Bhopal, India


During the night of December 3, 1984, one of the world's worst industrial accidents occurred in Bhopal, India, a city of about one million people. The Bhopal disaster involved a leak of the toxic gas methyl isocyanate gas and other chemicals at the Union Carbide India pesticide plant. Hundreds of thousands of people were exposed to the toxic substances. Along with Three Mile Island and Chernobyl, Bhopal is an example of the dangers of industrial development without proper attention to environmental health and safety.


A large industrial and urban center in the state of Madhya Pradesh, Bhopal was the location of a plant owned by the American chemical corporation Union Carbide and its Indian subsidiary Union Carbide India. The plant manufactured pesticides, primarily the pesticide carbaryl (marketed under the name Sevin), which is one of the most widely used carbamate-class pesticides in the United States and throughout the world. Among the intermediate chemical compounds used together to manufacture Sevin is methyl isocyanate (MIC)—a lethal substance that is reactive, toxic, volatile, and flammable. It was the uncontrolled release of MIC from a storage tank in the Bhopal facility that caused the deaths of many thousands of people.

The poisonous cloud of MIC released from the plant was carried by the prevailing winds to the south and east of the city—an area populated by highly congested communities of poorer people, many of whom worked as laborers at the Union Carbide plant and other nearby industrial facilities. Released at night, the cloud went undetected by residents who remained asleep in their homes, thus possibly ensuring a maximal degree of exposure. Many hundreds died in their sleep, while others choked to death on the streets as they ran out in hopes of escaping the lethal cloud. Thousands more died in the following days and weeks. The Indian government and numerous volunteer agencies organized a massive relief effort in the immediate aftermath of the disaster consisting of emergency medical treatment, hospital facilities, and supplies of food and water. Medical treatment was often ineffective, for doctors had an incomplete knowledge of the toxicity of MIC and the appropriate course of action.

In the weeks following the accident, the financial, legal, and political consequences of the disaster unfolded. In the United States, Union Carbide stock dipped 25 percent in the week immediately following the event. Union Carbide India accepted responsibility for the accident, arranging some interim financial compensation for victims and their families. However, its parent company, Union Carbide, which owned 50.9 percent of UCIL, refused to accept any legal responsibility for its subsidiary. The Indian government and hundreds of lawyers on both sides pondered issues of liability and the question of a settlement. While Union Carbide hoped for out-of-court settlements or lawsuits in the Indian courts, the Indian government ultimately decided to pursue class action suits on behalf of the victims in U.S. courts in the hope of larger settlements. However, the U.S. courts refused to hear the case, and it was transferred to the Indian court system.

Bhopal gas tragedy survivors hold placards during a protest in New Delhi, India, Monday, Nov. 10, 2014.

Bhopal gas tragedy survivors hold placards during a protest in New Delhi, India, Monday, Nov. 10, 2014. The survivors commenced an indefinite hunger strike in the capital demanding additional compensation for those affected and revision of casualty figures after 30 years of suffering. Activists say that thousands of children, born to parents directly exposed to the gas leak or poisoned by the contaminated water, are suffering from cleft lips, missing palates, twisted limbs.
(AP Photo/Tsering Topgyal)


The actual number who died from the Bhopal disaster may never be known, as various organizations and commissions have arrived at different figures. The best estimates (as of 2010) were that, of the more than 200,000 persons exposed to the lethal gas cloud of MIC, around 3,800 people died, with many more thousands dying in the coming days, weeks, and months. Numerous buffaloes, cows, dogs, and birds also died. By 1994, the human death toll was estimated at more than 6,000, and by 2002, the estimate was between 15,000 and 20,000. Most of the later deaths were attributed to respiratory complications. Over 100,000 people were seriously injured. Many observers argue that the figures cited above are underestimates of the actual numbers of persons harmed or killed by the release.

Causes and symptoms

MIC (CH3-N=C=O) is highly volatile and has a boiling point of 89°F (39.1°C). In the presence of trace amounts of impurities such as water or metals, MIC reacts to generate heat, and if the heat is not removed, the chemical begins to boil. If relief valves, cooling systems, and other safety devices fail to operate in a closed storage tank, the pressure and heat generated may be sufficient to cause a release of MIC into the atmosphere. Because the vapor is twice as heavy as air, the vapors, if released, remain close to the ground where they can do the most damage, drifting along prevailing wind patterns. As set by the United States Occupational Health and Safety Administration (OSHA), the standards for exposure to MIC are set at 0.02 ppm over an eight-hour period. The immediate effects of exposure, inhalation, and ingestion of MIC at high concentrations (above 2 ppm) are burning and tearing of the eyes, coughing, vomiting, blindness, massive trauma of the gastrointestinal tract, clogging of the lungs, and suffocation of bronchial tubes. In cases that are not immediately fatal, the longterm health consequences include permanent blindness, permanently impaired lung functioning, corneal ulcers, skin damage, and potential birth defects.


Limited healthcare resources and information were available for many of those affected by the toxic gas release. There was also a general lack of experience in the medical community in dealing with a disaster of this type and magnitude, or specifically, with treatment of persons exposed to MIC. However, Union Carbide did send an international team of medical experts to assist and provided medical equipment and supplies. The company also paid for Indian medical experts to attend meetings on research and treatment for victims.

Short-term health effects that required treatment included acute irritant effects on the eyes and respiratory tract. Significant neurological, reproductive, neurobehavioral, and psychological effects were observed over the long term. Psychological problems included, and continued to include, posttraumatic stress disorder, pathological grief reactions, emotional reactions to physical problems, and exacerbation of preexisting psychiatric problems. Damaged organs were also more susceptible to other environmental effects, such as infections, irritants, and allergens. Pulmonary lung damage prevented survivors working in jobs requiring moderate or strenuous activity.

Public health role and response

The public health infrastructure was weak in Bhopal in 1984. Tap water was available for only a few hours a day and was of poor quality. There was no functioning sewage system, and untreated human waste was disposed of into two nearby lakes, one of which was a source of drinking water. The city had four major hospitals but there was a shortage of physicians and hospital beds. There was also no mass casualty emergency response system in place in the city. The failure of the public healthcare system contributed to the disaster. There were no established treatment protocols, and doctors treated only superficial symptoms. Wide use of steroids, antibiotics, and psychotropic drugs added to the damage caused by the gas exposure. Patients also had to deal with an often corrupt and insensitive staff at overcrowded, under-equipped, and unsanitary hospitals. Although millions of rupees were spent on care, the health of the survivors and their children continued to be adversely affected.

The disaster at Bhopal raises a number of critical issues and highlights the differences between developed and developing countries in regard to design and maintenance standards for health and safety. Management decisions allowed the Bhopal plant to operate in an unsafe manner and for a shantytown to develop around its perimeter without appropriate emergency planning. The Indian government, like those of many other developing nations in need of foreign investment, appeared to sacrifice worker safety in order to attract and keep Union Carbide and other industries within its borders. While a number of environmental and occupational health and safety standards existed in India before the accident, their inspection and enforcement was cursory or nonexistent. Often understaffed, the responsible Indian regulatory agencies were rife with corruption as well. The Bhopal disaster also raised questions concerning the moral and legal responsibilities of American companies abroad, and the willingness of those corporations to apply stringent U.S. safety and environmental standards to their operations in the Third World despite the relatively free hand given them by local governments.


Although worldwide shock at the Bhopal accident faded, the suffering of many victims continued. In response to these continuing health effects, the Supreme Court of India in August 2012 ordered steps to be taken to ensure better health care for the victims. In issuing the order, the Court stated: The magnitude and extent of adverse impact on the financial soundness, social health and upbringing of younger generation, including progenies, may have been beyond human expectations. In such situations and where the laws are silent or are inadequate, the courts have unexceptionally stepped in to bridge the gaps.

While many national and international safeguards on the manufacture and handling of hazardous chemicals have been instituted, few expect that lasting improvements will occur in developing countries without a gradual recognition of the economic and political values of stringent health and safety standards.


In order to prevent such a disaster from occurring again, national governments and international agencies need to focus on corporate responsibility and accident prevention in the developing world as is done in advanced industrial nations. Specifically, prevention should include risk reduction in plant location and design and safety legislation and procedures. Local governments should not allow hazardous industrial facilities to be situated within urban areas. Industry and government need to provide financial support to local communities so they can provide medical and other necessary services to reduce morbidity, mortality and material loss in the case of industrial accidents. Existing public health infrastructure needs to be taken into account and improved as necessary when hazardous industries choose sites for manufacturing plants. Future management of industrial development requires that appropriate resources be devoted to advance planning before any disaster occurs. Communities that do not possess infrastructure and technical expertise to respond adequately to such industrial accidents should not be chosen as sites for hazardous industries.

See also Chemical poisoning .

Capital of the Indian state of Madhya Pradesh and the administrative headquarters of Bhopal District and Bhopal Division.
Madhya Pradesh—
State in central India. Its capital is Bhopal.
Methyl isocyanate (MIC)—
An organic compound is an intermediate chemical in the production of carbamate pesticides (such as carbaryl, carbofuran, methomyl, and aldicarb). Exposure symptoms include coughing; chest pain; Dyspnea; asthma; irritation of the eyes, nose and throat; and skin damage. Higher levels of exposure can result in pulmonary or lung edema, emphysema and hemorrhages, bronchial pneumonia, and death.



Amnesty International. Clouds of Injustice: Bhopal Disaster 20 Years On. Arlington, VA: Apex Press, 2004.

Eckerman, Ingrid. The Bhopal Saga: Causes and Consequences of the World's Largest Industrial Disaster. Arlington, VA: Apex Press, 2005.

Hanna, Bridget, Ward Morehouse, and Satinath Sarangi. The Bhopal Reader: Remembering Twenty Years of the World's Worst Industrial Disaster. Arlington, VA: Apex Press, 2005.


World Health Organization, Avenue Appia 20, 1211 Geneva 27, Switzerland, 2241 791 21 11, Fax: 2241 791 31 11,, .

Usha Vadagiri
Revised by Judith L. Sims

  This information is not a tool for self-diagnosis or a substitute for professional care.