In 2022, Delhi saw the lowest number of ‘severe’ air days since at least 2016, according to data from the Central Pollution Control Board (CPCB).
While the city recorded six days in 2022 when the Air Quality Index (AQI) was over 401 or in the ‘severe’ category, there were 24 such days in 2021 and 2019 each, 19 days in 2018, 15 days in 2020, nine ‘severe’ air days in 2017 and 25 such days in 2016.
In terms of the number of days when the AQI was in the ‘very poor’ category (from 301 to 400), Delhi recorded 65 such days in 2022 till December 30, more than 63 days in 2021 and 48 such days in 2020.
On Sunday, the AQI was 259, in the ‘poor’ category, in Delhi. The air quality is likely to deteriorate and remain in the ‘very poor’ category from Monday to Wednesday, according to a forecast issued by the Air Quality Early Warning System for Delhi. At 10 am on Monday, the 24-hour average AQI in Delhi was 317, in the ‘very poor’ category, with most monitoring stations recording air quality in the ‘poor’ or ‘very poor’ categories, CPCB data shows.
The average PM2.5 level in Delhi in 2022 till December 29 was a little below 100 µg/m3. This is only the second year since 2016 – the first being in 2020 – when the annual average PM2.5 level in the national Capital has remained below 100 µg/m3. According to the National Ambient Air Quality Standards, the annual standard for PM2.5 levels is 40 µg/m3.
A host of factors have been associated with relatively better air quality in the winter of 2022 – a warmer start to the winter, better wind speeds that have contributed to the dispersion of pollutants, lower contribution of stubble burning to PM2.5 levels in Delhi, and Diwali being celebrated in October this year when warmer conditions prevailed.