Union Carbide’s Chemical Trail

Bhopal gas disaster second disaster photographer David Graham

Poona Bai and her son Raj. Raj cannot walk and has been visually impaired since birth. Photo by David Graham.

Thousands of families in Bhopal have been drinking water contaminated with pesticides, chlorinated organic compounds, and heavy metals for decades.

Union Carbide’s US managers were aware of the danger of groundwater pollution from the factory in Bhopal. According to the leader of one of the survivors’ organisations, Rashida Bee:

‘As early as 1972, they had discussed various proposals to stop it happening – but they ignored all of them. Instead, knowing the dangers, they okayed the dumping of thousands of tons of solid and liquid chemical waste in and outside the factory. They knew it would poison our water and our daily lives and they did it anyway.’

Suspicions that chemicals were leaking from the factory began in 1980 when cattle in fields nearby began to die. Union Carbide denied responsibility but paid compensation to the animals’ owners. After the gas leak of December 1984, the factory was closed, but the corporation made no attempt to remove the huge stocks of lethal pesticides.

In 1989, increasing criticism from local community leaders, activists and the Bhopal media, all of whom by now believed that the factory was causing illness, led Union Carbide to conduct a secret investigation. The company found that soil and water within the site were massively contaminated. Samples taken close to the factory wall caused 100% toxicity in fish. On the other side of the wall was the community of Atal Ayub Nagar, but Union Carbide chose to keep its findings secret. The study was not released to the public and Union Carbide never warned local people that their drinking supplies were poisoned. Union Carbide hid its study from public view.

A later 1997 study, commissioned by Union Carbide from Arthur D. Little, warned that pollution of the underground aquifer (which feeds local drinking water wells) could be happening at a rate far faster than imagined. Still Union Carbide kept silent and did not warn people. It was not until 1999 – a full ten years after Carbide’s initial investigation – that a Greenpeace report revealed the full extent of the poisoning, discovering severe contamination of the factory site, surrounding land and groundwater. Levels of mercury in some places were 6,000,000 times higher than background levels. Drinking water wells near the factory used by local people were heavily polluted with chemicals known to produce cancers and genetic birth defects.

Residents who live near the abandoned Union Carbide factory in Bhopal collect water from a contaminated hand pump. Photo by David Graham.

Residents who live near the abandoned Union Carbide factory in Bhopal collect water from a contaminated hand pump. Photo by David Graham.

A 2002 study by the Fact-Finding Mission on Bhopal, found lead, mercury and organochlorines in the breastmilk of nursing mothers. Many of the chemicals found in the water are hydrophobic. One they are in the system they can only leave through the placenta or through breast milk.

Survivors’ organisations highlight the need for medical assessment, monitoring and treatment of those affected by the contamination, and due compensation for those whose health and livelihoods have been damaged by this second attack by Union Carbide on their lives.


‘Toxic groundwater – Bhopal’s Second Disaster’

Initially, while the Union Carbide factory was in production, toxic waste was simply dumped, in unlined pits, throughout the factory site but, when space became limited, it was pumped out as liquid effluent,to three specially constructed ‘solar evaporation ponds’ (SEP’s) beyond the factory perimeter on land belonging to local government, the Bhopal Municipal Corporation (BMC),. But, in a Union Carbide Corporation internal telex of 25 March 1982, the SEP’s were reported to have ‘almost emptied’ through lining leakage2.

Although pesticide production in the plant stopped, after the disaster, the plant was never fully dismantled, the site was not cleaned up, and the SEP’s were simply abandoned. Chemicals were stored, un-sheltered, on-site for decades and these chemicals have leached through the soil and into the groundwater. The toxic contamination of the soil, and particularly the groundwater, in the surrounding communities, emanating from the on-site waste and the long derelict SEP’s, is believed to be the cause of many severe health problems among the residents of these poor communities.


The faulty valve from the MIC plant in the abandoned Union Carbide factory. Photo by David Graham.

“It is not a case of ‘acute toxicity’, but of ‘chronic toxicity’. The toxic wastes were dumped by the factory when it was functional between the late Seventies and 1984, and when it was shut after the gas leak. These have contaminated the (ground)water,” The Centre for Science and Environment, India, director Sunita Narain.

Contamination history
Groundwater contamination has been documented in the area around the UCIL site, by NGOs and governmental organisations4. Greenpeace (1999, 2002 & 2004) conducted three studies and found that groundwater, in the vicinity of the UCIL plant, was highly contaminated with toxic chemicals. The Madhya Pradesh Pollution Control Board (MPPCB) has monitored the groundwater quality for years and analysed water samples from different communities located close to the UCIL plant. The MPPCB found toxic chemicals greatly exceeding both World Health Organisation (WHO) and National Environmental Protection Agency (EPA) drinking water guideline values. Furthermore, Srishti (2002) analysed water samples from seven communities around the UCIL plant and reported the presence of several contaminants also exceeding WHO & EPA guidelines.

A boy stands by a hole in her wall surrounding the derelict Union Carbide factory in Bhopal. Photo by David Graham

A boy stands by a hole in her wall surrounding the derelict Union Carbide factory in Bhopal. Photo by David Graham

The National Environmental Engineering Institute (NEERI), Nagpur, India, carried out a study in 1990, at the behest of the State Government of Madhya Pradesh to investigate the pollution caused by the SEP’s. The study included the investigation of climatic, geological and hydrogeological (surface waters and groundwater flow) settings of the area on which the SEP is located. Furthermore, an assessment of the water quality and the soil contamination around the SEP was conducted by testing water and soil samples for several chemicals.

Most of the chemicals found in these studies are chlorinated organic compounds and are known to potentially cause adverse health effects on humans. Besides carbon tetrachloride, dichlorobenzenes, trichlorobenzenes, and chloroform, a variety of other chemicals and heavy metals, have been identified. All of these chemicals were used in manufacturing processes at the UCIL pesticide plant.

The contamination today
In 2009, two further studies were released which drew a more up-to-date picture of the contamination, one by the Bhopal Medical (BMA) Appeal, on behalf of the Sambhavna Trust Clinic in Bhopal; and the other by the Pollution Monitoring Laboratory (PML) of The Centre for Science and Environment (CSE), a non-governmental organization based in New Delhi.


Residents of slums close to the factory gather water which is heavily contaminated with heavy metals and toxins. Photo by David Graham

Residents of slums close to the factory gather water which is heavily contaminated with heavy metals and toxins. Photo by David Graham

BMA Study
The BMA targeted chemicals that had already been identified in previous studies by Greenpeace et al, and specifically focused on the water issues. It looked at the  contamination problem but also included a full survey of the water supply situation to the communities including the provision of water, from alternative sources, by the BMC.

The Supreme Court of India passed a ruling, in 2004, ordering that a safe water system must be supplied to the affected communities and the BMC was charged with the task of carrying out this order. But, the BMA found that the amount of water supplied was insufficient in most of the fifteen communities investigated5. Many thousands of residents do not have enough clean water for drinking, washing and cooking. Households without private hand pumps are highly dependent on the water supplied by the BMC. However, the water supply system, where it has been installed by the BMC, is in very poor condition. Plastic water tanks are often broken and are not being cleaned on the inside, promoting algal and microbial growth. Water supply, by tanker trucks, is highly irregular and residents are forced to resort to the contaminated supply from the hand pumps.

The BMA’s sampling campaign confirmed the presence of organochlorine compounds in quantities massively exceeding WHO & EPA drinking water guidelines. Chloroform concentrations exceeded guideline values by a factor of between 4 and 7 times and carbon tetrachloride between 900 and 2400 times. The study also found at least 15 other highly toxic chemicals present in the drinking water samples, at levels that greatly exceeding the WHO safety guidelines, and further chemicals present for which there are no safe guideline values.

Due to the small sample size the report did not draw conclusions regarding the spatial distribution of the groundwater contamination. However, comparison with the previously compiled data proves that the pollutant load of the groundwater has remained high, and in some cases substantially increased, throughout the past decade, posing a health threat to residents through chronic exposure.

Table 1: Chemical concentration (ug/L) in water samples as tested by BMA from one hand pump on two dates.

Hand Pump AA1(Atal Ayub Nagar) Chloroform Carbon tetrachloride 1,2,3-Trichlorobenzene
UK lab(July 2009) 266 4880
Swiss lab(May 2008) 148 1790 17
WHO guidelines 300 2 20
EPA Guidelines 70 5

The BMA report does conclude, from the samples taken in one particular community, that:

“The hand pumps in Atal Ayub Nagar should be shut down immediately as the water is a health hazard for the residents. The water should not even be used for washing as the concentration of solvents present may cause skin problems6.”

CSE Study
The CSE studied the chemistry of the processes used for producing pesticides, at the UCIL site, and selected four groups of chemicals for testing in soil and water samples.  It tested for chlorinated benzene compounds: 1,2 dichlorobenzene; 1,3 dichlorobenzene; 1,4 dichlorobenzene; and 1,2,3 trichlorobenzene. It also tested for: organochlorine pesticides alpha, beta, gamma and delta hexachlorocyclohexane (HCH); five heavy metals lead, cadmium, chromium, mercury, arsenic; and the two main products of UCIL carbaryl (Sevin) and aldicarb (Temik)- both largely produced for cotton cropping systems.

CSE tested one stored waste sample, six soil samples and one surface water sample from within the UCIL site and one soil sample from the solar evaporation pond. These tests clearly show that the land within the UCIL factory and around the SEP’s is highly contaminated with pesticides, chlorinated benzenes and heavy metals7.

The CSE also tested groundwater samples taken from various communities around the UCIL site. It found that the concentration of pesticides found in all water samples were between 1.1 to 59.3 times the only mandatory water standard in India, fixed by the Bureau of Indian Standard (IS:14543). The average concentration in all groundwater samples tested, including those up to 3.5km from the factory site, was 0.006 ppm, which is 12 times the standard.

CSE also found that:
• The waste stored within the UCIL premises had all chlorinated benzene compounds and all organochlorine pesticides tested for by the PML. The total pesticide concentration in the waste sample was as high as 9867 ppm (parts per million).

• The soil samples contained all chlorinated benzene compounds and organochlorine pesticides. It also had four out of five heavy metal tested by PML.

• The profile of chemicals found within the UCIL factory and in the waste disposal site of UCIL matches the chemicals found in the groundwater sample in the colonies outside the factory premises. There is no other source of these chlorinated benzene compounds and pesticides than UCIL. The topography of the area also points towards contamination of the groundwater due to the UCIL. The plant is located at a slightly higher altitude than the residential colonies with a gently sloping terrain. (implying that the water flows in that direction).

• Carbamate pesticides, as a general group, are considered to be moderately persistent in the environment. But finding carbamates in groundwater, 25 years since the plant shut down, clearly means that the UCIL plant is acting as a continuous source of groundwater contamination8.

For a summary of health effects, on the human body, of the various chemicals and heavy metals found in BMA/ CSE tests, please refer to: ‘Contamination of soil and water inside and outside the Union Carbide India Limited, Bhopal’. Centre For Science and Environment, December 2009 & ‘The Bhopal Legacy: Toxic contaminants at the former Union Carbide factory site, Bhopal, India’: 15 years after the Bhopal accident.’ Greenpeace Research Laboratories, 1999.

Women collecting water from a standpipe in the street in Bhopal. Photo by David Graham

Women collecting water from a standpipe in the street in Bhopal. Photo by David Graham

Indian Institue of Toxicological Research

In 2018 the Indian Institute of Toxicology Research (IITR) submitted a report to the apex committee of the Supreme Court confirming excessive levels of nitrate, chloride and heavy metals in 20 further colonies, bringing to 42 the number with groundwater contaminated by chemicals believed to have originated from toxic waste dumped by Union Carbide. Thousands of people remain using this groundwater as their primary supply.

The report indicated the presence of alpha naphthol in the samples and according to the petitioner in the matter, Bhopal Group for Information and Action (BGIA), this vindicates the assumption that toxic waste, dumped by Union Carbide, is the source of the contamination.

The Indian Institute of Toxicology Research (IITR) Report, Analysis of Drinking Water Samples From Bhopal (Ground Water Samples). 12 June 2018.

The politics of clean up
The Dow Chemical Company purchased Union Carbide in 2001, thereby inheriting both the assets, and the liabilities, of the Union Carbide Corporation. The Union Carbide Corporation (UCC) were the controlling shareholder, with a 50.9% stake, of UCIL but Dow refuse to accept any responsibility for the disaster in Bhopal. Dow have repeatedly stated, in the media and elsewhere, that the Union Carbide Corporation (UCC) and Union Carbide India Limited (UCIL) settled their liability for the gas release tragedy with the Government of India in 1989 with a payment of $470 million. Whilst this is true, it must be noted that this settlement does not, and never has, covered any liabilities arising from subsequent and continued contamination or the contamination of the groundwater.

Warren Anderson, chairman of UCC at the time of the disaster and, along with UCC, the prime accused in the criminal case of culpable homicide, retired into a life of luxury. He spent his time between homes in Florida and the Hamptons, in Upper State New York, before his death in September 2014.  He never faced trial.

Documents obtained from the US State Department under the Freedom of Information Act, are most revealing. A letter to the State Department review authority Archie M. Bolster (dated 24 July, 2003), from a US industry representative, stated, “the request to extradite Warren Anderson should be rejected. No issue has greater potential to destroy US business leaders’ confidence in India than the handling of the Warren Anderson case.” In August 2009, when the Chief Judicial Magistrate issued a second non-bailable warrant against Warren Anderson, the people of Bhopal spilled on to the streets to celebrate.

Union Carbide and Dow were allowed to get away with it because of the international legal structures that protect multinationals from liability. Union Carbide sold its Indian subsidiary and pulled out of India. Warren Anderson, the Union Carbide chief executive at the time of the gas leak, lives in luxurious exile in the Hamptons, even though there’s an international arrest warrant out for him for culpable homicide. The Indian government has yet to pursue an extradition request. Imagine if an Indian chief executive had jumped bail for causing an industrial disaster that killed tens of thousands of Americans. What are the chances he’d be sunning himself in Goa9?

Despite Dow’s continuing refusal to accept any responsibility for cleaning up the site there is a belief that India’s government wants to end the current impasse in Bhopal. Partly for humanitarian reasons but also, it is believed, to allow Dow to expand investments currently curtailed, and under attack, by activists. Dow had been asked by the Indian Government to deposit a sum of $22 million against remediation costs, pending a hearing in the Madhya Pradesh High Court but, in November 2006, Dow Chairman, Andrew Liveris, wrote to Ronen Sen, Indian Ambassador to the US suggesting that this position was “adverse to the company”. He requested the Government of India to withdraw the application in return for “economic growth in India, including key foreign investments that will promote job creation”.

For their part, the campaigners have appealed to the Government in Delhi to establish an ‘empowered commission’ to co-ordinate progress in the legal case and the clean-up. The Commission would be empowered to allocate resources to different rehabilitation schemes, or research projects, issue tenders, identify and implement Central or State Government agencies, and change the agencies, all without recourse back to central government. But the Madhya Pradesh state government is resisting Delhi’s attempts to set up any such commission despite the Central Government announcing the establishment of such a commission in August 2008.

Satinath Sarangi, managing trustee of the Sambhavna Clinic, which treats survivors in Bhopal, believes that part of the problem is Dow’s refusal to formally accept responsibility for what Union Carbide allowed to happen and that a “compromise could be reached” if Dow made provision for health damages and monitoring of patients, and agreed to clean up the site and surrounding areas, which it is still resisting. “That would be some sort of compromise that we would consider”, he said10.


Children play cricket within the grounds of the abandoned factory

Where now
The Central Pollution Control Board (CPCB), Government of India, has also been testing the groundwater and, although their report is not yet officially published, despite being expected for some months, it is believed that their tests produced results largely concurring with the BMA/ CSE reports. However, CPCP Chairman SP Gautum said “I am not aware if the results of the research conducted on the collected samples are out,” But, according to The Hindu (newspaper): “Reliable sources, on condition of anonymity, said that since the CPCB findings confirm contamination, it intends to sit on it or it would cause embarrassment to the Union Government and the Ministry of Environment and Forests, which has been denying contamination11.”

By any credible reckoning the groundwater contamination in Bhopal has to be accepted as fact and the forthcoming CPCP report may prove something of a litmus test. But, even if the contamination is accepted, the question still remains as to who will pay for the clean up? Dow, despite purchasing Union Carbide, along with all of its assets and liabilities, still refuses to acknowledge responsibility and there is plenty of evidence of political pressure to dilute its liabilities.

“This cannot be acceptable… The toxins we have found in the factory are related to the production process of the plant. It is clear that UCIL was dumping its waste – of chemicals and pesticides – in the factory compound over the years it operated the factory. Dow must be held responsible. “Its own annual report shows that it has taken on the liability of Union Carbide in the case of asbestos exposure in the US. Why is it denying this responsibility in India?” CSE, India, director Sunita Narain.

Practically speaking, the recent reports produced some potentially extremely worrying results. The assumption, up to now, has been that perhaps 30,000 people are affected by the water contamination in Bhopal. But it must now be considered a far greater problem.

Numbers of affected people have largely been based on the data of tests that are anything up to a decade old. The new reports show two very interesting things:

The contamination levels are increasing over time. When a comparative analysis is made of test results from the same borehole, which was possible with the BMA tests, (one particular well was tested twice by the BMA and once by the BBC over a period of nearly 18 months) the ingress of toxins appears to be increasing over time. Given the large amounts of toxic waste in the area this is not altogether surprising.

The contamination has gone much further into the aquifer than anybody has previously estimated. This assumption is based on two pieces of evidence. Firstly, that the results of the CSE tests showed the greatest pesticide contamination, in ground water samples, at Shiv Nagar a distance of 3.5km to the North East of the UCIL site. Analysis of the aquifer, by NEERI, suggested that the plume would flow at a rate of between 2-300 metres per annum and the report, along with anecdotal evidence, seems to suggest the plume travelling in a North to Northeasterly direction. Taking this into account it is not surprising that the toxic plume has reached Shiv Nagar but what is more worrying is the level of toxicity as this suggests that the plume has travelled well beyond Shiv Nagar and much further than any previous estimates suggest. More worryingly still is the fact that the CSE report also found extremely high levels of pesticides in the ground water at New Arif Nagar which is North-North-West of the UCIL site.

Taking both of these facts into consideration seems to suggest that the groundwater contamination is in fact much wider spread than any previous estimation. On that basis the number of people being affected by this toxic supply must be massively in excess of the previous estimate of 30,000.

This toxic contamination of the ground water is Bhopal’s ‘Second Disaster”.


1: These numbers are open to debate but the most generally accepted figures are these, as endorsed by Amnesty International, BMA and others.

2: ‘Bhopal Disaster: Still Waiting For The Clean Up’.  Joe Jackson.

3: Ibid.

4: For comparison of data from all reports referenced in this chapter please see: ‘Analysis of Chemical Contaminants in Groundwater and Assessment of the Qualitative and Quantitative Drinking Water Supply Situation in the Communities Surrounding Union Carbide India Ltd. (UCIL) Plant Site in Bhopal.’ Aio Häberli and Colin Toogood. http://water.bhopal.org/

5: Ibid. For further details of water supply situation to affected communities.

6: Ibid.

7: For data see: ‘Contamination of soil and water inside and outside the Union Carbide India Limited, Bhopal’. Centre For Science and Environment, December 2009.

8: Ibid.

9: Suketu Mehta. New York Times, December 02, 2009.

10: ‘Riding The Elephant’ Blog John Elliott, Dec 1 2009 http://ridingtheelephant.wordpress.com/

11: Hindu, Feb 7, 2010.


  • Aio Häberli and Colin Toogood. ‘Analysis of Chemical Contaminants in Groundwater and Assessment of the Qualitative and Quantitative Drinking Water Supply Situation in the Communities Surrounding Union Carbide India Ltd. (UCIL) Plant Site in Bhopal.’ The Bhopal Medical Appeal, for the Sambhavna Trust Clinic, Bhopal.
  • Dr. Sapna Johnson, Mr. Ramakant Sahu, Dr. Nimisha Jadon, Ms Clara Duca. ‘Contamination of soil and water inside and outside the Union Carbide India Limited, Bhopal’. Centre For Science and Environment, December 2009.
  • Labunska, I., Stephenson, A., Brigden, K., Stringer, R., Santillo, D. & Johnston, P.A. 1999. ‘The Bhopal Legacy: Toxic contaminants at the former Union Carbide factory site, Bhopal, India: 15 years after the Bhopal accident.’ Greenpeace Research Laboratories, Department of Biological Sciences, University of Exeter, Exeter UK.
  • Labunska, I & Santillo, D. 2004. ‘High levels of chlorinated organic compounds, including tetrachloromethane, in water from well adjacent to former Union Carbide India Ltd (UCIL) pesticide plant, Bhopal (India).’ Greenpeace Research Laboratories.
  • National Environmental Engineering Research Institute (NEERI). 1990. ‘Assessment of pollution damage due to Solar Evaporation Ponds at UCIL, Bhopal.’ Published by NEERI, Nagpur – 440 020, Madhya Pradesh Pradushan Nirawan Mandal, Bhopal.
  • Srishti. 2002. Toxic Present – ‘Toxic Future: A Report on Human and Environmental Chemical Contamination around the Bhopal disaster site.’ H-2, Jangpura Extension, New Delhi – 110 014.
  • Stringer, R., Labunska, I., Brigden, K. & Santillo, D. 2002. ‘Chemical Stockpiles at Union Carbide India Limited in Bhopal: an investigation.’ Greenpeace Research Laboratories.
  • Jackson, Joe. ‘Bhopal Disaster: Still Waiting For The Clean Up’. ENDS Report 406, November 2008, pp 32-35


Bhopal – 25 years and exposure continues 

A plan to open the site of the Bhopal disaster for 15 days was labeled a ‘dangerous publicity stunt’ by the gas tragedy survivors, who saw this as an attempt to overshadow their campaign for justice on the 25th anniversary of the disaster.

The two reports by the BMA and CSE, released on 1 December 2009, helped to counteract this bizarre proposal of Madhya Pradesh Minister Babulal Gaur. Gaur, the Bhopal Gas Tragedy Relief and Rehabilitation Minister, announced that the ‘The plant is being opened to help people get rid of the apprehension and misconception that the chemical wastes lying in the factory are still harmful and are polluting the ground water of the nearby localities.’

Gaur based his conclusion that the chemical wastes on site are not harmful on a 2008 report by the Defence Research and Development Establishment (DRDE)1, Ministry of Defence, Gwalior. DRDE tested the acute oral toxicity of samples from unspecified locations within the factory site. These consisted of: excavated waste, lime sludge, naphthol tar, reactor residue, semi-processed pesticide and Sevin tar. DRDE concluded the residues had ‘very low mammalian toxicity’ and that a human would have to eat as much as 200g of the waste to die from it.

The problem in Bhopal is not one of acute toxicity which is unlikely to occur2. As explained in this article, the problem is one of chronic toxicity whereby gradual exposure to these chemicals, especially from contaminated drinking water, is linked to disease, birth defects and cancers. So it is not the LD50 (dose which will kill half of the animals which consume it) that needs to be measured but the acceptable daily intake (ADI). When measuring ADI these pesticides have high chronic toxicity3 – in fact, we should not be exposed to them at all.


1. DRDE Report. Acute Oral Toxicity of Samples of Stored Toxic Wastes at the Former UCIL Plant Site at Bhopal in rats. October, 2008. http://www.indiaenvironmentportal.org.in/files/DRDEOctober2008.pdf

2. The exception to this being the numerous children, in affected communities, suffering from Pica, a condition characterized by an appetite for substances largely non-nutritive, such as clay, chalk, dirt, or sand. There are different variations of pica which  can be from a cultural tradition, acquired taste or a neurological mechanism such as an iron deficiency, or chemical imbalance.

3. The ADI of carbaryl (Sevin) is 0-0.003 mg/kg body weight. The ADI for lindane is 0-008 mg/kg. ADI for aldicarb (temik) is 0-005 mg/kg body weight.


Other Reports:

We believe Dow must finally accept responsibility for Bhopal. Until then, The Bhopal Medical Appeal funds two award-winning clinics in the city. Both offer free, first-class care to victims of the gas disaster or the ongoing water contamination. The survivors have nowhere else left to turn – please help if you can.