A scientific disaster unfolds in Bhopal

The world had lost an opportunity to know long-term toxic effects of Methyl Isocyanate which had leaked from the Union Carbide factory on the night of December 2, 1984, because government research agencies have lost track of a bulk of survivors, says Dinesh C Sharma.

After the gas tragedy three decades ago and the continuing environmental disaster due to toxic waste at the Union Carbide factory site, Bhopal has just witnessed a silent disaster. It is a scientific disaster this time.

The world had lost an opportunity to know long-term toxic effects of Methyl Isocyanate (MIC) which had leaked from the Carbide factory on the night of December 2, 1984, because government research agencies have lost track of a bulk of survivors. These people were part of the only health monitoring and research study in Bhopal since 1985.

The leakage of MIC and other toxic gases from pesticide factory into the atmosphere killed thousands and maimed several thousand others. Over the years, survivors of the disaster have been fighting for damages, environmental remediation of the factory site and medical rehabilitation.

A new report published by the Indian Council of Medical Research has revealed that a bulk of the cohort (group) of the epidemiological study which was initiated right after the disaster has been lost. This means the world will perhaps never be able to get a clearer picture of long-term health impacts of MIC toxicity or fully establish cause-effect relationship of MIC exposure.

The Bhopal Gas Disaster Research Centre was established by ICMR at the Gandhi Medical College to initiate a number of studies to study the effects of the toxic gases, and come up with treatment guidelines to help survivors. The city was divided into two parts based on exposure to gas. A large group of 80,021 persons living in 36 municipal wards exposed to MIC was registered for the study. Another group of 15,931 people from wards not affected served as the comparison or control group. The idea was to monitor the two groups over long-term to see how effects of MIC unfold.

However, by the time data collection began in 1986, only 62,706 from exposed and 13,526 from the control group could be contacted. The numbers further depleted over two decades and only 16,860 exposed and 5,741 from control areas were available in 2010, according to ‘Technical Report on Population-based Long-term Epidemiological Studies part II (1996-2010)’ published by ICMR recently. This means 79 percent of those in the affected group and 64 percent in control group are untraceable.

The report has concluded that mortality rates among MIC affected are higher than those in the control group, with respiratory diseases being the most common cause in both the groups. General illnesses among the gas affected continue to be higher than the control population. Abortion rates have come down in gas-affected areas, but no clear pattern has emerged on still births due to scarcity of data.

The goal of scientific studies was to provide therapeutic relief to victims, but ICMR never published data periodically. Such data could have been crucial in understanding gas-related diseases and developing treatment protocols. The first comprehensive report of ICMR appeared more than two decades years after the disaster (it was published in 2004) and the second one has come after three decades, reducing them to mere academic exercise.

Indian and international experts have slammed ICMR for shoddy research, saying it is not representative of the real health status of survivors and their progenies.

“The purpose of a cohort is to follow subjects wherever they are but this has not been done in Bhopal. This large loss raises the question: what is the health status of those who have moved away? The science is weak because of data quality issues and lack of valid and scientific information on exposure-response,” pointed out Dr V Ramana Dhara, a member of the former International Medical Commission on Bhopal and faculty member at Emory University in Atlanta, US.

Professor Richard W Clapp, an epidemiologist at Boston University, said “the report is unsuccessful in its present form to understand the evolution of late effects of MIC exposure in Bhopal.” However, he said, even the limited findings in the study indicate substantial acute and on-going adverse health impact in those exposed.

Dr Pushpa Mitra Bhargava, eminent biologist and chairman of the Sambhavna Trust which runs a clinic for survivors, said “going by the work being carried out by people in the community research unit of Sambhavna, the cohort loss does not seem to be real. We are fairly certain that the concerned research officials have not exerted themselves in locating exposed families who were part of the cohort.”

ICMR officials explained that though the agency has published the report, it was not responsible for data collected during 1996-2010. The cohort has changed hands three times since 1985. The study started by ICMR in 1985 officially concluded in 1994. In April 1995, the Centre for Rehabilitation Studies of the Bhopal Gas Tragedy Relief and Rehabilitation Department -- a wing of the state government -- was setup and it restarted epidemiological surveys.

The cohort was handed back to ICMR in 2011 when it setup a new outfit called National Institute for Research in Environmental Health in Bhopal. In the period 1993-1995 there was no follow-up at all from any agency.

“ICMR has added insult to the injury by granting legitimacy to a dubious report based on CRS data on the health status of survivors,” felt Satinath Sarangi (Bhopal Group for Information and Action). “We secretly video recorded data collectors of CRS filling up questionnaires on their own without interviewing anyone, while having lunch in a group. They would finish one form in five minutes which would take at least half an hour if administered properly,” Sarangi said.

The report has come under fire ignoring health status of offspring born to second and third generation of MIC-affected and mental health status of the gas-affected. Other studies such as the one published by Sambhavna Clinic showing that in comparison to children of non-exposed parents, children of gas-exposed parents were shorter, lighter, thinner and had smaller heads, have not been cited in the ICMR report.

“On mental illness, unpublished data shows that 80 percent of those diagnosed with a disaster-induced mental illness had not recovered in the last two and half decades,” according to Dr Bhargava.

Dr V K Vijayan, an advisor to ICMR director general, said the study is “primarily a morbidity survey based on symptoms” and may not provide the pattern of diseases that might have occurred due to MIC exposure. “The main drawback of the study is the large number of drop outs with consequential limitations. The information obtained from this study will be useful to plan further studies on organ-specific diseases,” he added. 

“Part of the cohort has been lost due to various reasons like migration, deaths and non-response. Moreover, the data which came to us from the state government was not satisfactory. They did not have technical people,” said Dr Naloke Banerjee (head, NIREH), and lead author of the new report. Migration was a major problem. “For instance, places like railway colony and P&T colony which mainly housed central government employees, gas victims have moved on to other cities. In another affected area, 200 families living in unauthorised housing colony were displaced by the state government,” he adds.

As scientists and government agencies spar, people living around the factory site continue to suffer due to water contamination caused by toxic waste lying at the closed site. Both civil and criminal liability cases in India and the US have not come to a conclusion. The poor victims continue to suffer.

Image: A security guard walks in front of the Union Carbide plant in Bhopal, which in December 1984 developed a toxic gas leak resulting in the death of thousands of people. Photograph: Reinhard Krause/Reuters

Dinesh Sharma is a science journalist and author based in New Delhi.