The Tamil Nadu Pollution Control Board's report on the improved air quality in Thoothukudi following the shut down of the Sterlite Copper plant, was contested by the company at a final hearing on Monday. Sterite's counsel, while addressing the media in Chennai, disputed the methodology adopted by the TNPCB to arrive at the conclusion. TNPCB's data directly contradicts Sterlite's earlier claim that the shut down of their plant had made no difference to air quality in the region.
On Sunday, Sterlite told the National Green Tribunal appointed expert committee that RTI data accessed between the months of October 2017 and July 2018, show that there has been no significant change in the air quality following the shut down of the plant. The plant was shutdown in March 2018. According to the documents, SO2 levels were 13.62 micrograms per cubic metre in October 2017 and in July it was recorded to be 13.61 micrograms per cubic metre. Figures in May show that SO2 levels actually rose up to 15.04 micrograms.
But data provided by the Tamil Nadu Pollution Control Board shows that levels of NO2 and SO2 have seen reduction following the shut down of the plant. Nitrogen dioxide (NO2) and sulphur dioxide (SO2) are known lung irritants and can cause respiratory problems. NO2 however is caused by most processes of combustion including vehicular movement. The smelting process also results in particulate matter. This is a complex mixture of extremely small particles and liquid droplets that get into the air. When inhaled above permissible limits, these particles can affect the heart and lungs and cause serious health effects.
Talking to TNM, Abdul Salim, the counsel for the TNPCB pointed out that, "From 20 micrograms per cubic metre in September 2017, the levels of SO2 has come down to less than 5 micrograms this months . Similarly NO2 levels have come down from 15 micrograms per cubic metre to less than 7 micrograms per cubic metre. This is a substantial difference and the ambient quality has definitely improved."
The study conducted however only gives the average of the pollutant levels taken over a single day in September and two days in October. When this was pointed out, the lawyer says more evidence of 'violations' have been submitted to the NGT committee.
"There are two three instances where the permissible limits of pollutants have been violated. The particulate matter meanwhile, is increasing because of vehicular movement and because of dispersion of slag on the premises."
But Associate Vice President of Sterlite Copper A Sumathi, points out that the data recorded and submitted by TNCPB has only considered levels of gaseous by products for a day or two. She argues that the data should have been taken over a period of time and a trend established.
"The PCB has not submitted long term data. And even if the data submitted is correct, permissible limits for SO2 and NO2 is 80 micrograms per cubic metre. So both the numbers they have provided fall under that limits," she argues. "Moreover the lab that has conducted the tests, is an external facility. They have not followed the rules prescribed in the The Air (Prevention and Control of Pollution) Act, 1981 and The Water (Prevention and control of pollution) Act of 1974 ," she alleges.
Sources in the TNPCB however dismiss Sterlite's claim. Under the condition of anonymity, an official said, "We are not arguing about permissible levels at all. We are merely dismissing Sterlite's submission that there is no change in air quality. We have used a highly reputed lab to conduct the tests. We have submitted the data in the appropriate forum. We have not manipulated any information that has been presented."
Meanwhile, the three member committee has finished the hearing in the case on Monday and is likely to submit its report by the end of November. The NGT's principal bench will be hearing the case on December 10.