Mass Poisoning by Union Carbide and Dow Chemical in Bhopal and India
Exposure to the toxic cloud
On 2-3, December 1984 about 27 tons of Methyl isocyanate [MIC], Mono methyl amine, hydrogen cyanide and other chemicals leaked from a insecticide factory in Bhopal owned by American Multinational Union Carbide Corporation [1]. Based on quantity of the chemical released and area of spread [40 sq. Km.] the Central Water & Air Pollution Control Board estimated MIC concentration to be about 27 ppm, a figure which is about 1400 times that of the OSHA workplace standard of 0.02 ppm for 8 hrs.[2]
Contamination of ground water and soil in Bhopal
Over 20,000 people in the vicinity of the Carbide factory continue to be exposed to heavy metals, volatile organic chemicals, organochlorines, insecticides and other toxic and carcinogenic chemicals. The international environmental organisation, Greenpeace named the area around the factory in Bhopal a “Global toxic hotspot”. [3] A report of the Delhi-based Fact Finding mission on Bhopal released this January shows that the poisons in the ground water are present in high concentrations in the breast milk of women in the affected communities. [4]
Double standards in Dursban
There is very clear evidence that Union Carbide followed double standards of safety in designing and running its Bhopal plant compared with its Institute, West Virginia "sister" plant. Today Dow Chemical Company that inherited the liabilities of Bhopal, following its merger with Union Carbide in February 2001, is pursuing a similar policy of racism in the matter of human safety and health. In June 2000 Dow was forced to withdraw one its main products, Dursban from the American market following a mass of scientific information about this brain damaging chlorpyrifos insecticide [5].
Since October 2000 Dow is promoting Dursban in India as a household chemical "safe for humans and pets" and has set up factories for production of this hazardous chemical.
Health Effects of the December '84 disaster
Mortality
Figures of between 2500 in the immediate aftermath and “more than 8000 in the first three days” are reported by official and independent statistics. A senior UNICEF official, after spending a week investigating conditions in Bhopal shortly after the disaster, commented that many doctors and other health officials privately reported to him that they believed the death toll was around 10,000 [1] .
The current death toll is estimated to be over 20, 000 and counting. Data published by the Department of Relief and Rehabilitation in December 1998 shows over 2000 deaths attributable to exposure in the year 1997 [6]. According to data published in the report of 2001 over 380 deaths in the year 2000 were attributable to exposure [7].
Morbidity
Most studies on the health effects of the disaster have been carried out by the Indian government's research agency - Indian Council of Medical Research ICMR. The ICMR registered a cohort of 80, 021 from a population of 521262 around the plant classified as severe, moderate and mildly exposed based on mortality parameters. An unexposed population was used to select the control group of 15, 391 individuals.[8]
Epidemiological and clinical studies carried out by the ICMR have shown that the toxins crossed in to the blood stream of those exposed and have caused damage to the respiratory, ocular, gastro-intestinal, reproductive, neurological, immunological, psychological and other systems. They have also established that the toxins did indeed cross the placaental barrier leading to faetal poisoning. and caused chromosomal aberrations among those exposed[8]. All of the 24 research projects initiated by the ICMR were wound up (many prematurely) in 1994 and there is no current surveillance of long term health complications. For reasons not stated, research on gynaecological, musculoskeletal, renal, gastrointestinal and endocrinal consequences of exposure to Union Carbide's gases were never taken up by official agencies. There was an ban imposed by the Ministry of Chemical and Petrochemicals on publication of the research findings of ICMR. The ban was lifted in 1996 but the Indian Council of Medical Research is yet to publish its decade-long research on Bhopal victims. July 2001 [9].
Recently published official figures show that the number of patients per day at the government hospitals has remained above 3500 with a decline of less than 5% in the last five years. [7]. Recent reports of six monthly surveys carried out by the Centre for Rehabilitation Studies, an official agency, show that respiratory and ocular morbidity have remained around 4 times and gastro-interstinal morbidity around 3 times higher among the gas exposed population compared to an unexposed one between 1997 and 2001[7] . A paper scheduled to appear in May 22 , 2002 issue of Environmental Health Perspectives [ describes personal exposure and long term health-effects of Union Carbide's gases in Bhopal..
Ocular morbidity
The intensely irritating effect of MIC on the cornea resulted in severe ocular burning, watering, pain and photophobia. Examination showed involvement of the corneal and conjunctival epithelium with redness of the eye, cornea ulceration and lid swelling [10]. Slit lamp examination showed discrete lesions in a band across the interpalpebral area, punctuate keratopathy, conjunctival chemosis and some pigmentary deposition on the cornea [11].
Anderson et. al. performed a survey of exposed and control populations 3 years after the disaster and found photophobia, burning and watering sensation, signs of red eye, superficial interpalpebral erosion, corneal opacity, discharge and fundal changes. Their findings indicated an increased risk of eye infections, hyperresponsive phenomena, excess cataracts and resolution of the corneal erosions in exposed persons. These phenomena have been characterised as the "Bhopal eye syndrome"[12].
Respiratory toxicity
Acute symptoms of the respiratory tract were mainly due to the irritant action of MIC on tissues. Because MIC is moderately soluble in water, lesions were seen in both the upper and lower respiratory tract. Though isocyanates are known to be allergenic in the lung, the respiratory toxicity of MIC appears to be primarily due to its irritant nature [13] .
Follow up studies with lung biopsies done six months after exposure showed evidence of interstitial fibrosis and bronchiolitis obliterans. These findings were similar to those in several animal studies revealing the close association between animal data and clinical findings in Bhopal victims [14] .
Autopsies on 300 victims revealed severe necrotising lesions in the lining of the upper respiratory tract as well as in the bronchioles, alevoli and lung capillaries. Enlarged and oedamatous lungs, consolidation, haemorrhage, bronchopneumonia and acute bronchiolitis were seen [15] .
Reproductive toxicity
Concerns that the gas leak had effects on reproductive health were raised early in 1985 when reports indicated that menstrual cycle disruption, leucorrhoea and dysmenorrhoea had occurred in gas-exposed women [16].
An epidemiological survey by Varma showed pregnancy loss and infant mortality to be very high in gas-exposed women [17] .
NR Bhandari et. al. documented significant increase in spontaneous abortion, perinatal and neonatal mortality in a pregnancy outcome study carried out in 18, 978 households [18].
Fetotoxicity of MIC has been confirmed through animal experiments [19,20,21].
There is recent evidence from Sambhavna Trust, that runs a free clinic for the survivors, that male children born to exposed parents are shorter, weigh much less, have much smaller heads and are much more prone to a host of illnesses than children of unexposed parents [22].
Genotoxicity
Chromosomal studies done two and half months after the gas leak to evaluate genetic damage showed significant increase in number of breaks and gaps in the exposed subjects [23] .
Cytogenetic studies done 3 years after exposure showed higher frequencies of chromosomal aberrations in the exposed group [24].
Immunotoxicity
Immune function was studied in exposed subjects by Saxena et. al. two and half months after exposure [25]. No difference in mean immunoglobulin levels was found when compared to controls. The T-cell population was found to be less than half of that found normally in the Indian population. Significant depression of phagocytic activity of lymphocytes was found as compared to controls.
Psychological and Neuro-behavioural toxicity
Srinivasamurthy and Isaac noted Post-traumatic stress disorder, pathological grief reaction, emotional reactions to physical problems and exacerbation of pre-existing psychiatric problems among gas victims [26].
Neurobehavioural tests were conducted on 350 exposed subjects two and a half months after the accident. Auditory and visual memory, attention response speed and vigilance were found to be significantly impaired [27].
Neuromuscular toxicity
Neuromuscular symptoms in Bhopal survivors have persisted since the gas leak [28]. The symptoms are mainly tingling, numbness, a sensation of pins and needles in the extremities and muscle ache.
Anderson et. al. evaluated the effects of MIC on rat muscle cells in culture [29]. At lower doses, the formation of muscle fibers was prevented. At higher doses, death of fibroblasts and myoblasts was seen.
References
1.Morehouse W, Subramaniam MA. The Bhopal Tragedy : What Really Happened and What it Means for American Workers and Communities at Risk. Council on International & Public Affairs. New York. 1986.
2.Central Water & Air Pollution Control Board Report : Gas Leak Episode at Bhopal. 1985. New Delhi, India.
3.Labunska I, Stephenson A, Brigden K, Stringer R, Santillo D & Johnston P A. The Bhopal Legacy. 1999 Greenpeace Research Laboratories, University of Exeter, UK.

4.Fact Finding Mission on Bhopal. Surviving Bhopal Toxic Present-Toxic Future. 2002, New Delhi, India
5.
6.Dept of Relief & Rehabilitation : Bhopal Gas Tragedy. Govt. of Madhya Pradesh. Relief and Rehabilitation A Report.1989.Bhopal, India.
7.Dept of Relief & Rehabilitation : Bhopal Gas Tragedy. Govt. of Madhya Pradesh. Relief and Rehabilitation A Report. 2001. Bhopal, India.
8.Bhopal Gas Disaster Research Centre [ICMR]. Draft Consolidated Report. 1992. Bhopal, India..
9. Sarangi S. An industrial disaster becomes a medical nightmare. Issues in Medical Ethics, 2001; IX (3): 93.
10. Anderson N, Kerr Muir M, Mehra V, Salmon AG. Exposure and response to methyl isocyanate:results of community - based survey in Bhopal. Br. J Ind Med. 1988;45:469-475.
11.Anderson N, Muir MK, Mehra V. Bhopal Eye. Lancet. 1984;2:1481
12.Anderson N, Ajwani MK, Mahashabde S, Tiwari MK, Kerr Muir M, Mehra V, Ashiru K, Mackenzie CD. Delayed eye and other consequences from exposure to methyl isocyanate: 93% follow up of exposed and unexposed cohorts in Bhopal. Br J Ind Med. 1990;47:553-558.
13.Karol MH, Taskar S, Gangal S, Rubanoff BF, Kamat SR. The antibody response to methyl isocyanate: experimental and clinical findings. Environ Health Perspect. 1987;72:167-173.
14.Boorman GA, Uraih LC, Gupta BN, Bucher JR. Two hour methyl isocyanate inhalation and 90 day recovery study in B6C3F1 mice. Environ Health Perspect. 1987;72:107-114.
15.Indian Council of Medical research. Health effects of exposure to toxic gas at Bhopal: an update on ICMR sponsored researches. Dec 1985.
16.Bang R, Sadgopal M. Effect of Bhopal disaster on women's health - an epidemic of gyanecological diseases [Part I]. 1985. Unpublished data.
17.Varma DR. Epidemiological and experimental studies on the effects of methyl isocyanate on the course of pregnancy. Environ Health Perspect. 1987;72:151-55.
18.Bhandari NR, SyalAK, Kambo I et. al.. Pregnancy outcome survey in women exposed to toxic gas at Bhopal. Ind J Med Res 92:28-33 (1990)
19.Schwetz BA, Adkins B, Jr., Harris M, Moorman M, Sloan R. Methyl Isocyanate: Reproductive and developmental toxicology studies in Swiss mice. Environ Hlth Perspect. 1987;72:147-150.
20.Varma DR, Ferguson J, Alarie Y. Reproductive toxicity of methyl isocyanate in mice. J Toxicol Env Hlth 1987;21:265-275.
21.Varma DR, Guest I, Smith S, Mulay S. Dissociation between maternal and fetal toxicity of methyl isocyanate in mice and rats. J Toxicol Env Hlth. 1990;30:1-14.
22. Sambhavna Trust. Study of growth pattern of young people born in Bhopal between 1982 and 1986. Unpublished report.
23.Saxena AK, Singh KP, Nagle SL, Gupta BN, Ray PK, Srivastav RK, Tewari SP, Singh R. Effect of exposure to toxic gas on the population of Bhopal: Part IV-Immunological and Chromosomal Studies. Ind J Exp Biol. 1988;26:173-176.
24.Ghosh BB, Sengupta S, Roy A, Maity S, Ghosh S, Talukdar G, Sharma A. Cytogenetic Studies in Human Populations Exposed to Gas Leak at Bhopal, India. Environ Hlth Perspect. 1990;86:323-326.
25.Saxena AK, Singh KP, Nagle SL, Gupta BN, Ray PK, Srivastav RK, Tewari SP, Singh R. Effect of exposure to toxic gas on the population of Bhopal: Part IV-Immunological and Chromosomal Studies. Ind J Exp Biol. 1988;26:173-176.
26.Srinivasamurthy R, Isaac MK. Mental health needs of Bhopal disaster victims and training of medical officers in mental health aspects. Ind J Med Res 1987;86(Suppl):51-58.
27.Gupta BN, RastogiSK, Chandra H, MathurAK, Mahendra PN, Pangtey BS, Kumar P, seth RK, Dwivedi RS, Ray PK. Effect of exposure to toxic gas on the population of Bhopal: Part I- Epidemiological, clinical, radiological & behavioural studies. Ind J Exp Biol 1988;26:149-160.
28.Indian Council of Medical Research. Bhopal Gas Disaster Research Centre. Annual report. Bhopal, India. 1991.
29.Anderson D, Goyle S, Philips BJ, Tee A, Beech L, Butler WH. Effect of methyl isocyanate on rat muscle cells in culture. Br J Ind Med 1988;45(4):269-74.
For more information contact:
Dr. Daya Varma < >Dr. Ingrid Eckerman <> Dr. Ramana Dhara <> Dr. Rajiv Bhatia <> Dr. Rosalie Bertell <> or the Sambhavna Clinic . in Bhopal.