Pollution studies
An epidemiological study carried out by Tirunelveli Medical College in 2006–07 found an increased prevalence of respiratory diseases and ear, nose and throat (ENT) morbidity in the 5-km radius of Sterlite Industries. The study reported the prevalence of respiratory diseases in the area at 13.9% which was far higher than the state average. The prevalence of asthmatic bronchitis is 2.8%, which more than two-times the state average of 1.29%. Myalgia (general body pain) is another extensively reported symptom and women were often found to have menstrual disorders, like menorrhagiae and dysmenorrhagiae in the area.[26] Their report blamed it on the air pollution caused by the industry's thermal power plants and automobiles in the area.[27] The groundwater iron content in the area of the plant has been found to be 17–20 times the allowable limit, causing additional health problems for the population already experiencing higher than average incidence of respiratory diseases. During the time of this Study at 2007, Sterlite was operating at about 18 to 42 percent, compared to its 4 Lakh Tonnes per Annum in the year 2017–2018.[28][29]
The 1998 report by National Environmental Engineering Research Institute (NEERI), the levels of selenium, arsenic and lead in treated effluent were higher than specified standards. The team also found dead birds after they consumed the water mixed with the effluent and also reported that the industry's process of cooling the effluents can cause health hazards to the staff and residents in the local region. In another instance, the NEERI reported water samples from dugwells and borewells around the spot were found to be non-drinkable due to its high chemical content. During 1998, the industry was operating at 10% capacity, compared to that of 2018.[30][31]
In a 2005 environmental audit by NEERI, the samples from a village 2-km northwest of the factory had levels of cadmium, copper, lead, chromium, and arsenic 2 to 9 times higher than allowed levels. Soil Samples were also analyzed in areas surrounding the plant during the study and arsenic levels ranged from 133 mg/kg to 287 mg/kg, where soils containing more than 50 mg/kg of arsenic are supposed to treated as a 'hazardous wastes' under the Indian Law.[30]
In October 2010, sampling tests by an NGO, Community Environmental Monitoring, found salinity level in an open well to be of 7854 mg/litre while levels exceeding 2000 mg/litre can badly damage the crops. Another water sample from a bore-well had sulfate levels 10 times higher than the average. A soil sample from the same spot contained 335 g/kg of iron and an ingestion of just 3.5 grams by a child can be a serious case of iron poisoning.[30]
A scientific study in 2017, found most of the ground water samples in the area are highly contaminated with heavy metals like arsenic, lead, boron etc. which were higher than the World Health Organization's prescribed limit.[32]
The Tamil Nadu Pollution Control Board (TNPCB) observed that the unit has been releasing poisonous gas in the air. TNPCB identified that the sulphur dioxide levels went off the scale on the night of 23 March 2013. It showed a reading of 2939.55-mg/cubic meter against the decreed limit of 1250 mg/cubic meter.[25][33]
On 9 April 2018, the TNPCB accused the Sterlite Copper of causing groundwater pollution.[34]
Gas leaks
On 6 July 1997, the Tamil Nadu Pollution Control Board told the company to shut down after a sulphur dioxide gas leak which hospitalized more than 90 people.[35]
The Sterlite Copper factory also made headlines in 2013 after a suspected sulphur dioxide gas leak from one of its smelter.[36] The plant was blamed for health issues observed in the area related to gas leakage and residents near-by complained of coughing, wheezing, eye irritation, and miscarriages following the leak.[37] Following the alleged gas leak in March 2013, the then chief minister, the late J. Jayalalithaa, ordered its closure. The company appealed to the National Green Tribunal, which overturned the government order. The state moved the Supreme Court against it, where the petition was still pending. The plant closed on 27 March 2018, with the company citing a 15-day maintenance process.[38] The Supreme Court ordered the company to pay a 100-crore fine for polluting the water, air and soil around the plant and the factory was temporarily shutdown by the pollution regulator.
