India, Feb. 12 -- The air quality in the Capital slipped back into the "very poor" category after a gap of six days on Wednesday as low wind speeds, influenced by an approaching western disturbance, reduced the dispersion of pollutants.

The Capital's 24-hour average air quality index (AQI) stood at 305 at 4pm on Wednesday, according to the Central Pollution Control Board's (CPCB) daily bulletin. The AQI had been 271 (poor) at 4 pm on Tuesday, 249 (poor) on Monday and 189 (moderate) on Sunday, indicating a steady deterioration over the past few days. The last time it was in "very poor" was on February 4, when the AQI was 351.

The India Meteorological Department (IMD) said that three western disturbances are set to affect northwest India ...