In 2009, at the 25th anniversary of the tragedy, the BBC took a sample of water from a hand pump in constant use just north of the plant and had it tested in the UK. It contained nearly 1000 times the World Health Organisation's recommended maximum amount of carbon tetrachloride - a substance suspected of causing cancer and liver damage. Campaigners say Bhopal has an unusually high incidence of children with birth defects and growth deficiency, as well as cancers, diabetes and other chronic illnesses - not just in survivors but among generations born subsequently, according to the BBC.
The accident happened after a leakage of methyl isocyanate (MIC) gas and other chemicals from the plant resulted in the exposure of hundreds of thousands of people in nearby Bhopal. It is a state capital and home to about 900,000 people in central India, many living in closely packed slums. The gas cloud was heavier than air so kept close to the ground, hitting children as well as adults.
You can tell monitoring what happened is not an exact science by the fact that there is so much dispute about the number of deaths. The official immediate death toll was 2259 and the state government of Madhya Pradesh confirmed a total of 3787 deaths related to the gas release. Others estimate 3000 died within weeks and another 8000 have since died from gas-related diseases, leading to the generally accepted figure of 15,000 - although other estimates claim 25,000 deaths. A government statement in 2006 attributed 558,000 injuries, including about 4000 severely and permanently disabling injuries.
To be fair to Union Carbide, they did not just let matters halt at the US$470m compensation. Some estimates claim that payment only worked out to be US$550 per head for those affected - nowhere near the health costs involved in 27 years of aftermath. But the company put US$2 million into the Indian Prime Minister's immediate disaster relief fund on December 11, 1984; established the Employees' Bhopal Relief Fund in February 1985, which raised more than US$5 million for immediate relief; paid an additional US$4.6 million in humanitarian relief; built a local hospital, opened in 2001, from a fund with about US$90 million. The hospital treats heart, lung and eye problems.They also donated US$5 million to the Indian Red Cross.
The head of the organising committee of the London Olympics, Lord Sebastian Coe, has said they will not expel Dow as a sponsor. Protesters have burned effigies of Coe, an Olympic legend with four medals (including two iconic 1500m golds), who has said: "Dow's links with Union Carbide came 17 years after the Bhopal gas leak and it could not be held responsible; nor was it the operator or owner when the final settlement was agreed in 1989. Dow became the major shareholders in that company only in 2001, and the final settlement was upheld on two separate occasions by the Indian Supreme Court. I feel comfortable after analysing the history of this case."
Comfortable? The unanswered and possibly unanswerable question is how many deaths and disabilities have been caused since Bhopal, since Dow owned the company, and whether Bhopal campaigners can link deaths and illnesses to the plant and aftermath - not easy to prove.
But comfortable, Lord Seb? The five Olympic rings are said to represent all countries in the world, linking them together with the Olympic ideals and the Corinthian spirit. There has been a large dent in Olympic ideals with stories of corruption and malpractice over the years but the Olympics are still supposed to be a sporting carnival - not a cash-thirsty commercial stage for companies with damaged images to repair said images. So what if the main Olympic stadium doesn't have the Dow wrap? Who cares?
Already the London Olympics have earned a reputation as the Greedy Games. The announcement of an extra 41 million in government funds to double the cost of the opening and closing ceremonies must cause an even nastier taste in Bhopal mouths. The total cost of the London Olympics has grown from an original 2.4 billion to 10 billion. Some think that figure will rise even further.
It's hard not to think that some of this largesse - even the 1.5m being paid by Dow for the privilege of producing a giant curtain thing - could usefully be donated to the sick and families of the dead in Bhopal.
Without at least such a gesture - and getting rid of Dow would be even better - London is doing itself no favours at all. How anyone can be comfortable with anyone linked with Bhopal, no matter how tenuously, is beyond me.