PREVIEW OF EVENTS

The man made, Bhopal gas disaster occurred on 2/3rd December night of 1984. It was a cold winter night for the Bhopalites. The timing of the gas leak coincided with near midnight when most of the people were in deep somber. The event led to heavy mortality and morbidity, the worst tragedy recorded so far in the history of chemical industry. Right from the beginning after the disaster the medical community attending the gas affected, faced confusion in the interpretation of the observed toxicology of inhalation deaths. Further the problem was compounded by the Union Carbide Corporation timing their statements (UCC press conference, 14th December 1984). That when methyl isocyanate comes in contact with moisture, it turns into harmless compounds. it does not cross the lung barrier.

The major key reason for the differences in the interpretation of toxicology was due to lack of knowledge about the exact chemical composition of stored material and later of poison clouds that descended on the residents of Bhopal (Bucher, 1987). No clear cut treatment and management was available or postulated by Union Carbide Corporation. But a telex message (11th December 1984) from Disease Control Center at Atlanta, informed that :

a. No antidote known to methyl isocyanate exposure.

b. Give Cortisone and oxygen.

c. If cyanide poisoning suspected, it should be treated suitably.

Environmental Health Perspectives, Vol. 72 of 1987 edited by Bucher concludes that one could not know what were the composition of the contents of the tank, but for MIC HCN, what other things came out of the tank, what people inhaled ? It is because of the lack of this knowledge that the experiments can not be simulated on the animals. It is still a mystery that what reformulation and reconjugation of chemicals exposed to unknown pressure and temperature in a closed tank took place.

In addition to that very little information was available in the then scientific literature on the chemical and biological interactions of the initial reactant, methyl isocyanate. Few argued that it was only methyl isocyanate that spurted in 2-3 hours leak through safety valve from the Union Carbide India Limited (UCIL) tank E-610.

With many years experience in the investigative and reconstructive forensic medicine, on of us Professor Heeresh Chandra questioned himself the points which automatically arise in the scientific mind as follows :

1. Why so many people died with a material commercially manufactured and stored against all norms and never it was indicated, that it could be so dangerous to the humanity ?

2. What was the composition of the contents, i.e. reaction products in the gaseous or vapor form and particulate matter that were emitted from the tank ?

3. Naturally the question arises as to what and how much people inhaled at rest and during exodus ?

4. What were the reactions, that took place, one after the other in the tank ?

5. What was the role of temperature and pressure during the process of reaction and the escape of the contents ?

6. Since when the cooking of the event was going on in the tank - filled against all norms and kept over eight weeks, at the ambient temperature.

7. Why was the refrigeration unit removed six months prior to the event ?

8. Why were the hydrants not effectively functional ?

9. Why the scrubber was out of action and had insufficient capacity much below the proportionate capacity of neutralisation of methyl isocyanate ?

Looking to these aspect of the event, associated with deliberate neglect of norms, one has to consider the event from many angles with such mortality and morbidity - no clear-cut identity of poisoning was possible. Therefore, the source, i.e., the spot and the remains has to be looked into minutely in all possible details.

There is no irrespirable gas known so far, which could in the open space kill so many people and make many more morbid.

With conditions enumerated above, we decided upon to trace the events from the resultants, that is the viscera from the dead bodies and analysis of tank residue. We made Herculean efforts and exhibited our foresight admitting ab-initio that this is an unknown field and preserved the tissues at minus 700 C to analyse them later when the knowledge acquired and wisdom dawns on us. The present report is the result of such an exercise which has paid dividends. The analysis indicated that viscera contained in addition to reacted metabolites of methyl isocyanate numerous unidentified organic chemicals and some of them expectedly are the constituents of the tank residue as well.

Studies were carried out on the preserved autopsy samples collected periodically since 3rd December 1984. As a part project, work has also been carried out on MIC trimmer (1,3,5-trimethyl-perhydro-1,3,5-triazine-2,4,6-trione), DMI (1,2-dimethyl - perhydro-1,3,5-dione), etc that was reported (UCC, 1985; Varadarajan, 1985) as the major product (about 50%) in the 12.5 tons tank residue and other related chemical entities.

Tremendous amount of activity was generated in the scientific world in the study of Methyl Isocyanate toxicology (Varma DR, 1987; Bucher JR 1987; DRDE, 1987) after the Bhopal gas disaster event that occurred in the night of 2/3December 1984. Everyone in the world believed that the Union Carbide killer tank E-610 contained nothing but MIC, that was supposed to be stored by UCIL for more than six weeks (Varadarajan et al., 1985) at ambient temperature against all norms so prescribed by the manufacturer themselves. Yet another dimension was added with a question mark that MIC alone can not produce such a mortality and morbidity (UCC Bulletin - 86 persons exposed). The autopsy findings are against it and a satisfactory answer is lacking even on the mechanism of toxicity of MIC which underwent high reformulation and reconjugation under tremendous pressure and temperature generated.

"Before one can directly apply these results to exposed population in Bhopal, it should be kept in mind that while MIC was probably the primary chemical released during the accident, an as yet undetermined amount of reaction products was also released, perhaps including hydrogen cyanide. No attempt has been made to recreate the accident experimentally to examine defects in animals. The technical difficulties involved and lack of knowledge concerning the composition of the released materials preclude such an approach."