Audio Transcript:

The 1984 gas leak in Bhopal India destroyed the lives of more than half a million people. But in the United States, the disaster led to a sea of changes that have made for a safer environment. The World's Multimedia Science Journalist, Rhitu Chatterjee, has the report.

MARCO WERMAN: I'm Marco Werman and this is The World, a co-production of the BBC World Service, PRI and WGBH/Boston. Residents of Bhopal, India, took to the streets today to mark the 25th anniversary of the world's worst industrial disaster. Thousands were killed there on December 3, 1984 when a chemical factory released a cloud of deadly gas. Yesterday, we reported on the toxic legacy of the plant, which still hasn't been fully cleaned up. Today, the World's science correspondent Rhitu Chatterjee reports on Bhopal's unlikely legacy in the U.S.

CINDY BROWN: This is the site. I haven't been here for quite a while.

RHITU CHATTERJEE: Cindy Brown walks up to a low-slung concrete building in the small city of Worcester, Massachusetts. In the 1980s, this was a specialty chemicals factory, and Brown lived just a few blocks away in a dense residential neighborhood.

BROWN: That field that we saw at the end of the building, I remember my brothers playing football back there.

CHATTERJEE: The factory spewed noxious fumes and particulate matter into the air, Brown says. Neighbors grumbled but no one did anything.

BROWN: This is Worcester, a very industrial city. I think many of us were very complacent, didn't think much about what was going on in a plant in our neighborhood.

CHATTERJEE: Then, on December 3, 1984, came news of the catastrophic industrial disaster in Bhopal, India. Thousands dead from a gas leak at a Union Carbide pesticide plant. Hundreds of thousands sickened. The events of that day set off long ticking alarms here in Werster.

BROWN: The Bhopal disaster made us realize how quickly something could turn into a major disaster.

CHATTERJEE: Brown and much of the rest of her neighborhood quickly mobilized, and before long, they had forced the company to relocate to a non-residential area. What happened in Brown's neighborhood in the mid-80s was part of a growing wave that washed across the United States following the Bhopal tragedy.

LEWIS: People began to look at facilities in their neighborhoods in a different way.

CHATTERJEE: Sanford Lewis is an environmental lawyer who helped Cindy Brown's community. He and others say the Bhopal disaster was a sort of tipping point in American awareness of the dangers of industrial chemicals. Memories of similar incidents were fresh in people's minds, including the dumping of toxic waste by the W. R. Grace Company in Woburn, Massachusetts, and by Hooker Chemical in Love Canal, New York. Kenneth Geiser is a toxicologist at the University of Massachusetts, Lowell.

GEISER: So when the news came about the gas release in Bhopal that sort of fit into a general anxiety. You know, "Could this happen in my neighborhood?" "What is that plant doing down the road?"

CHATTERJEE: Within two years, the growing concern led to major new federal legislation. The Emergency Planning and Community Right to Know Act for the first time gave all communities the right to know about potential industrial hazards, and it helped communities to better prepare for possible industrial accidents. Kenneth Geiser says the new law also included what was thought at the time to be a relatively small provision called the Toxics Release Inventory.

GEISER: Which was to require firms that released chemicals to the environment needed to annually report that to the EPA. And it turns out to be enormously more chemicals than anyone had dreamed.

CHATTERJEE: The TRI proved to be a powerful tool for communities, an environmental lawyer Sanford Lewis says it proved valuable for industry as well.

LEWIS: Most companies didn't know how much of these chemicals they were emitting. So when they had to go and figure it out, some companies discovered that they were wasting a lot of product materials. And so, a lot of companies discovered they could save money. So they began to manage the chemicals better.

CHATTERJEE: The risk from industrial chemicals has hardly been eliminated in the U.S. in the 25 years since Bhopal, but it has been generally reduced, and Bhopal was a catalyst for similar changes elsewhere. Europe tightened regulations on the handling and use of industrial chemicals. Labor groups around the world demanded lower risk work environments. And U.N. agencies began pushing for higher awareness and disaster preparedness. Toxicologist Kenneth Geiser.

GEISER: The world that has happened since 1984 is a dramatically different place. You can just count hundreds of things all of which stem in one part or another back to the awareness that came from seeing such a tragic incident.

CHATTERJEE: But what about back in India where the accident actually happened? Bhopal spurred a flurry of new laws and regulations, including India's first Environmental Protection Act. The shock of Bhopal also reverberated in India's legal system. That's according to Shyam Divan, a Senior Advocate of the Indian Supreme Court.

DIVAN: You had a series of judgments of the Supreme Court, which for example, started shutting down factories which were not complying with environmental standards.

CHATTERJEE: Divan says together the legal and regulatory changes following Bhopal had a real impact.

DIVAN: I think at least in so far as the worst type of disasters is concerned this is still sufficient to ensure that those types of tragedies are averted.

CHATTERJEE: But many Indians believe the country isn't much better off in terms of chemical hazards than it was 25 years ago. They say enforcement of the new laws is lax. And that in a crowded and rapidly industrializing country even more people are living close to potentially dangerous industries. Critics also say that unlike in the U.S. little has changed in regard to emergency preparedness and public information. Rabi Agarwal runs an environmental group in New Delhi. He says Indians remain largely in the dark about chemical hazards.

AGARWAL: The lack of public awareness both to put accountability to such processes, but also to cope with such accidents that remains to be very, very poor still.

CHATTERJEE: And Agarwal says until existing laws are enforced and the public is truly aware of the hazards in their back yards, India may remain at risk of many smaller Bhopals. For The World, I'm Rhitu Chatterjee.