The Chennai Solidarity Group, an alliance of city based NGOs has released a report countering RTI information recently reported about the air quality in Thoothukudi district, after Sterlite Copper's closure. On December 5, ToI published a story that the air quality in the city has remained the same since the copper smelter was shut down on May 28, 2018.
The article, based on information obtained from the Tamil Nadu Pollution Control Board (TNPCB) stated that while the readings for NOX or nitrogen oxides remained the same between 2017-18 and 2018-19, the SO2 or Sulphur dioxide levels in the air changed from 13 micrograms per cubic metre to 12 micrograms per cubic metre in the same period. And while the story mentioned that the readings were from a pollution monitoring station at the Fisheries College in Thoothukudi, it did not specify who filed the RTI. Moreover it cited only two pollution parameters (SO2 and NOX) to arrive at the conclusion).
A more detailed analysis done by the Chennai Solidarity group meanwhile takes into account the changes in the Air Quality Index (AQI) between April 2017 to March 2018 and April 2018 and March 2019. Data from three stations that come under the Central Pollution Control Board's National Air Monitoring Programme have been analysed. This includes Raja Agencies, SIPCOT and AVM monitoring stations.
The data taken from TNPCB's website shows that the number of days with unhealthy air quality recorded in the SIPCOT industrial complex where Sterlite is located has reduced by half in comparison to before. Between April 2017 and March 2018, when the factory was in operation, air quality was unhealthy for more than 56% of the time. Between April 2018 and March 2019, it had reduced to 27 %. The number of days with acceptable air quality too increased from 44% to 73%.
At Raja agencies too, the number of days with acceptable air quality increased from 5% to 42 % after Sterlite's closure. In AVM meanwhile, the number of days where AQI was recorded as satisfactory, was 64 compared to 40 between 2017-18.
Measuring AQI is considered to be one of the most reliable methods to study air pollution across the world. It involves considering eight pollutants - PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb to understand the quality of the air.
Sources in the TNPCB meanwhile point out that if the SO2 and NOX levels are unchanged in a single monitoring station, it does indicate that there has been no change in air quality.
But Sterlite in an email in response to TNM's questions on the subject said, "To ascertain if the industry is really causing an impact on the ambient air quality or not, it is only the emissions that are usually associated with the plant operations that should be considered to understand the impact if any, if it could have caused. Therefore, only NoX & SO2 emissions may have been considered in demonstrating the impact on air quality by the said industry."
TNPCB however argues that the data offered is insufficient.
"This data is very selective. To actually understand this, we need to constitute a study with experts and multiple samples. You cannot take a single reading and come to this conclusion. The overall air quality would have definitely improved," says the official.
Moreover, the TNPCB source states that air pollution was not the primary reason for shutting down of the smelter. Amongst the reasons offered to court were - the dumping of copper slag, groundwater pollution, improper disposal of hazardous waste and failure to conduct studies on arsenic content.
"Why are they comparing air quality now? Can they show change in what we have shown in court? Have they cleared the copper slag dumped in Uppar river?" asks the official. "Air pollution came up because of a 2013 leak in the smelter. But in 2019 we haven't discussed about air pollution at all. Someone is trying to change the narrative."
When TNM asked Sterlite about the need to bring about a discussion on air quality, the management agreed that it was not a cause for the closure.
"Air pollution was not among the grounds cited for either the rejection of Consent to Operate or the subsequent plant closure. However both prior and post the closure, allegations were levelled that the company’s operations were responsible for emitting high levels of SO2, and this misinformation became a subject matter of discussion in various forums," the company said in response to an email. "However, it is important to note that when the plant was functional, the SO2 levels have consistently remained under the GOOD category of the AQI, which is something we have consistently reiterated."