by atomic absorption spectrophotometry (ICP-AES) in inductively coupled argon plasma using a Perkin-Elmer Optima 2000 DV. Determination of Hg concentration was performed by atomic absorption spectroscopy. In cartilage, compact bone and spongy bone samples from the red fox, median concentrations of the metals studied could be arranged in the following descending series: Zn > Cu > Pb > Cd > Hg, the values ranging from 142 to 0.002 mg/kg dw. There was a significant difference in Cu concentrations, among all the materials analyzed, with much more Cu found in spongy bone than in compact bone. Significant differences were also noted in the case of Hg concentrations in cartilage with compact bone and the spongy bone, and between concentrations of this metal in compact bone and spongy bone. In males, the concentration of Hg in spongy bone was greater than in females. Younger foxes had a higher concentration of this metal in cartilage than adults. The strongest synergistic relationships were observed in spongy bone between the Zn and Cu, Zn and Cd, as well as between Cu and Cd. Statistically significant antagonistic relationships were detected between zinc and lead in compact bone. In addition to monitoring studies conducted on the abiotic environment, an urgent need exists for long-term monitoring of concentrations of heavy metals with long-term effects on living organisms. An important addition is provided by biomonitoring studies on domesticated and free-living mammals, including Canidae.     

Oxidative Stress Induced by Cadmium in the C6 Cell Line: Role of Copper and Zinc

In this report, we have investigated the role of copper (Cu) and zinc (Zn) in oxidative stress induced by cadmium (Cd) in C6 cells. Cells were exposed to 20 μM Cd, 500 μM Cu, and 450 μM Zn for 24 h. Then, toxic effects, cellular metals levels, oxidative stress parameters, cell death, as well as DNA damage were evaluated. Cd induced an increase in cellular Cd, Cu, and Zn levels. This results not only in the inhibition of GSH-Px, GRase, CAT, and SOD activities but also in ROS overproduction, oxidative damage, and apoptotic cell death not related to Cu and Zn mechanisms. The thiol groups and GSH levels decreased, whereas the lipid peroxidation and DNA damage increased. The toxicity of Zn results from the imbalance between the inhibition of antioxidant activities and the induction of MT synthesis. The increase in Cu and Zn levels could be explained by the disruption of specific transporter activities, Cd interference with signaling pathways, and metal displacement. Our results suggest that the alteration of Cu and Zn homeostasis is involved in the oxidative stress induced by Cd.     

Copper,Lead, Cadmium,and Zinc Sorption By Waterlogged and Air-Dry Soil

Competitive sorption of copper (Cu), lead (Pb), cadmium (Cd), and zinc (Zn) was studied in three soils of contrasting chemical and physical properties under air-dry and waterlogged conditions. Competitive sorption was determined using the standard batch technique using six solutions, each with Cu, Pb, Cd, and Zn concentrations of approximately 0, 2.5, 5, 10, 20, and 50?mg L^?1Waterlogged soils tended to sorb higher amounts of added Cu, Pb, Zn and Cd relative to soils in the air-dry condition; however, this increase in sorption was generally not statistically (p<0.05) significant. The magnitude of sorption under both waterlogged and air-dry conditions was affected by the type and amount of soil materials involved in metal sorption processes, and competition between other metals for the sorption sites. Metal sorption was closely correlated with soil properties such as cation exchange capacity, organic carbon, and Fe and Mn hydrous oxides. Exchangeable Al may have markedly reduced metal sorption due to its strong affinity for the sorption sites, while increases in exchangeable Mn may have enhanced Zn and Cd sorption. Heavy metal sorption was best described as a combination of both specific and nonspecific interactions. The extractability of Cu, Pb, Cd, and Zn under waterlogged and air-dry conditions was also studied. Three solutions containing these metals were mixed with each soil to achieve a final concentration of 0, 50, and 500?mg kg^?1. Each soil was extracted every 7 days using 1?M MgCl₂ (pH 7) to determine metal extractability. Metal extractability initially decreased then increased due to waterlogging. The increased extractability of added metals was closely related to increased solubility of Fe and Mn suggesting that dissolution of Fe and Mn, oxides under reducing conditions caused a release of previously sorbed Cu, Pb, Cd, and Zn.     

Effects of pretreatment with cadmium on the discriminative uptake of subsequent cadmium, copper or zinc by the liver

1. Effects of pretreatment with cadmium (Cd) on the uptake by the liver of subsequent Cd, copper (Cu) and zinc (Zn) were examined at two different time intervals to elucidate the biological discrimination mechanism among metals of similar chemical properties. 2. Pretreatment with 0.3 mg Cd/kg body wt 6 hr but not 24 hr before a subsequent dose of 0.8 mg metal/kg body wt enhanced the disappearance rate from plasma and accumulation rate in the liver of Cu (and Zn) but not of Cd. 3. Synthesis of metallothionein was induced with different time-courses depending on the time interval between the pretreatment and subsequent treatment, which coincided with the accumulation curves for Cu (and Zn) but not for Cd. 4. Although uptake of Cd was not enhanced by any pretreatment, metallothionein synthesis was enhanced depending on the timing of pretreatment.     

Nutrient partitioning and storage in arid-zone forests of the mangroves Rhizophora <Emphasis Type="Italic">stylosa</Emphasis> and <Emphasis Type="Italic">Avicennia</Emphasis><Emphasis Type="Italic">marina</Emphasis>

Mangrove partitioning and storage of macronutrients and trace metals were examined in different arid coastal settings of Western Australia. Total living biomass in three Rhizophora stylosa forests, which ranged from 233 to 289 t DW ha^-1, was significantly greater than biomass in three Avicennia marina forests (range: 79-155 t DW ha^-1). Although prop roots and stems were the largest single tree components for R. stylosa and A. marina, respectively, most nutrients were stored in leaves and living roots of both species. However, only a small fraction of the total nutrient pool was vested in tree biomass; the vast bulk was in soils. A large below-ground pool of dead fine roots was identified at all stands, equivalent to 36-88% DW of total living tree biomass. The amount of Ca, S, Cl, Na, Si, Fe, Mn, Zn, B, Mo and Cu vested in dead roots of both species was greater than in the total living tree biomass. The proportion of Fe and S vested in live and dead roots was exceptionally large, consistent with previous evidence of metal plaques on mangrove roots. Sulphur, iron and zinc in dead roots of both species constituted the bulk of these metals. R. stylosa trees preferentially accumulated more Mg, S, Cl, Na, Si, Fe, Mn, B and Mo than A. marina trees. Proportionally greater storage of P, N, Ca, K, Cu and Zn occurred in two of the three A. marina forests. Foliar concentrations of Mg, S, Mn, B and Mo in mangrove leaves were at the high end of the range reported for other tropical trees, but other elemental concentrations were at the low or mid-range. Nitrogen limitation in these forests is implied by a positive correlation between total tree N and net canopy production and by a lower percentage of ecosystem N in tree biomass as compared with other forests. Unlike terrestrial forests where a large proportion of nutrient capital is vested in floor litter, most elements in these mangrove forests are stored in dead roots. A large reservoir of dead roots below the forest floor may serve as a conservation mechanism, particularly in such arid oligotrophic environments.     

The effect of the trematode invasion and accumulation of heavy metals onto the pond snail (Mollusca: Gastropoda: Lymnaeidae)

The cumulating of heavy metals (Cu, Cd, Pb, Zn) by the pond snail Lymnaea stagnalis from river and pond populations in a norm and under the trematode infection was examined. The copper and cadmium were accumulated by all specimens, mainly in the mantle and leg, in less content--in the hepatopancreas, and in the least content--in the shell and haemolymph. The lead was accumulated most intensively by the river specimens in the shell and mantle, while in the pond specimens it was accumulated in the mantle and leg. The greatest content of zink was found in the mantle, leg, and hepatopancreas. According to the ratio of cumulation the heavy metals by the river and pond populations the following series of ions were obtained respectively: Pb > Zn > Cu > Cd and Zn > Pb > Cu > Cd. The difference between uninfected specimens and one infected with trematodes was recorded in the ratio of cumulated heavy metals, in the ratio of benthic biological accumulation, and also based on bending force between metals compared in pairs. An intensity of differences was directly proportional to the intensity of the trematode infection.