CHENNAI: The pollution levels associated with the customary Bhogi bonfire celebrations remained in check on Wednesday, when compared to previous years, largely due to clear skies which helped in faster dispersion of air pollutants.
Chennai recorded an Air Quality Index (AQI) of 121. As per the National Air Monitoring Programme, AQI between 101-200 is categorised as "moderately polluted" and may cause breathing discomfort to people with lung disease such as asthma, and discomfort to people with heart disease, children and older adults. Till 6 am, AQI was around 84 but as the vehicular movement started and industries began operating, the levels gradually increased by noon.
Chennaites woke up to smog-like conditions, but after sunrise the situation eased substantially. Senior Tamil Nadu Pollution Control Board (TNPCB) officials told The New Indian Express that this year the climatic conditions were favourable for faster dispersion of pollutants. Besides, the Bhogi bonfire celebration itself was subdued due to dedicated teams patrolling hotspots and thwarting the burning of rubber and plastics.
"Last Bhogi, chilly weather was prevailing in Chennai with the temperature dropping below normal by 2.5 degrees and there was no wind which pushed the AQI levels closer to the 200 mark. But this year, the sun is bright and shining which is why the smog disappeared by 8 am. We were told that only a few early flights got delayed," the official said.
The official data shows that of the eight Continuous Ambient Air Quality Monitoring Stations (CAAQMS), Alandur has recorded the highest pollution levels with AQI clocking 159 and Particulate Matter (PM 2.5) peaking at 383 ug/m3 (micrograms per cubic meter) as against the permissible 60 ug/m3. Kodungaiyur has recorded AQI of 141, Perungudi 133, Manali 111, Royapuram 98, and Velachery 92, while data for Arumbakkam was not available.
Meanwhile, Shweta Narayanan of Healthy Energy Initiative has refused to come to the conclusion that Chennai had a clear Bhogi compared to previous years.
"Our pollution monitors in North Chennai are popping massive numbers. For instance, our monitor in Arunodaya School in Royapuram has registered PM 2.5 of 834 at around 6 am and the TNPCB monitor in the same locality was not catching one-third of the pollution. Firstly, Chennai does not have enough monitors to assess the actual pollution levels. Secondly, the locations of the existing monitors have to be reviewed and calibrated. Thirdly, there is an urgent need for localised monitoring," she said.
Experts say the power plants in North Chennai are the major source of pollution. Almost all coal fired power plant operators in India have missed the deadline for compliance with the NOx and SOx limits.