CALAMITY AT BHOPAL

Bhopal was the site of the world’s worst industrial disaster, when on December 3, 1984, nearly 40 metric tons of methyl isocyanate (MIC) leaked from the Union Carbide pesticide plant and, being heavier than air, MIC settled on the ground. MIC is the smallest and most toxic of all isocyanates; it affected all life forms, killed nearly 8000 people within 48 hours by causing pulmonary edema, and produced lasting effects on more than 200,000 residents. There is no antidote against MIC, although sodium thiosulfate was administered in the mistaken belief that the culprit chemical was hydrogen cyanide. Studies done on experimental animals after the accident largely confirm what was observed on the Bhopal population. Nearly 40% of women pregnant at the time of the disaster lost their fetuses. Chronic effects include pulmonary, gynecological, ocular, neurological, and other complications. MIC metabolites are also toxic and some, like trimethylamine, exert selective toxicity on male progeny. Large quantities of highly toxic chemical waste stored in the factory premises have contaminated the soil and water. The Bhopal disaster revealed dangers inherent in chemical industries and the need for stringent regulations and supervision to ensure safety.

Bhopal was the site of the world’s worst industrial disaster, when on December 3, 1984 nearly 40 metric tons of methyl isocyanate (MIC) leaked from the Union Carbide Pesticide Plant and being heavier than air MIC settled on the ground. MIC is the smallest and the most toxic of all isocyanates; it affected all life forms, killed nearly 8,000 people within 48 hours by producing pulmonary edema, and produced lasting effects on more than 200,000 residents. There is no antidote against MIC although sodium thiosulfate was administered in the mistaken belief that the culprit chemical was hydrogen cyanide. Studies done on experimental animals after the accident largely confirm what was observed on the Bhopal population. Nearly 40% of women pregnant at the time of the disaster lost their fetuses. Chronic effects include pulmonary, gynecological, ocular, neurological and other complications. MIC metabolites are also toxic and some like trimethylamine exert selective toxicity on male progeny. Large quantities of highly toxic chemical waste stored in the factory premises have contaminated the soil and water. The Bhopal disaster revealed dangers inherent in chemical industries and the need of stringent regulations and supervision to ensure safety.

The European Union (EU) Decision (1082/2013/EU) on serious cross border threats to health was adopted by the European Parliament in November 2013, in recognition of the need to strengthen the capacity of Member States to coordinate the public health response to cross border threats, whether from biological, chemical, environmental events or events which have an unknown origin. Although mechanisms have been in place for years for reporting cross border health threats from communicable diseases, this has not been the case for incidents involving chemicals and/or environmental events. A variety of collaborative EU projects have been funded over the past 10 years through the Health Programme to address gaps in knowledge on health security and to improve resilience and response to major incidents involving chemicals. This paper looks at the EU Health Programme that underpins recent research activities to address gaps in resilience, planning, responding to and recovering from a cross border chemical incident. It also looks at how the outputs from the research programme will contribute to improving public health management of transnational incidents that have the potential to overwhelm national capabilities, putting this into context with the new requirements as the Decision on serious cross border threats to health as well as highlighting areas for future development.

The chapter discusses acute and chronic toxicities of methyl isocyanate (MIC), and the possible mechanisms. The effect of the accident on the environment, the consequences of consuming polluted underground water, the cause of the accident, legal aspects of the tragedy, and the issues of compensation and rehabilitation of the population are extremely important. The chemistry and toxicity of MIC are studied in relation to other members of the isocyanate family, all of which are toxic. The cyanide-sodium thiosulfate controversy is also briefly discussed. The exposure of Bhopal population to MIC caused thousands of deaths and long-term effects of varying severity. Although chemically-induced acute-respiratory-distress syndrome was probably the cause of deaths, the magnitude and the underlying mechanisms of long-term effects with the exception of pulmonary complications have yet to be identified. Animal studies corroborate some of the clinical findings, but they neither offer an explanation nor disclose the underlying mechanism of long-term effects. It is safe to say that the full dimension of the toxicity of a chemical (and also its therapeutic potential) cannot be predicted from its chemical structure, but can be approximated by careful and painstaking studies. Such an enquiry into MIC would be well deserved not because it will disclose an astounding rational therapeutic approach, but because it will be a fitting conclusion to the speculative assertions one way or another.

The chapter discusses acute and chronic toxicities of methyl isocyanate (MIC), and the possible mechanisms. The effect of the accident on the environment, the consequences of consuming polluted underground water, the cause of the accident, legal aspects of the tragedy, and the issues of compensation and rehabilitation of the population are extremely important. The chemistry and toxicity of MIC are studied in relation to other members of the isocyanate family, all of which are toxic. The cyanide-sodium thiosulfate controversy is also briefly discussed. The exposure of Bhopal population to MIC caused thousands of deaths and long-term effects of varying severity. Although chemically-induced acute-respiratory-distress syndrome was probably the cause of deaths, the magnitude and the underlying mechanisms of long-term effects with the exception of pulmonary complications have yet to be identified. Animal studies corroborate some of the clinical findings, but they neither offer an explanation nor disclose the underlying mechanism of long-term effects. It is safe to say that the full dimension of the toxicity of a chemical (and also its therapeutic potential) cannot be predicted from its chemical structure, but can be approximated by careful and painstaking studies. Such an enquiry into MIC would be well deserved not because it will disclose an astounding rational therapeutic approach, but because it will be a fitting conclusion to the speculative assertions one way or another.