India, Dec. 13 -- In view of the deteriorating air quality and the prevailing pollution trend, the Commission for Air Quality Management's (CAQM) Sub-Committee on the Graded Response Action Plan (GRAP) has decided to enforce all measures under Stage IV of the plan with immediate effect across the entire National Capital Region (NCR).

Stage IV of GRAP, which is categorised as 'Severe+' air quality, is triggered when the Air Quality Index (AQI) in Delhi crosses the 450 mark.

The Air Quality Index (AQI) was recorded at 448 at 7 pm on Saturday, according to data from the Central Pollution Control Board (CPCB). The 24-hour average AQI was recorded at 349 (very poor) at 4 pm a day earlier.

Forecasts by the Air Quality Early Warning System fo...