The Bhopal Gas Leak

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THE BHOPAL GAS LEAK:

ANALYSIS OF CAUSES AND CONSEQUENCES

Author

Ingrid Eckerman, MD, MPH. Member of the International Medical Commission on Bhopal, 1994. Medical advisor at Sambhavna Clinic, Bhopal.

Address: Statsradsvagen 11, SE 128 38 Skarpnack, Stockholm, Sweden.

E-mail: .

Abstract

The Bhopal Gas Leak, India 1984 is the largest chemical industrial accident ever. Haddon´s and Berger´s models for injury analysis have been tested, together with the project planning tool Logical Framework Approach (LFA).

The three models provide the same main message: That irrespectively of the direct cause to the leakage, it is only two parties that are responsible for the magnitude of the disaster: Union Carbide Corporation and the Governments of India and Madhya Pradesh. However, the models give somewhat different images of the process of the accident.

Keywords

Bhopal, gas leak, injury analysis, methyl-isocyanate, MIC.

Background

The Bhopal Gas Leak, India 1984 is the largest chemical industrial accident ever. 520,000 persons were exposed to the gases, and more than 2,000 died during the first weeks. 100,000 persons or more have got permanent injuries. The catastrophe has become the symbol of negligence to human beings from transnational corporations. It has thus served as an alarm clock. All the same, industrial disasters still happen, in India as well as in the industrialised part of the world. Although they are far from the size of Bhopal, they are so numerous so that chemical hazards could well be considered as a public health problem. The companies usually dispute their own roll to the accidents, and deny the health effects of the accidents. The companies have also been reluctant to compensate the victims economically.

There are still different opinions on the cause to the Bhopal disaster and who was responsible. According to Union Carbide, it was sabotage by a disgruntled worker.

In injury analysis, the conception “the process of the accident”, including pre-event, event and post event phases, is used. Many models for analysing the extent of injuries have been developed (Berger & Mohan, 1996). Usually they are used for events like traffic accidents and children’s burns. Two models for injury analysis was tested against a complex mega-accident. They were compared with the Logical Framework Approach (Logical Framework Approach, 1996), which is a tool for project planning and management.

In these analyses, it is considered proved that the reason that water entered tank 610 was the washing of pipelines.

The Haddon Model

The Haddon model has three components: the causal chain of events, the Haddon matrix, the Ten technological strategies and the Four E’s (Berger & Mohan, 1996).

To find which factors to include in the Haddon matrix, it is recommended that one should think of “a causal chain of events” leading to injuries. Yet the reasons for this accident are much more complicated. A number of chains could be drawn. I therefore suggest that the phrase a “causal net of events” is more appropriate.

The Haddon matrix analyses injuries according to three phases: the pre-event, event and post-event phases, and three factors: “host” or human, “agent” or processes/equipment, and “environment”. The model can be used for analysing risk factors as well as possible interventions.

Dr Haddon has formulated ten technological strategies for reducing the frequency and consequences of injury. Tested on the Bhopal Gas Leak, “energy” is defined as the toxic gases, and “susceptible structures” are defined as the human beings. Important factors concern the design and the location of the factory, the houses of the inhabitants, information and emergency organisation.

The ten technological strategies also include “the 4 E’s”, that all can be applied on the Bhopal leak. Engineering includes design and maintenance. Environmental modifications is the localisation of the plant. Education of inhabitants, workers and operators, UCIL management as well as the authorities is important. Enforcement includes demands on transnational companies, environmental laws as well as work life laws.

The Berger Model

LR Berger pointed out the limitations of the Haddon matrix: prevention is not emphasised, the social environment is hidden, and it is too complicated (personal communication). He has suggested a new model for prevention, where the pre-event and the event phases are analysed (Fig. 1). The post-event phase was also tested. “Humans” was defined as the different groups of humans involved.

The Logical Framework Approach

The Logical Framework Approach (LFA) is an analytical tool for objectives oriented project planning and management. The key words are objectives oriented, target group oriented and participatory.

The LFA consists of the following parts:Participation analysis, problem and objectives analysis, both visualised as trees, alternatives analysis and developing the LFA matrix (matrices).

The trees of problem and objectives look like chains of events from where there are branches and roots. The matrix makes it possible to clarify what processes/changes from other instances are needed if the project is to succeed. As this is an analysis of an accident that has already happened, the matrix deals with both prevention and management. When planning a project, it may be clearer to create one matrix for prevention and another one or several others for management.

Results of analyses

Analysis according to the LFA Problem Tree (Fig. 2) demonstrates that to create the mega-gas leak, it was not enough that water entered the tank. The most important factors were the plant design and the economic pressures. The same analysis shows that the most important factor for the outcome of the leakage is the negligence of the Union Carbide Corporation and the Governments of India and Madhya Pradesh.

The analyses give the following information (Eckerman 2001, 2004):

The direct cause of the leakage is still unclear. However, the water washing theory seems most convincing.
The direct cause of the leakage is less interesting, as the magnitude of the disaster was dependent on other factors.
The parties responsible for the magnitude of the disaster are the two owners, Union Carbide Corporation and the Government of India, and to some extent the Government of Madhya Pradesh.
The leakage could have been prevented, even if the direct cause was sabotage.
If the personnel management policy had been better, no “disgruntled worker” or “negligent employees” would have existed.
The impact on health could have been reduced if the residents had been given information on how to behave in case of a leakage, and if they had been warned by the siren early in the leakage.
The effects on health caused by the leakage could have been mitigated if the medical, social, and economic rehabilitation had been adequate.
The effects on health caused by the leakage could have been mitigated if the environmental rehabilitation had been adequate.

Conclusions

Models developed for analysis of injuries can be used for analysing a complicated mega accident like the Bhopal gas leak, although different models might stress different aspects.

The Haddon matrix gives us a good picture of the complexity, and gives us many ideas on actions for prevention and management. The Ten Strategies add information on management of a disaster. The 4 E’s tell us about important factors in the society. The Berger model used in this way give us the chance of inventing all different groups of persons involved in the accident. It seems to invite to describe “soft” data, like attitudes and politics.

The Logical Framework Approach (LFA) appears more complete and useful for a complex situation like the Bhopal gas leak. The problem and objectives trees look like chains of event from where there are branches and roots. Visualising causes and consequences in tree models might provide a new understanding. It is obvious that “chain” or “tree” are not the right words. “Net” is more appropriate.

Discussion

Despite thorough knowledge of the Bhopal gas leak, developing the problem tree gave the author some new insights on the connection between causes and effects. When drawing the tree of objectives, the author also acquired some new ideas on the measures necessary to prevent an accident or to mitigate its effects. The matrix makes it possible to clarify what processes/changes from other instances that are needed if the project should succeed. The tree of objectives is much more simple than the tree of problem, indicating that it might be easier to prevent an accident than to mitigate the consequences of it.

References

Berger, L.R. & Mohan, D. (1996). Injury control. A global view. Delhi: OxfordUniversity Press.

Eckerman, I. (2001). Chemical Industry and Public Health. Bhopal as an Example. (MPH 2001:24). Goteborg: NordicSchool of Public Health.

Eckerman, I. (To be published, 2004).The Bhopal Saga. Causes and consequences of the world’s largest industrial disaster. Hyderabad: Universities Press (India) Private Ltd.

The Logical Framework Approach (LFA). Handbook for objective-oriented planning.Oslo: Norad, 1996.

Figures

Figure 1. Matrix ad modum LR Berger.

Figure 2. Problem tree in LFA.