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 decadelong 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
[http://ehpnet1.niehs.nih.gov/docs/2002/110p487-500dhara/abstract.html] 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 gasexposed 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
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for American Workers and Communities at Risk. Council on International & Public Affairs. New York.
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2.
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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.
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http://www.nrdc.org/health/pesticides/bdursban.asp
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Rehabilitation A Report.1989.Bhopal, India.
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Rehabilitation A Report. 2001. Bhopal, India.
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isocyanate:results of community - based survey in Bhopal. Br. J Ind Med. 1988;45:469-475.
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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.
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15. Indian Council of Medical research. Health effects of exposure to toxic gas at Bhopal: an update on
ICMR sponsored researches. Dec 1985.
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diseases [Part I]. 1985. Unpublished data.
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22.
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exposure to toxic gas on the population of Bhopal: Part IV-Immunological and Chromosomal Studies. Ind J
Exp Biol. 1988;26:173-176.
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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, Rastogi SK, Chandra H, Mathur AK, 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,
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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 < dvarma@pharma.mcgill.ca >Dr. Ingrid Eckerman <eckerman@algonet.se> Dr.
Ramana Dhara <Ramana.Dhara@HCAHealthcare.com> Dr. Rajiv Bhatia <rajiv_bhatia@dph.sf.ca.us> Dr.
Rosalie Bertell <rosalie.bertell@verizon.net> or the Sambhavna Clinic sambavna@sancharnet.in. in
Bhopal.