Centre's air quality panel revokes Grap-4 curbs as pollution levels dip

The Centre's panel on Delhi-NCR's air quality on Thursday revoked curbs under stage 4 of the Graded Response Action Plan (GRAP) amid dip in pollution levels, according to an official order.

The curbs were imposed Wednesday as calm winds, low temperatures and foggy conditions allowed accumulation of pollutants in the region, with the air quality index clocking 396 last evening.

Stage 4 curbs include a ban on all construction activities, entry of non-essential polluting trucks into Delhi, and mandatory shifting of school classes, except for classes 10 and 12, to hybrid mode.

Non-essential diesel trucks are prohibited from entering Delhi, while Delhi-registered BS-IV and older diesel-run heavy goods vehicles are banned, except for essential services under Stage 4.

During winters, the Delhi-NCR region enforces restrictions under GRAP, which categorizes air quality into four stages Stage 1 (Poor, AQI 201-300), Stage 2 (Very Poor, AQI 301-400), Stage 3 (Severe, AQI 401-450), and Stage 4 (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.