Many parts of the city, including Ennore, Perungudi, Arumbakkam, Royapuram, and Manali, had poor air quality on Sunday as residents celebrated Bhogi by burning waste. The smoke combined with the fog to form smog.
According to data from the Central Pollution Control Board’s (CPCB) Sameer mobile app, the air quality index (AQI) at Perungudi was 251 at 3.01 a.m. with the major pollutant being particulate matter 2.5 (PM2.5). The ground ozone was 54 at that time. With no winds to disperse the pollutants, the AQI was 328 at 7.05 p.m. on Sunday. The levels of both major pollutants PM2.5 and particulate matter 10 (PM10) reached 500 and 455 respectively.
The city’s AQI, which was 135 at 4 p.m. on Saturday, rose to 183 at 3.05 a.m. on Sunday. This then became 200 at 8.22 a.m., 212 at 10.15 a.m., and 228 at 7.05 p.m. Gummidipoondi recorded an AQI of 302 at 7.05 p.m., PM2.5 being the major pollutant, while Chengalpattu recorded an AQI of 239.
