The air quality in Delhi improved to the “very poor” category on Wednesday as pollutants were able to disperse due to slightly better wind conditions, PTI reported. The air quality index in the city was 373 at 6 pm on Wednesday, after remaining in the “severe” category since Sunday. An index value higher than 400 is categorised “severe”.

The air quality in nearby Ghaziabad was “severe” in the afternoon but improved to “very poor” by the evening. The air quality was “very poor” in other cities in the National Capital Region too.

Pollution levels in Delhi are likely to improve as wind speed and ventilation index are marginally favourable for dispersion of pollutants, the Indian Institute of Tropical Meteorology has said. The ventilation index is the speed at which pollutants can get dispersed.

On Tuesday, Chief Minister Arvind Kejriwal had said his government will implement the odd-even rationing scheme for private vehicles whenever required in order to combat the deteriorating air quality. The Supreme Court-appointed Environmental Pollution (Prevention and Control) Authority had on Monday banned construction work across the city and the National Capital Region, as well as industrial activity in heavily polluted areas till Wednesday.

The air quality index of 450 on Sunday was the second worst this year.