Chromium active carcinogen

Robison SH, Cantoni O, Costa M (1984) Analysis of metal-induced DNA lesions and DNA repair replication in mammalian cells. Mutat Res 131 173-181 Rodney PF, Robert JJ, Lay PA, Dixon NE, Raker RSU, Bonin AM (1989) Chromium (V)-induced cleavage of DNA are chromium (V) complexes the active carcinogens in chromium (Vl)-induced cancer Chem Res Toxicol 2 227-229... 

Under laboratory conditions, chromium is mutagenic, carcinogenic, and teratogenic to a wide variety of organisms, and Cr 6 has the greatest biological activity. However, information is lacking... 

Bacteria indigenous to Cr(VI)-polluted areas are Cr(VI) tolerant and/or resistant and have been considered as potential candidates for bioremediation of Cr(VI)-contaminated sites.16 However, the ability of bacteria to reduce Cr(VI) to the less-toxic Cr(III) compounds may produce reactive intermediates (such as Cr(V), Cr(IV), radicals), which are known to be active genotoxins and are likely to be carcinogenic.17 Therefore, the formation and lifetimes of Cr(V) intermediates, produced via bacterial reduction of Cr(VI), need to be evaluated carefully if microorganisms are to be employed as a means for remediation of chromium-polluted subsurface environments. Similarly, Cr(V) accumulation should first be monitored when considering plants and algae as biosorption materials for the bioremediation in the event of chromium pollution.18... 

There is now much interest in the biology of chromium,1086"1088 which has been suggested to be involved not only in the action of insulin, but also in the activation of certain enzymes, and, possibly, the stabilization of nucleic acids. Chromium is also known to be carcinogenic and mutagenic at high concentrations, particularly as chromate. Chromate is reduced in rat liver microsomes to Crm and Crv. Crv is labile and may well be the carcinogenic form.1089... 

A variety of industrial materials, including metallic compounds (both organic and inorganic), are produced by multiple anthropogenic activities. Because of the manner of use and disposal, these often reach the environment and cause a plethora of potential health hazards.4 Of the above symptoms, the risk for CNS disturbances in a child s development or in the human adult has gained importance. Information concerning different metals (e.g., arsenic, cadmium, chromium, lead, mercury, many other compounds) and their possible carcinogenicity has been documented as a national priority in the literature (Table 3-1).6-1011... 

Levy LS, Venitt S. 1975. Carcinogenic and mutagenic activity of chromium containing materials. Br J Cancer 32 254-255. 

Group 6B includes both chromium and molybdenum as essential trace elements. The oxidation state of Cr is of critical importance to its biological activity. The most common oxidation state is Cr3+ or Cr(III). Chromium(VI) is used in electroplating and in other industrial applications and is recognized as a carcinogen when inhaled. The essentiality of Cr was discovered when weaning rats were fed Cr-deficient diets,... 

Zhitkovich A, Quievryn G, Messer J, Motylevich Z. Reductive activation with cysteine represents a chromium(ni)-dependent pathway in the induction of genotoxicity by carcinogenic chromium(VI), Environ Health Perspect 2002 110 Suppl 5 729-31. 

The search is on for catalysts to replace those containing toxic heavy metals. The addition of hydrogen chloride to acetylene to form vinyl chloride is catalyzed by mercuric chloride. Rhodium (III) chloride on activated carbon works just as well and is much less toxic 97 It should be tried also in other addition reactions of acetylene as well as in trans-esteriflcation reactions of vinyl acetate. The reduction of 2 ethyl-2-hexenal to 2-ethylhexanol can be catalyzed by a mixture of copper, zinc, manganese, and aluminum oxides in 100% yield.98 This is said to be a replacement for carcinogenic copper chromite. In Reaction 4.15, the amount of toxic chromium(II) chloride has been reduced from stoichiometric to catalytic (9-15 mol% chromium(II) chloride) by the addition of manganese metal.99... 

The carcinogenicity of chromium(VI) compounds has been well-documented in epidemiological studies and animal tests Chromium(VI) compounds were mutagenic in bacterial and mammalian cell systems whereas chromium(III) compounds were not active mutagens in the same test systems In subcellular assay systems both chromium(III) and chromium(VI) decreased the fidelity off. Coli DNA polymerase The differences in activity of chromium(VI) compared to chromium(III) in cellular and subcellular systems have been explained in terms of the uptake-reduction model of chromate carcinogenicity ... 

Paradoxically, both apoptosis and the inhibition of apoptosis can be carcinogenic. Generalized apoptosis of a cell population may select for apoptosis-resistant cells. The inhibition of apoptosis may allow for the growth and replication of cells that contain substantial DNA damage, thus perpetuating potentially carcinogenic cell traits. Chromium (VI) appears to do both of these, as it initially activates and later inactivates p53. 

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