Heavy metal resistant ciliate, Euplotes mutabilis, isolated from industrial effluents can decontaminate wastewater of heavy metals.
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Animals↗
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Results for “Metals, Heavy”
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The mediation of mutagenicity and clastogenicity of heavy metals by physicochemical factors.
Heavy metals are an important class of environmental hazards, and as the use of heavy metals metals in industry continues to increase, larger segments of the biota, including human beings, will be exposed to increasing levels of these toxicants. As many heavy metals are mutagenic and clastogenic, they cause teratogenic and/or carcinogenic effects. Studies with microbes and representatives of the aquatic biota have shown that the toxicity of heavy metals is mediated by the physicochemical characteristics of natural environments. A few studies have also indicated that such abiotic factors (e.g. pH, chelating agents, inorganic anionic and cationic composition) mediate the mutagenicity and clastogenicity of heavy metals. These studies indicate that the physicochemical characteristics of natural environments may also potentiate or attenuate the mutagenicity and clastogenicity of heavy metals to the indigenous biota. Furthermore, studies with laboratory animals have shown that the acute and chronic toxicity, including the teratogenicity and carcinogenicity, of heavy metals is mediated by physicochemical factors. A similar dependence of the mutagenicity and clastogenicity of heavy metals by the physicochemical characteristics unique to specific body fluids and tissues may explain the association of specific heavy metal-induced tumors with specific tissues. There is an apparent need to develop genotoxicity tests that incorporate into their procedures the mediating influence of physicochemical factors (pH, for example), as the use of only standardized procedures may hinder the detection of heavy metal, as well as of organic, genotoxins whose mutagenicity or clastogenicity is altered by conditions other than those used in the standardized assay, thereby producing false negative results.
Animals↗
Heavy metals in normal Japanese tissues. Amounts of 15 heavy metals in 30 subjects.
To obtain the usual values of arsenic, beryllium, bismuth, cadmium, chromium, cobalt, copper, mercury, methyl mercury, manganese, molybdenum, nickel, lead, antimony, vanadium, and zinc in the normal human body, the amounts of 15 metals were determined in 15 male and 15 female Japanese cadavers (average weight, 55 kg [121 lb]). The content of metals found ranged as follows: Zn, 1,800 mg; Cu, 65 mg; Cd, 35 mg; Pb, 25 mg; Mn, 8 mg; Ni, 6 mg; Cr, 4 mg; Hg, 3 mg; Sb, 0.7 mg; MeHg, 0.4 mg. Cadmium and mercury were higher in Japanese blood than in blood of other people. Cadmium and mercury were absorbed by the metabolic tissues; Cr, Ni, and Pb showed higher concentration in tissue exposed to the environment. Concentrations of Cd, Pb, and Hg tended to be higher in females, and Cr Cu, MeHg, and Mn concentrations tended to be higher in males.
Adolescent↗
[Progress on monoclonal antibody directed toward metal-chelate complexes and immunoassays to assess heavy metal contamination].
Heavy metals increase pollution on the environment. Recently, immunoassays was developed in convenience to practicability. The ELISAs and fluorescence polarization immunoassay (FPIA) based on preparation of monoclonal antibody (McAb) directed toward various heavy metal-chelate complexes may have great potential for application. Progress on McAb selective recognition metal-chelate complexes and immunoassays to assess heavy metal contaminations was reviewed in this paper.
Animals↗
Ion exchange extraction of heavy metals from wastewater sludges.
Heavy metals are common contaminants of some industrial wastewater. They find their way to municipal wastewaters due to industrial discharges into the sewerage system or through household chemicals. The most common heavy metals found in wastewaters are lead, copper, nickel, cadmium, zinc, mercury, arsenic, and chromium. Such metals are toxic and pose serious threats to the environment and public health. In recent years, the ion exchange process has been increasingly used for the removal of heavy metals or the recovery of precious metals. It is a versatile separation process with the potential for broad applications in the water and wastewater treatment field. This article summarizes the results obtained from a laboratory study on the removal of heavy metals from municipal wastewater sludges obtained from Ardhiya plant in Kuwait. Data on heavy metal content of the wastewater and sludge samples collected from the plant are presented. The results obtained from laboratory experiments using a commercially available ion exchange resin to remove heavy metals from sludge were discussed. A technique was developed to solubilize such heavy metals from the sludge for subsequent treatment by the ion exchange process. The results showed high efficiency of extraction, almost 99.9%, of heavy metals in the concentration range bound in wastewater effluents and sludges. Selective removal of heavy metals from a contaminated wastewater/sludge combines the benefits of being economically prudent and providing the possibility of reuse/recycle of the treated wastewater effluents and sludges.
Industrial Waste↗
Identification of lead-regulated genes by suppression subtractive hybridization in the heavy metal accumulator Sesbania drummondii.
Heavy metal contamination of soils is of widespread occurrence as a result of human, agricultural and industrial activities. Among heavy metals, lead is a potential pollutant that readily accumulates in soils and sediments. Although lead is not an essential element for plants, it gets easily absorbed and accumulated in Sesbania drummondii, which exhibits a significant level of tolerance to lead. The response of a metal tolerant plant to heavy metal stress involves a number of biochemical and physiological pathways. To investigate the overall molecular response of a metal-tolerant plant to lead exposure, suppression subtractive hybridization (SSH) was used to construct a cDNA library enriched in lead induced mRNA transcripts from lead-tolerant Sesbania. Screening the library by reverse Northern analysis revealed that between 20 and 25% of clones selected from the library were differentially regulated in lead treated plants. After differential screening, we isolated several differentially expressed cDNA clones, including a type 2 metallothionein (MT) gene which is involved in detoxification and homeostasis and shown to be differentially regulated in lead treated plants. The data from the reverse Northern analysis was further confirmed with conventional Northern analysis of a select group of genes including MT, ACC synthase/oxidase, cold-, water stress-, and other abiotic stress-induced genes, which are up-regulated rapidly in response to lead treatment. The mRNA levels of MT increased substantially after lead treatment indicating a potential role for it under lead stress in Sesbania. The present results show that SSH can serve as an effective tool for isolating genes induced in response to lead heavy metal tolerance in Sesbania. A better understanding of lead induced gene expression in Sesbania should help select candidates associated with remediation of heavy metal toxicity. The possible link between this result and the heavy-metal response of plants is discussed.
Amino Acid Sequence↗
Factors involved in heavy metal poisoning.
The heavy metals include at least 40 elements but cadmium, lead, and mercury have been most extensively studied. The biological properties of heavy metals are discussed in terms of three important characteristics: the ability to form, irreversibly, complexes and chelates with organic ligands; the properties to form organic-metallic bonds; and the potential to undergo oxidation-reduction reactions. The formation of complexes and chelates within the body is shown to influence greatly the dynamics of transport, distribution, and excretion of several important metal cations. The excretion of uranium is influenced by acid-base balance in the body because uranium forms complexes with bicarbonate anions that are filtered by the kidneys. The biliary excretion of methylmercury depends on the formation of small molecular weight complexes with sulfur-containing amiono acids and the peptides in the liver. The degree of enterohepatic recirculation of a variety of heavy metals appears to depend on the chemical nature of the bilary complexes. The oxidation of elemental to divalent ionic mercury is the crurial step in the retention and tissue deposition of inhaled mercury vapor. That the oxidation process is, at least in part, catalyzed by the enzyme, catalase, explains the effects of ethanol, aminotriazole and the state of acatalasemia on the metabolism of inhaled vapor in man and animals. The formation of covalent bonds between metal cations and the carbon atom usually greatly modifies the biological properties of the metal. Methylarsenic and methylmercury compounds both differ from the inorganic forms in accumulation in animals.
Animals↗
The importance of vitamins in relation to the presence of heavy metals in food.
Heavy metals are among the most widespread potential chemical contaminants in the environment and may be transferred to man through diet. Cadmium, mercury and lead are those which are most dangerous to human health. The nutritional status of exposed subjects is of particular interest in the study of the biochemical and morphological changes linked to heavy metal intoxication. Some vitamins play an efficacious protective role through direct or indirect mechanisms which interfere with the intestinal absorption of heavy metals by increasing urinary excretion or creating a synergic effect on the chelating element. It is important to underline the importance of an adequate vitamin intake in the prevention and treatment of cadmium, mercury and lead intoxications.
Adult↗
Phospholipid Fatty Acid Composition and Heavy Metal Tolerance of Soil Microbial Communities along Two Heavy Metal-Polluted Gradients in Coniferous Forests.
The effects of long-term heavy metal deposition on microbial community structure and the level of bacterial community tolerance were studied along two different gradients in Scandinavian coniferous forest soils. One was near the Harjavalta smelter in Finland, and one was at Ronnskar in Sweden. Phospholipid fatty acid (PLFA) analysis revealed a gradual change in soil microbial communities along both pollution gradients, and most of the individual PLFAs changed similarly to metal pollution at both sites. The relative quantities of the PLFAs br18:0, br17:0, i16:0, and i16:1 increased with increasing heavy metal concentration, while those of 20:4 and 18:2(omega)6, which is a predominant PLFA in many fungi, decreased. The fungal part of the microbial biomass was found to be more sensitive to heavy metals. This resulted in a decreased fungal/bacterial biomass ratio along the pollution gradient towards the smelters. The thymidine incorporation technique was used to study the heavy metal tolerance of the bacteria. The bacterial community at the Harjavalta smelter, exposed mainly to Cu deposition, exhibited an increased tolerance to Cu but not to Cd, Ni, and Zn. At the Ronnskar smelter the deposition consisting of a mixture of metals increased the bacterial community tolerance to all tested metals. Both the PLFA pattern and the bacterial community tolerance were affected at lower soil metal concentrations than were bacterial counts and bacterial activities. At Harjavalta the increased Cu tolerance of the bacteria and the change in the PLFA pattern of the microbial community were found at the same soil Cu concentrations. This indicated that the altered PLFA pattern was at least partly due to an altered, more metal-tolerant bacterial community. At Ronnskar, where the PLFA data varied more, a correlation between bacterial community tolerance and an altered PLFA pattern was found up to 10 to 15 km from the smelter. Farther away changes in the PLFA pattern could not be explained by an increased community tolerance to metals.
Journal Article↗
[Heavy metal ions and micro-organisms: microbial resistance to heavy metal ions].
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Cadmium↗
[Transmembrane potential and ATP-ase activity of the plasma membrane of bacteria exposed to heavy metals].
Effect of heavy metals (gold, zinc and cadmium) on the ATPase activity and transmembrane potential (delta psi) as integral index of bacterial cells membrane processes intensity has been studied. It was shown that studied membrane systems of bacteria are very sensitive to the action of heavy metals and they can serve as indicators of resistance of bacterial cultures.
Adenosine Triphosphatases↗
[The heavy metal problem in food products and the approaches to using raw foodstuffs with a high content of heavy metals (a review)].
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Animals↗
Accumulation of heavy metals in freshwater molluscs.
Heavy metals in the aquatic environment have to date come mainly from naturally occurring geochemical materials. However, this has been enhanced by human activity such as gold mining in the case of heavy metal pollution in Sg Sarawak Kanan. The high suspended solid loads in the river have quite efficiently removed most soluble metals from the water and trapped them in the bottom sediment. Three freshwater mollusc species were collected at the point source of the heavy metal pollutants and analysed for the heavy metal contents in their tissues and shells. Two of the mollusc species (Brotia costula and Melanoides tuberculata) are purely freshwater species while the Clithon sp. nr retropictus is able to survive in fresh and brackish water environments. The Brotia costula and the Clithon sp. are the edible species which are sold in the market. Accumulation of As, Cu, Fe, Se and Zn in all the three mollusc species were determined and the level of As in the tissues of Brotia costula and the Clithon sp. was much higher than the permissible level for human consumption. The mollusc species also demonstrated different preferences for the uptake of different metals. Variations in the heavy metal contents in the shell and tissues of the same species were also observed.
Animals↗
Concentrations of heavy metals in maternal and umbilical cord blood.
Concentrations of lead, cadmium, methylmercury and total mercury were measured in maternal and umbilical cord blood using graphite atomic absorption spectrometry. Two essential metals, copper and zinc, were also determined using ion chromatography. Lead, copper and zinc were found to be lower in the cord blood whereas methylmercury and total mercury were higher in cord blood than in maternal blood. Little differences were noted for cadmium in maternal and cord blood. Significant positive correlations were observed between the concentrations in maternal and cord blood with regard to lead (correlation coefficient, r = 0.44), copper (r = 0.34), zinc (r = 0.29), methylmercury (r = 0.44) and total mercury (r = 0.58). These results suggest that, like essential metals, most heavy metals can move rather freely across the human placenta. The potential health effects of heavy metal transfer from mothers to young infants cannot be discounted.
Analysis of Variance↗
Application of covalent affinity chromatography with thiol-disulphide interchange for determination of environmental exposition to heavy metals based on the quantitative determination of Zn-thionein from physiological human fluids by indirect method based on analysis of metal contents.
Intoxication with heavy metals results in numerous poisonings and diseases. They disturb metabolism of the system, are the source of cancer, degeneration changes and others. As a result of kidney damage the urine of people exposed to heavy metals contains different low molecular weight proteins, oligopeptides and amino acids, indicating pathological changes. One of the proteins is a very specific metallopolythiopolypeptide--metallothionein (MT). Based on earlier investigations, a very good correlations has been found between the contents of metallothionein in urine and plasma and the concentration of heavy metals in the blood, urine, kidneys, liver and brain and general in level of exposition to heavy metals. The aim of our investigations was to carry out quantitative isolation of Zn-thionein (Zn-Th), in order to determine the level of exposition to heavy metals. For Zn-Th protein isolation by covalent affinity chromatography with thiol-disulphide interchange (CAC-TDI) was applied, which is a modern technique of separation of a high affinity, good repeatability and reproducibility, allowing specific isolation of the thiol-proteins CAC-TDI gel was used as a solid-phase extraction (SPE) support for preconcentration of Zn-Th protein and Zn bonded with Zn-Th from water, rine, plasma and breast milk samples. The investigations showed unfavourable effect of the support on separation of thiol proteins and good correlation between the concentration of MTs protein added to water, plasma and urine and the concentration of protein indirectly determined via atomic absorption spectrometric (AAS) method, by preconcentration on SPE support metals formerly bound with MT protein and absorbed on CAC-TDI gel and calculated from metals concentration. The present paper is a continuation of earlier experiments on quantitation of Hg-thionein and Cd-thionein in physiological fluids and homogenates.
Chromatography, Affinity↗
Industrial age anthropogenic inputs of heavy metals into the pedosphere.
Heavy metals have been increasingly released into our environment. We present here, for the first time, the global industrial age production of Cd, Cu, Cr, Hg, Ni, Pb, and Zn, and their potential accumulation and environmental effects in the pedosphere. World soils have been seriously polluted by Pb and Cd and slightly by Zn. The potential industrial age anthropogenic Pb, Hg, and Cd inputs in the pedosphere are 9.6, 6.1, and 5.2 times those in the lithosphere, respectively. The potential anthropogenic heavy metal inputs in the pedosphere increased tremendously after the 1950s, especially for Cr and Ni. In 2000, the cumulative industrial age anthropogenic global production of Cd, Cr, Cu, Hg, Ni, Pb, and Zn was 1.1, 105, 451, 0.64, 36, 235, and 354 million tonnes, respectively. The global industrial age metal burdens per capita (in 2000) were 0.18, 17.3, 74.2, 0.10, 5.9, 38.6, and 58.2 kg for Cd, Cr, Cu, Hg, Ni, Pb, and Zn, respectively. Acidification may increase the bioavailability and toxicity of heavy metals in the pedosphere. The improvement of industrial processing technology reducing the metal dispersion rate, the recycling of metal-containing outdated products, by-products and wastes, and the development of new substitute materials for heavy metals are possible strategies to minimize the effects of heavy metals on our environment.
Biological Availability↗
Heavy metal modulation of lymphocyte activities. 1. In vitro effects of heavy metals on primary humoral immune responses.
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Animals↗
[Exposure to metals, metalloids and their compounds in heavy metals refining].
BACKGROUND: In the process of heavy metals refining, workers are first of all exposed to metals, metalloids (As, Se) and their compounds. Moreover, they are exposed to sulphuric acid and dusts (about 2% SiO2). MATERIALS AND METHODS: Several dozen workers in two Polish plants were studied (Cu, Pb, Cd, Zn, and Ag refining processes, production of Ni sulphate and production of Se). Cd, Ni, Se, Cu, Pb, As and Ag were determined by atomic absorption spectrometry (AAS) with graphite tube, whereas ZnO (as Zn) by AAS with air-acetylene flame. Sulphuric acid was determined by the method given in PN-91/Z-04056/02, and dust (total and respirable fraction) by gravimetric methods. RESULTS: High concentrations of lead were found in the workplace air in both plants. Occupational exposure indicators for lead were much higher than the Polish MAC value. Exposure to arsenic and its compounds was a serious problem in one of the plants. Concentrations of the other chemical agents were generally below the Polish MAC values. CONCLUSIONS: Even though in many cases no risk is posed by individual metals and metalloids, total exposure is another matter. The total exposure indicator for present metals and metalloids at most workstations in both plants was higher than 1. In general, risk posed by metals and metalloids is high or even very high in the heavy metal refining industry.
Air Pollutants, Occupational↗