Bhopal study represents “missed opportunity”

Abstract

Nearly three decades on, tragedy continues to unfold in Bhopal, which witnessed the world’s worst chemical and environmental disaster on Dec 3, 1984. The leakage of methyl isocyanate (MIC) and other toxic gases from the pesticide factory of Union Carbide Corporation killed thousands and caused illness in several thousand others. Over the years, survivors of the disaster have been fighting for damages, environmental remediation of the site, and medical rehabilitation. Bhopal presented an opportunity to help survivors and study the longterm eff ects of MIC toxicity in human beings. Now it seems this prospect has been lost forever. The latest report by the Indian Council of Medical Research (ICMR) has revealed that a large percentage of the cohort of the epidemiological study, which includes the only health-monitoring project for gas victims, has been lost. In 1985, ICMR established the Bhopal Gas Disaster Research Centre at the Gandhi Medical College in Madhya Pradesh to initiate a number of studies. Researchers registered a cohort of 80 021 people exposed to MIC in Bhopal, while another cohort of 15 931 people from areas not exposed to MIC served as the control group. However, by the time data collection began in 1986, only 62 706 from the exposed group and 13 526 from the control group, could be contacted. Of them, just 16 860 exposed and 5741 from control areas were actually available in 2010, according to the Technical Report on Population-based Long-term Epidemiological Studies part II (1996–2010) published by ICMR recently. This translates into a cohort loss of 79% in aff ected, and 64% in control, areas over the 25-year period. The report concluded that mortality rates among those exposed to MIC are higher than those in the control group, with respiratory diseases being the most common cause in both the groups. General morbidities among those exposed to MIC continue to be higher than in the control population. Abortion rates have declined in aff ected areas, but no clear pattern has emerged on stillbirths due to scarcity of data. The fi ndings for 1996–2010 are in line with those reported in the fi rst population-based epidemiological study covering the period 1985–94 but released in 2004.