SIX YEARS AGO, on December 3, 1984, a toxic gas leak at a Union Carbide pesticide plant in Bhopal, India, released methyl isocyanate (MIC) and its reaction products. The number of persons "exposed" and "injured" remains uncertain.1Official estimates from the Indian government place the dead at around 1800.2Others estimate mortality to have been between 2500 and 5000 and the number of injured to have been up to 200 000.3,4 Until the Bhopal incident, neither deaths nor cases of toxic effects from MIC exposure had been recorded inIndex Medicus.51 We have extensively surveyed the medical literature concerning effects of MIC exposure on the victims of the disaster and laboratory studies in animals. A great deal has been learned, but many questions still remain unanswered. THE BHOPAL PLANT In 1969, the Union Carbide Corporation built a formulation plant in Bhopal, India, to mix and

https://jamanetwork.com/journals/JAMA/articlepdf/384175/jama_264_21_037.pdf

Bhopal Tragedy's Health Effects: A Review of 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.

The Bhopal Accident and Methyl Isocyanate Toxicity

S. Sriramachari The multi-disciplinary study of histopathology and toxicology of Bhopal gas tragedy resolved se veral issues. First, the progression of severe pulmonary oedema to chronic fibrosis was confirmed experimentally, following a single exposure to MIC. Analysis of the residue in Tank 610 revealed over 21 chemicals. Apart from MIC and HCN, some of them were tracked down to the blood and viscera of dead and living ‘exposees’. The rationale of NaTS therapy was substantiated by elevated urinary NaSCN levels in Double Blind Clinical Trials as well as patients. Apart from cyanide, the ‘cherry red’ discolouration was also shown to result from binding of MIC to end -terminal valine residues of Hb, as shown by changes in 2 –3DPG levels and blood gas profiles. The finding of N carbamoylation of several other end-terminal amino acids of tissue proteins confirmed the distrib ution of MIC within the body, although the underlying mechanism is not yet fully understoo d. Possibly, the much faster S-carbamoylated compounds of the blood like glutathione and other sulphydrylcontaining enzymes like rhodanese could be responsible for re-circulation of MIC and protracted cyanide toxicity. It is hoped that eventually the enigma of the ‘Bio-chemical Lesion’ of MIC toxicity will be unraveled.

http://www.indiaenvironmentportal.org.in/files/The%20Bhopal%20gas%20tragedy.pdf

The Bhopal gas tragedy: An environmental disaster

Different approaches are necessary when community-based participatory research (CBPR) of environmental illness is initiated after an environmental disaster within a community. Often such events are viewed as golden scientific opportunities to do epidemiological studies. However, the authors believe that in such circumstances, community engagement and empowerment needs to be integrated into the public health service efforts in order for both those and any science to be successful, with special care being taken to address the immediate health needs of the community first, rather than the pressing needs to answer important scientific questions. The authors will demonstrate how they have simultaneously provided valuable public health service, embedded generalizable scientific knowledge, and built a successful foundation for supplemental CBPR through their on-going recovery work after the chlorine gas disaster in Graniteville, South Carolina.

GRACE: Public Health Recovery Methods Following an Environmental Disaster

Carbaryl, a methyl carbamate insecticide, is known for its wide application and low mammalian toxicity. The use of carbaryl in tropical agriculture is of recent origin and the degradation pattern of carbaryl in tropical environment is, thus very scantly. The present report therefore deals with the residues of 1-naphthol present in soil and water samples collected in and around Bhopal, India where carbaryl was commercially produced on large scale for more than a decade.

Residues of 1-naphthol in soil and water samples in and around Bhopal, India.

Effect of exposure to toxic gas on the population of Bhopal: Part III--Assessment of toxic manifestations in humans--haematological and biochemical studies.

Behari

Papers

Effect of exposure to toxic gas on the population of Bhopal: Part III--Assessment of toxic manifestations in humans--haematological and biochemical studies.