Delhi’s average Air Quality Index (AQI), a score of how polluted the air is, was 376 on Diwali, Sunday 8 November, in the “very poor” category, up from 369 on Saturday. On the Central Pollution Control Board (CPCB) scale, 301 to 400 is “very poor” and 401 to 500 is “severe”. At 7 pm, of 59 CPCB stations reporting, 19 were in the “severe” range, 33 “very poor” and 7 “poor”; the worst reading was 460 at Jahangirpuri.
PM2.5, particles small enough to enter the lungs, was the main pollutant, with firecrackers adding to it. Low wind speeds and poor ventilation trapped the smoke. The Decision Support System estimated transport at 19% of the pollution load and stubble burning at 3.5% on Sunday. The Early Warning System expects “severe” air from Monday 9 November for several days.
On Friday 6 November the Commission for Air Quality Management (CAQM) invoked Stage III of the Graded Response Action Plan (GRAP) across Delhi-NCR, on top of Stages I and II. Measures include barring BS-III petrol and BS-IV diesel four-wheelers, suspending non-essential dust-causing construction, hybrid classes up to Class 5, and possibly 50% office capacity.
The Supreme Court heard its own case on air pollution the same day. Chief Justice Surya Kant said the AQI was already close to 400 and called vehicle emissions a major contributor, and said controlling pollution needs a “people’s movement”. Amicus curiae Aparajita Singh said stubble burning accounts for about 14% of pollution. The court asked authorities for immediate, medium-term and long-term plans, including steps to ease traffic congestion linked to inadequate public transport, and listed the case for 16 November.
The hearing also touched on daily life. The bench noted “bumper-to-bumper” traffic on roads linking Delhi to Gurugram, Faridabad, Ghaziabad and Greater Noida, and said farmers should be educated about stubble burning because they would stop once they understood the economic costs. It said Diwali gives poorer people a chance to earn a living but that pollution concerns must also be addressed, and that on closing school classes it would follow expert opinion. Delhi Environment Minister Manjinder Singh Sirsa blamed the AAP-led Punjab government for rising stubble burning, while the CPCB readings that morning were 391 overall, with 30 of 59 stations in the “severe” band and Rohini worst at 475.
On Diwali morning, 24 of 54 stations were already “severe”, among them Punjabi Bagh at 449, RK Puram at 448, Bawana at 446, IIT Delhi at 445 and Rohini at 445. India Gate read 398, Akshardham Temple 336 and Anand Vihar 328, so even the “better” stations were in the very poor band.
The Air Quality Index tells us how dirty the air is. In Delhi it was 376 on Diwali, which is called very poor. Above 400 is called severe, and that is expected from Monday.
Firecrackers and smoke added to the problem. New rules are in force. Dusty building work has stopped, and schools up to Class 5 use hybrid classes. The Supreme Court will hear the case again on 16 November.