Housewife A. Puneeta was washing dishes on a foggy Saturday morning when suddenly her throat began to burn. Coughing hard and struggling to breathe, she rushed into the street to find her neighbours running, haphazardly, in panic.
"First people said there was a gas leak, and then someone said Sterlite seemed to have opened up something, and that's the cause of the throat burning," said Puneeta, 32, who is married to a fisherman in this port town near the southern tip of India.
She was referring to Sterlite Industries, a unit of London-based Vedanta Resources, which operates India's biggest copper smelter a few miles (kilometres) away, and which has been shut by authorities despite the firm denying the smelter was to blame for the emissions in the area on March 23.
Other residents recounted similar stories. Two spoken to separately by Reuters also said the emissions caused leaves on plants and trees to wither and drop in front of their eyes, while another, who is asthmatic, said she struggled to breath as she walked home from church and had to use her Ventolin inhaler.
The plant employs 4,000 and supports thousands more jobs indirectly. But since opening in 1996 it has split this coastal city between residents who say it is crucial for the local economy and farmers and fishermen who see it as a health hazard.
Similar debates are playing out across India where disputes over safety, the environment and livelihoods overshadow the efforts of Asia's third-largest economy to industrialize. Just 100 km (62 miles) south, in Kudankulam, fishermen are fiercely opposing a new nuclear power plant.
Tuticorin and Kudankulam sit on the Gulf of Munnar, famed for its pearls, coral reefs, and marine life. Environmental activists who say Sterlite is damaging the region's ecology have been fighting for years to close the smelter permanently.
The state of Tamil Nadu's Pollution Control Board closed the smelter until further notice late last month and said a sensor in the smelter's smokestack showed sulphur dioxide levels were more than double the permitted concentration at the time emissions were reported.
Sterlite denied the smelter, which makes half the copper India produces every year, was the source. The smelter's general manager of projects said there were no emissions at the time because the plant was starting up after two days of maintenance, not producing copper, and high readings in the smokestack were likely a result of workers recalibrating the sensors.
On Tuesday, a fast-track environmental court will hear a petition to allow it to reopen, a move being closely watched by environmentalists and the global copper market.
HISTORY OF ENVIRONMENTAL POLLUTION
Anti-smelter activist P.A. Dharmaraj does not see eye-to-eye with his neighbour, who is a supporter of the plant. The former farmer says pollution from the smelter two km (1.4 miles) from his house had poisoned crops, driving him out of business.
"As soon as sulphur dioxide started being emitted by the Sterlite plant, the rainfall naturally decreased," he said. "Rain ... will not fall on our lands since then. Our crops also started getting scorched because of the emissions."
Sulphur dioxide emissions can cause acid rain, although the impact on weather patterns is more complex, scientists say. U.S. advocacy group the Environmental Law Alliance Worldwide in 2010 said a soil sample taken from outside Dharmaraj's house contained arsenic levels ten times that considered safe in Britain, as well as high quantities of toxins such as cadmium.
In the courtyard of Dharmaraj's house, his neighbour M. Mariammal argued in favour of the plant - where her son, a graduate, works as a supervisor. She does, however, now buy bottled water because of concerns that wells may have been polluted, but said it was a price worth paying.
"I wouldn't have money to buy either water or rice if my son didn't have that job," she said.
Sterlite has a history of environmental pollution after a 2005 government study said the smelter leaked arsenic and heavy metals into the soil and water. The company says it has since complied with recommendations by pollution authorities to improve environmental standards.
India's Supreme Court last week fined Sterlite $18.4 million for polluting water, soil, and air around the plant and documented 15 years of abuses. The ruling, part of a long-running case brought by environmental activists, came just days after the suspected gas leak.
The court cited the 2005 government study that found levels of arsenic in ground water near the site were eight times those recommended by the World Health Organisation (WHO). Cadmium, chromium, copper and lead levels also exceeded drinking water standards in some wells.
Despite imposing the fine, the Supreme Court sided with Sterlite and overruled a lower court in Tamil Nadu that had ordered the smelter to shut down. The Supreme Court said the plant was a big source of employment, copper and revenue and the firm had taken steps since last year to stop the pollution.
5,000 ESTIMATED TO BE AFFECTED
A document from Tamil Nadu state's Pollution Control Board obtained by Reuters said Sterlite released two gas plumes early on the morning of March 23, containing as much as 2,941.12 milligrams per cubic metre of sulphur dioxide, almost off the sensor's chart and more than double a government limit for smokestack concentration.
"The recording was about 3,000. The sensor can record only up to 3,000," Tamil Nadu Pollution Control Board Chairman D. Karthikeyan said.
The pollution board does not have an air measuring station in the area of town affected, 5 km (3 miles) downwind from the smelter, but it said reported symptoms suggested levels there could have hit 13,000 micrograms per cubic metre - massively exceeding a national ambient air quality limit of 80 micrograms per cubic metre for sulphur dioxide.
The U.S. Environmental Protection Agency warns against exposure of more than 1,430 micrograms for three hours a year.
Sterlite's general manager of projects, D. Dhanavel, said the high sulphur dioxide readings could have been due to workers adjusting the sensors on the smokestack after the maintenance.
"Whenever we start the factory, we calibrate all the instruments," said Dhanavel. "Now we have to check if it was a calibration error or some other issue."
That explanation did not satisfy pollution authorities. After giving Sterlite five days to explain, the pollution board ordered the plant to close until further notice.
"The reply of the unit is unsatisfactory and untenable," the board said in its order to close the plant, seen by Reuters.
No serious health problems have been reported so far, but the office of Tuticorin's district collector, the town's most senior government official, estimates up to 5,000 people were affected by the emissions.
The future of the plant - which is seeking approval to double its capacity to 800,000 tonnes per year - now hinges on the decision of the National Green Tribunal.
Pollution Control Board lawyer Abdul Saleem said the company would have to appeal again to the Supreme Court if the tribunal rules against it.