BENGALURU: An analysis of winter air pollution holds good news for Bengaluru: the city has been able to hold on to most of the air quality gains made during the lockdown in 2020. The analysis, as per Air Quality Index (AQI) categorisation, indicated that in South India, Chennai and Kochi have shown a similar trend. The Centre for Science and Environment (CSE), New Delhi, released the analysis on Friday.
For Bengaluru, the number of 'good' AQI days in 2021 stood at 208 -- just marginally lower than the 214 days recorded in 2020. Interestingly, within the city, Bapuji Nagar, mostly a residential zone, was the worst-hit with its December average recording 76 ug/m3. Peenya, despite being the industrial hub, had the least polluted air with a 36 ug/m3 monthly average for December 2021.
Avikal Somvanshi, programme manager, Urban Data Analytics Lab at CSE, observed that the cause of emission due to vehicular traffic and garbage burning domestically in areas like Bapuji Nagar, contributed to air pollution, whereas better regulation and monitoring in Peenya helped check pollution. "In fact, the AQI is worse in BTM Layout and Jayanagar than in industrial hubs," he remarked.
The analysis covers ten continuous ambient air quality monitoring stations (CAAQMS) in Bengaluru, of which data was not available for the second half of 2021 (June to December) from two stations -- City Railway Station and Sanegurava Halli.
In Karnataka, one station each in Bagalkot, Bidar, Chamarajanagar, Chikkaballapur, Chikkamagaluru, Davanagere, Gadag, Hassan, Hubballi, Kalaburagi, Kolar, Koppal, Madikeri, Mangaluru, Mysuru, Raichur, Ramanagara, Shivamogga, Udupi, Vijayapura and Yadgir have also been covered.
Gadag and Kalaburagi reported bad air days, in fact, the AQI in these cities can cross into 'very poor' category, but due to the massive amount of missing data, it is unclear how long these bad air episodes actually last, the report clarified.
During the worst weekly pollution episode in winter, Gadag registered a weekly average of 192 ug/m3 (almost five times its annual average) and Kalaburagi clocked 104 in mid-December. As for the seasonal increase in NO2 concens, Kalaburagi registered a 5.8 times jump in monthly NO2 levels, Hubballi was 3.3 times more compared to the months of November, October and September.
There is a significant increase in the amount of surface ozone (O3) in the air as Kalaburagi (93 µg/m3) and Udupi (81 µg/m3), figured in the report. "There is a need for urgent action across all sectors to control pollution from vehicles, industry, power plants, waste burning, construction, and solid fuel use in households in all the states to meet clean air standards throughout the year," said Anumita Roychowdhury, executive director, research and advocacy, CSE.