The air quality in Delhi has slipped into the “very poor” category as of today, Monday, November 10, with the Central Pollution Control Board (CPCB) recording an Air Quality Index (AQI) of 391.

Despite this breach of the 350 mark, which has been cited in the past as the threshold for triggering Stage 3 of the Graded Response Action Plan (GRAP), the Commission for Air Quality Management (CAQM) has not yet moved to Stage 3, India Today reports.

Under the current system, GRAP Stage 1 is invoked when AQI is between 201-300, Stage 2 for 301-400, Stage 3 for 401-450, and Stage 4 for anything above 450. 

While Stage 2 restrictions, including banning certain construction operations, rationing parking, and curbing private vehicle use, are in effect, Stage 3 would introduce significantly stricter measures. 

These would include a full ban on older-emission-standard vehicles, cessation of non-essential construction and demolition, and implementing work-from-home or online classes wherever possible.

In many regions, the air has become so poisonous that health officials are warning residents about potential respiratory risks.

According to environmental research, breathing the air in Delhi is now akin to smoking several cigarettes every day. 

People living in locations with a 'very poor' AQI inhale air that is as dangerous as smoking 6 to 10 cigarettes per day, but those in 'severe' zones are effectively exposed to the equivalent of 16 to 20 cigarettes.

In reaction to the deteriorating air quality, numerous Delhi schools discontinued outside activities.

Morning assemblies, physical education classes, and playground sessions have all been relocated indoors to ensure children's safety. Many schools have also installed air filters in their classrooms and auditoriums.