Delhi recorded its first poor air quality day of the season on Wednesday, October 21, with the overall Air Quality Index (AQI) hitting 227 at 7 am, according to Central Pollution Control Board (CPCB) data reported by Daily Jagran. The CPCB classifies AQI between 201 and 300 as 'poor', meaning the air can cause breathing discomfort for most people.

The deterioration came overnight after Dussehra celebrations across the capital on Tuesday evening. Daily Jagran reported that emissions from Durga Puja festivities, Dussehra firecrackers and effigy burnings added to pollution, while the city's AQI had climbed from 90 on Friday to 159 on Saturday and 187 on Sunday, eased to 139 on Monday, and stood at 179 on Tuesday, a figure also reported by Livemint.

The Air Quality Early Warning System had forecast the slide. Livemint reported the air was expected to remain in the poor category until October 23, with the outlook for the following six days also pointing to poor air, while Daily Jagran, citing the forecast, said poor air could last until October 28. Both reports said unfavourable weather — wind speeds likely below 10 kmph and a low ventilation index — would hamper dispersal of pollutants. Nation Press also reported Delhi-NCR air quality turning 'poor' after Dussehra, with levels expected to worsen till October 23.

Stubble burning in neighbouring states was cited as another factor. Daily Jagran, citing a Hindustan Times report of NASA satellite data, said 182 stubble-burning incidents were counted in Punjab and Haryana between October 18 and 20, with 397 farm-fire incidents recorded this month so far, compared with 523 over the same period last season.

Before Wednesday, Delhi last recorded poor air on July 13, when the AQI stood at 246, Daily Jagran said. Sources: Daily Jagran (CPCB data), Livemint, Nation Press.