The Bhopal accident and methyl isocyanate toxicity.
The Bhopal accident, the world's worst industrial disaster, in which nearly 40 metric tons of methyl isocyanate (MIC) was released from the Union Carbide pesticide plant, occurred nearly 10 yr ago during the night of December 2 and 3, 1984. Over 3000 people residing in areas adjacent to the plant died of pulmonary edema within 3 d of the accident. Follow-up studies revealed pulmonary, ophthalmic, reproductive, immunologic, neurological, and hematologic toxicity among the survivors. Despite high reactivity, MIC can traverse cell membranes and reach distant organs, perhaps as a reversible conjugate with glutathione, which may explain some of the systemic effects of MIC. MIC can be degraded as a result of pyrolysis and interaction with water, but none of the breakdown products can duplicate the toxicity observed in Bhopal and in animal models. MIC may be the most toxic of all isocyanates because of its very high vapor pressure relative to other isocyanates and because of its ability to exert toxic effects on numerous organ systems.
Varma
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Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada.
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D000062:Accidents, Occupational; D000818:Animals; D002319:Cardiovascular System / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D004190:Disasters; D005123:Eye / Q000187:drug effects; D006168:Guinea Pigs; D006801:Humans; D007109:Immunity / Q000187:drug effects; D007194:India; D017953:Isocyanates / Q000737:chemistry / Q000506:poisoning* / Q000633:toxicity; D008168:Lung / Q000187:drug effects; D051379:Mice; D009420:Nervous System / Q000187:drug effects; D011817:Rabbits; D051381:Rats; D012098:Reproduction / Q000187:drug effects; D012140:Respiratory Tract Diseases / Q000139:chemically induced* / Q000401:mortality; D012867:Skin / Q000187:drug effects
D017953:Isocyanates; C008461:methyl isocyanate