Delhi’s air was severe on Monday.
The AQI was recorded at 483.
Many stations were above 400.
Other sources gave different numbers.
Pollution curbs were already in place.
The Hans India also reports a reading of 776 for Delhi from AQI.in at 6:51 am on Monday, which comes from a private platform and not from the CPCB.
Organiser reports that Swiss-based IQAir recorded readings above 1,000 in Shahdara and Defence Colony, without giving times or exact values, and says the difference reflects variations in methodologies.
The Air Quality Index runs from 0 to 500, with 0 to 50 good, 51 to 100 satisfactory, 101 to 200 moderate, 201 to 300 poor, 301 to 400 very poor and 401 to 500 severe, according to Organiser.
Readings above 500 are shown as 500 or 500 plus on the official scale, which is one reason private platforms can show higher numbers.
The Graded Response Action Plan Stage III was put in place across Delhi-NCR on November 6, according to Organiser, three days before the Diwali period it describes.
Stage III measures include a halt to non-essential construction and demolition, extra vehicle restrictions and hybrid classes up to primary school level, according to Organiser.
Daily Jagran says Stage IV may be imposed if Delhi’s AQI crosses 450, while its own text refers both to Stage III as implemented and as potential, so the status described in that report is unclear.
In Mumbai, station readings reported by Organiser were 264 at Kherwadi-Bandra East, 226 at Sewri and 221 at Ghatkopar, which fall in the poor range, while the Hans India city table lists Mumbai at 171.
The CPCB city table lists Ghaziabad at 363, Noida at 340, Faridabad at 342, Gurugram at 328, Varanasi at 306, Lucknow at 250, Pune at 242, Ahmedabad at 231, Jaipur at 223, Chennai at 211, Kolkata at 164 and Hyderabad at 122.
Smog over the Indus-Ganga Plain, NOAA satellite image of 2017 (file image), Wikimedia Commons, public domain
