Air quality across Delhi slightly improved on Sunday and the overall AQI reached at 297 in ‘poor’ levels, according to data from the System of Air Quality and Weather Forecasting And Research (SAFAR).

However, in the national capital, the Anand Vihar station entered in the ‘very poor' category with PM 2.5 at 305 and PM 10 at 261, in poor category, as per the Central Pollution Control Board (CPCB).

The AQI between zero and 50 is considered 'good'; 51 and 100 'satisfactory'; 101 and 200 'moderate'; 201 and 300 'poor'; 301 and 400 'very poor'; and 401 and 500 'severe'.

The Bawana station recorded PM 2.5 was at 339, very poor category, and PM 10 at 278 (poor) while the CO reached 103 (moderate).

The station at Dwarka sector 8 witnessed a rise in PM 10 levels and it was recorded at 491, in severe category, and PM 2.5 at 379(poor) while CO was at 121.

The air quality at the Indira Gandhi International (IGI) Airport T3 area was in the 'poor' category with PM 2.5 at 300 and PM 10 at 185 in moderate levels.

The PM 2.5 at Okhla Phase-II was recorded at 336, in very poor category while PM 10 reached 260, placing it under the ‘poor’ category. The NO2 plunged to 143 and CO was at 122, both in moderate levels.