Toxic agents copper

There are several such toxic agents that cause considerable medical, public and political concern. Two examples are discussed here the heavy metal ions (e.g. lead, mercury, copper, cadmium) and the fluorophosphonates. Heavy metal ions readily form complexes with organic compounds which are lipid soluble so that they readily enter cells, where the ions bind to amino acid groups in the active site of enzymes. These two types of inhibitors are discussed in Boxes 3.5 and 3.6. There is also concern that some chemicals in the environment, (e.g. those found in industrial effluents, rubbish tips and agricultural sprays), although present at very low levels, can react with enhanced reactivity groups in enzymes. Consequently, only minute amounts concentrations are effective inhibitors and therefore can be toxic. It is suggested that they are responsible for some non-specific or even specific diseases (e.g. breast tumours). 

Many free-radical scavengers (including dithiols and dithiocarbamates) have potential therapeutic usefulness as radioprotective agents. Copper complexes are known to be scavenging agents for the superoxide radical, which is believed to play a role in the induction of radiation damage. The toxic effects of superoxide are believed to lie in its ability to reduce metal ions, for example Cu(II) to Cu(I),... 

In the early 1970s, Zitko et al. (1973) noted that HAs reduced the activity of the free Cu " ion, as measured by the copper ion-selective electrode, and that this effect was quite well correlated with the observed toxicity of Cu(II) to salmon. Soon thereafter, Pagenkopf et al. (1974) also reported on the effect of complexation on the toxicity of copper to fishes. Sunda and Guillard (1976) demonstrated that the activity of the free Cu " ion in synthetic growth media containing the metal complexing agent TRIS (2-amino-2-hydroxy-methyl-1,3-propanediol) was an excellent... 

Powell (1946) and Mason (1948) found that the 2 1 complex of 8-hydroxyquinoline with copper, oxine-copper, has a stronger fungicidal action than 8-hydroxyquinoline. Albert et al. (1953) attributed this to the fact that the organic part of the compound makes copper lipoid-soluble and thus accelerates its penetration into the cell. Inside the cell the 2 1 complex dissociates into a 1 1 complex and free 8-hydroxyquinoline. The active toxic agent is the ionised 1 1 complex of nonlipoid properties, which reacts with the enzymes in the fungus and blocks their function. This theory is also supported by the research work of McNew and Gershon (1969). 

A condition known as absinthism was observed in chronic consumers of the alcoholic beverage absinthe, which contains wormwood extract. The condition was described as a form of alcoholism that included delirium, hallucinations, tremors, and seizures (Lee and Balick 2005). While the compound thujone was once thought to be the primary cause of the psychotropic activity and toxicity of absinthe, recent analyses of absinthe indicate that the thujone content of historical and contemporary samples is insignificant and that other ingredients, such as the coloring agents copper sulfate or antimony chloride, may have been responsible for the adverse effects of absinthe (Blaschek et al. 2002 Lachenmeier et al. 2008). 

Classification Azobenzene Empirical C32H2oN4Na208S2 Properties Red powd. sol. (mg/ml) 1-10 mg water (20 C), < 1 mg in DMSO, 95% ethanol, acetone (20 C) m.w. 698.64 m.p. > 300 C Toxicology Mutagenic data TSCA listed Precaution Probably combustible incompat. with oxidizing and reducing agents copper dulls color iron makes it much duller Hazardous Decomp. Prods. Heated to decomp., emits toxic vapors of NOx and SOx Storage Store ambient temps. 

Precaution Incompat. with strong oxidizing agents, copper, copper alloys, aluminum insolubilized by chromic salts capable of creating dust explosion in powd. form Hazardous Decomp. Prods. CO, CO2, NOx, ammonia emits toxic fumes underfire conditions... 

The widespread use of many metals such as silver, cadmium, copper, mercury, nickel, lead, and zinc has resulted in their accumulation in the environment. Sediments are often the repositories of toxic metals (e.g.. Table 15-2). For example, copper is used as an anti-biofouling agent in marine paints and many harbor sediments contain markedly elevated levels of copper. 

Copper sulfate is used to control protozoan fish ectoparasites including Ichthyopthirius, Tri-chodina, and Costia. The effectiveness of the treatment diminishes with increasing total alkalinity and total hardness of the water (Straus and Tucker 1993). Copper compounds now used to control protozoan parasites of cultured red drum (Sciaenops ocellatus) include copper sulfate, copper sulfate plus citric acid, and chelated copper compounds (forms of copper bound by sequestering agents, such as ethanolamine) chelated copper compounds are considered less toxic to fish than copper sulfate and at least as effective in controlling parasites (Peppard etal. 1991). 

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