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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: eckerman@algonet.se.


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.


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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.




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Results of analyses
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.

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

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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: Oxford University Press.
Eckerman, I. (2001). Chemical Industry and Public Health. Bhopal as an Example. (MPH 2001:24). Goteborg: Nordic
School 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.




                                                                                                                       4
   Human    Equipment


    Physical Social
environment environment




                          5
     Figure 2. Problem tree in LFA.



                                             PLANT
                                                                                                  ECONOMIC
                                             DESIGN
                                                                                                  PRESS
   Bad main-
   tenance                                               Washing                  UCIL management
                                                         pipelines                not competent
                                     Hazardous
                                     chemicals
                     Storing
                     in large                                                     Operators not
Corroding            tanks
                                                    Water entered                 competent
material
                                                    tank 610


                            Contaminants
                                                                                                            No automatic
                                                        RUN AWAY                  Operator                  alarms
                                                        REACTION                  reacted
                    Safety systems                                                too late
                    not functioning

                                                        Mega gas
                    Safety systems                      leakage                  Many lived
                    under designed                                               close                Location
                                                                                                      of plant

                                                         500,000
                                                                                 No public
             Conflicts                                   persons                                                      Approval of
                                                                                 alarm
             NGO                                         exposed                                                      authorities


      Not enough
      equipment                 Acute                                          No or bad
                                treatment                                      houses
                                inappropriate                                                           Poverty
                                                         Many dead
    Misleading                                                                   No vehicles
                                                         & injured
    information                  Antidote
                                 not tried                                       Not wet cloth
                                                                                 for face
      Conflicts                                                                                             No info
      scientists            Long term                   SURVIVORS                                           before
                            treatment                                          Prolonged
                                                        POORER
                            inappropate                                        exposure
    Health care
    inappropriate                                                                                 No info
                                                                   Economic                       after
                                       Insufficient
                                                                   compensation low
                                       work
                                                                   and delayed
                                       rehabilitation
    Police


                         NEGLIGENCE OF
                         GOVERNMENTS                                        NEGLIGENCE OF
                         OF INDIA & MP                                      UNION CARBIDE
                                                                            CORPORATION



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