Metal ions toxic

Fig. 15-11 Effects of strong complexation on metal ion toxicity, (a) Increasing concentration of NTA, a strong multi-dentate complexing agent, decreases the toxicity of Cd to grass shrimp. All systems have equal concentrations of total Cd. (b) When the results are replotted showing survival as a function of Cd concentration, the data for all concentrations of NTA collapse to a single curve. (Reprinted with permission from W. G. Sunda et al. (1978). Effect of chemical speciation on toxicity of cadmium to grass shrimp, Palaemonetes pugio importance of free cadmium ions. Environ. Sci. Technol. 12,409-413, American Chemical Society.)...

Hammond, P. B. Foulkes, E. C. (1986). Metal ion toxicity in man and animals. In Metal Ions in Biological Systems, ed. H. Sigel, pp. 157-200. New York Marcel Dekker. 

As shown in Fig. 2, the Gd3+ ion enhances the relaxation rate of the protons of water molecules located at a distance r from the metal center in the first coordination sphere of the metal ion. The relaxivity is thus primarily affected by the hydration of the metal ion. Toxicity reasons however limit the maximum num-... 

Martin RB (1986) Bioinorganic chemistry of metal ion toxicity. In Sigel H (ed) Concepts on Metal Ion Toxicity (Metal Ions in Biological Systems), vol 20. Marcel Dekker, New York p21-65... 

Metal ion toxicity copper Local water quality... 

Extraction and manufacture of Zn, Pb, and Cu ores can give pollution of the environment with Cd derivatives. Cd is present also in industrial sludge and waste water. A source of Cd release is the burning of fossil fuels and the incineration of rubbish. Fertilizers can contain variable amount of Cd. Toxicological characteristics and environmental fate of Cd resemble those of Pb and Hg (see Metal Ion Toxicity). In aqueous environment Cd + shows a relative mobility it depends on pH, presence of organic molecules, and... 

Biomineralization Calcium-binding Proteins Metal Ion Toxicity Metal-mediated Protein Modification Metalloreg-ulation Nucleic Acid-Metal Ion Interactions Nutritional Aspects of Metals Trace Elements. 

Chromium Organometallic Chemistry Coordination Organometallic Chemistry Principles Magnetism of Transition Metal Ions Metal Ion Toxicity Nutritional Aspects of Metals Trace Elements Oxidation Catalysis by Transition Metal Complexes. 

Copper Hemocyanrn/Tyrosinase Models Copper Proteins with Dinuclear Active Sites Copper Proteins with Type 1 Sites Copper Proteins with Type 2 Sites Cytochrome Oxidase Electron Transfer Reactions Theory Long-range Electron Transfer in Biology Metal Ion Toxicity Metal-related Diseases of Genetic Origin Metallochaperones Metal Ion Homeostasis Nutritional Aspects of Metals Trace Elements. 

Biomineralization Iron Heme Proteins Dioxygen Transport Storage Iron Heme Proteins Electron Transport Iron Heme Proteins, Mono- Dioxygenases Iron Heme Proteins, Peroxidases, Catalases Catalase-peroxidases Iron Inorganic Coordination Chemistry Iron Proteins with Dinuclear Active Sites Iron Proteins with Mononuclear Active Sites Iron-Sulfur Proteins Iron Transport Siderophores Metal Ion Toxicity. 

Iron Inorganic Coordination Chemistry Iron Proteins for Storage Transport their Synthetic Analogs Iron-Sulfur Proteins Ligand Field Theory Spectra Metal Ion Toxicity Metalloregulation. 

Although mercury has been used medicinally, the element and its compounds are generally very toxic (see Metal Ion Toxicity). For reasons of economy, conservation, and public health, mercury use is gradually falling back to instances where no substitute can be found and recovery efforts are becoming more scrupulous. 

Alloys Anunonia N-donor Ligands Hard Soft Acids and Bases Mercury Qrganometallic Chemistry Metal Ion Toxicity S-donor Ligands Semiconductor Interfaces Superconductivity Water O-donor Ligands Zeolites. 

This chapter does not focus primarily on metal toxicity, although metals may be toxic and damage lung tissue, especially in particulate form and in industrial settings. For comprehensive coverage of this topic see Reference 1. This chapter deals with metal ion toxicity because it is via their ions that metals are presented as toxic substances to most of us. 

Metal ion toxicity does not relate to essentiality. Toxicity and essentiality do share, however, one feature frequent interdependencies among metal ions, between metal ions and nonmetals, and between both, and organic molecules such as vitamins. For example, excess Zn + may reduce absorption of essential Cu +, while a deficiency of Zn + worsens Cd + toxicity. Such antagonisms and mutual dependencies produce variable toxicities for like concentrations of an element. 

Zinc efflux is mediated by a zinc exporter known as ZntA (Zn + transport or tolerance), a membrane protein which was identified through studies of bacterial strains that were hypersensitive to zinc and cadmium. Sequence inspection revealed that ZntA was a member of the family of cation transport P-type ATPases, a major family of ion-translocating membrane proteins in which ATPase activity in one portion of the protein is used to phophorylate an aspartate within a highly conserved amino acid sequence, DKTG, in another portion of the protein. The cysteine rich N-terminus of these soft metal transport proteins contains several metal-binding sites. How the chemical energy released by ATP hydrolysis results in metal ion transport is not yet known, in part because there is only partial information about the structures of these proteins. The bacterial zinc exporter also pumps cadmium and lead and is therefore also involved in protection from heavy metal toxicity (see Metal Ion Toxicity). 

Metal Ion Toxicity Metal-related Diseases of Genetic Origin. 

Coordination OrganometalUc Chemistry Principles Electron Transfer Reactions Theory Macrocyclic Ligands Metal Ion Toxicity Oxides Solid-state Chemistry Polynuclear Organometallic Cluster Complexes Sulfur Organic Polysulfanes Thallium Organometallic Chemistry. 

Elemental thallium and its compounds are extremely toxic and must be handled with care (see Metal Ion Toxicity). The lethal dose is considered to be 10-12mg kg body... 

Iron Transport Siderophores Metal Ion Toxicity Metal-related Diseases of Genetic Origin Metallochaperones Metal Ion Homeostasis MetaUoregulation Metallothioneins ... 

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