Delhi-NCR invokes Grap Stage-III curbs amid sharp dip in air quality

The Commission for Air Quality Management on Saturday invoked stricter Grap Stage-III restrictions, including shifting schools to hybrid mode up to Class 5 and restrictions on construction and demolition work, in Delhi-NCR after pollution levels rose sharply amid unfavourable meteorological conditions.

The national capital's 24-hour average air quality index (AQI) stood at 349 but jumped to 401 by 10 am on Saturday, "owing to slow wind speed, stable atmosphere, unfavourable weather parameters and meteorological conditions and lack of dispersal of pollutants", the Commission for Air Quality Management (CAQM) said in a statement.

It said that due to the prevailing trend of air quality, and to further prevent deterioration in the region, the CAQM Grap Sub-Committee on Saturday took the call to invoke all actions under Stage-III of the Graded Response Action Plan (Grap) 'Severe' Air Quality with immediate effect in the NCR.

This is in addition to the actions under Stages I and II of Grap already in force in NCR, the statement added. Stage III restrictions include a ban on non-essential construction, demolition work, stone crushing and mining activities. BS III petrol and BS IV diesel four-wheelers are also restricted in Delhi, Gurugram, Faridabad, Ghaziabad and Gautam Buddh Nagar.

It also entails a ban on older diesel goods vehicles in Delhi, while schools up to Class 5 shift to hybrid mode and offices may operate with 50 per cent staff in Delhi-NCR.

During winters, the Delhi-NCR region enforces restrictions under Grap, which categorises air quality into four stages - Stage I (Poor, AQI 201-300), Stage II (Very Poor, AQI 301-400), Stage III (Severe, AQI 401-450), and Stage IV (Severe Plus, AQI above 450).

Unfavourable meteorological conditions, combined with vehicle emissions, paddy-straw burning, firecrackers and other local pollution sources, lead to hazardous air quality levels in Delhi-NCR during winters.