Delhi's air quality suddenly improves but AQI still close to 'severe'

The overall air quality index (AQI) on Monday was registered in the severe category at 397 against 434 a day earlier

With Diwali just a day away, Delhi's air plummeted to "hazardous levels" but bounced back to "very poor" category on Tuesday, leaving people gasping for fresh air. 

Meanwhile, air purifiers have been installed at the ITO crossing in Delhi in view of rising pollution levels.

As a thick blanket of haze engulfed the national capital on Monday, experts warned that the air quality is likely to worsen further due to local factors during the festival while doctors said the impact of air pollution on public health can be compared to smoking 15-20 cigarettes a day.

The overall air quality