Chromate, poisoning

Kerr, L.A. and W.C. Edwards. 1981. Chromate poisoning in livestock from oil field wastes. Veterin. Human Toxicol. 23 401-402. 

Reagor, J.C. and D. McDonald. 1980. Chromate poisoning in cattle — a case report. Southwest. Veterin. 33 10-11. 

Borate and chromate poisoning cause oliguria which is treated with supplementation of N-acetylcysteine (Banner et al. 1986). N-Acetylcysteine also reduces paracetamol (acetaminophen) toxicity (Flanagan and Meredith 1991), by diminishing the analgesic effect (Levy 1986). 

Evidence that ascorbic acid might be part of the body s natural defences against chromate poisoning was provided by Simavoryan who showed in 1971, that potassium dichromate given to rats, either orally or via subcutaneous injection, led to a decrease in the ascorbic acid levels in the kidney. Samitz et al. investigated the in vitro reaction of chromate and ascorbic acid and showed spectrophotometrically that ascorbate reduced Cr(VI) to Cr(III) with accompanying complex formation. Since they did not mention the presence of a buffer in their reaction mixtures ( hexavalent Cr and 10% ascorbic acid ) the reactions were probably carried out at acid pH. 

Penicillamine (PSH), the dimethyl derivative of cysteine (structure given in Fig. 4), is not a natural metabolite but its reaction with chromate at pH 7 has been investigated because of its possible role as a detoxifying agent in chromate poisoning. In 1970 Sugiura, Hojo... 

All cases of accidental chromate poisoning in cattle have resulted from the exposure of animals to chromate compounds associated with oil-field activities. Chromates are used as a corrosion inhibitor between the pipe and casing and are often added to drilling fluids (in the form of chromeUgnosulfQnate) to improve thermal stability. One recorded case involved 20 mature cows and their 8-month-old calves. 

Chromates and dichromates are used in industry as oxidising agents, for example in the coal tar industry, in the leather industry (chrome taiming), and in the dye industry as mordants. Some chromates are used as pigments, for example those of zinc and lead. Chromates and dichromates are poisonous. 

Particulate Matter Other Phan Systemic Poisons. SUica and asbestos dust produce fibrosis. SUicon carbide, carbon (other than exhaust emissions), and emery are iuert dusts. Many organic dusts, eg, poUen, wood, and resius, cause aUergic reactions. Acids, alkaUes, fluorides, and chromates are irritants. 

Some compounds, such as strontium chromate and strontium fluoride, are carcinogens and toxic if ingested. Strontium-90 is particularly dangerous because it is a radioactive bone-seeker that replaces the calcium in bone tissue. Radiation poisoning and death may occur in people exposed to excessive doses of Sr-90. Strontium-90, as well as some other radioisotopes that are produced by explosions of nuclear weapons and then transported atmospherically, may be inhaled by plants and animals many miles from the source of the detonation. This and other factors led to the ban on atmospheric testing of nuclear and thermonuclear weapons. 

Toxicology. Lead chromate is a suspected human lung carcinogen and can cause chronic lead poisoning. 

Davies JM Long term mortality study of chromate pigment workers who suffered lead poisoning. Br jf Ind Med 41(2) 170-178, 1984... 

Barium Chromate (Lemon Chrome or Baryta Yellow), BaCr04, mw 253.37 heavy yel, rhombic crysts very poisonous mp - may be heated to 1000° without melting or decompg... 

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