No 'severe' AQI cities in India for third consecutive year post-Diwali

Historically, the post-Diwali haze has lingered, especially with winter weather compounding the pollution from firecrackers

For the third consecutive year, on the day after Diwali no major city in India touched the air quality index (AQI) of 401 micrograms (one-thousandth of a milligram) of P2.5 particulate matter per cubic metre, the threshold for “severe” air quality.

  This is in sharp contrast to years earlier. This Diwali’s aftermath was markedly cleaner, with only 12 cities reporting “very poor” (301-400) air quality as against 53 cities last year, according to the Central Pollution Control Board (CPCB), Ministry of Environment, Forests and Climate Change (MoEFCC).

  The CBCB data is based on the average of the past 24 hours. An AQI of 50 or below is considered “good”, while “satisfactory” falls between 51 and 100. A “moderately polluted” reading ranges from 101-200, “poor” extends from 201-300, “very poor” is between 301 and 400, and anything above 400 is deemed “severe”.

 

  Historically, the post-Diwali haze has lingered, especially with the winter weather compounding the pollution from firecrackers. But recent improvements reflect a shift: The years 2020 and 2021 were the most polluted, with AQIs in the “severe” range in 12 cities in 2020 and 22 cities in 2021.

 

  This year Ambala registered the highest AQI at 367 the day after Diwali, while previous years had even starker readings: Begusarai led in 2023 with an AQI of 382, Jodhpur topped 2022 at 337, Noida hit 475 in 2021, and Jind marked 457 in 2020.

  Delhi breathed in relatively good air the day after Diwali, with an AQI of 339. The worst post-Diwali AQI levels in Delhi were recorded in 2021 and 2020, with AQIs of 462 and 435, respectively.

  The Air Quality Early Warning System for Delhi, under the Ministry of Earth Sciences, forecasts the city’s air will hover at the upper end of the “very poor” category from Saturday through Monday. The longer view isn’t much brighter either -- for the next six days, the air quality is expected to stay locked in the same range.

  This slight increase in air pollution likely stems from violations of the ban on bursting firecrackers in Delhi.

 

Compounding the issue are familiar seasonal factors: The onset of winter brings cooler, denser air, which traps pollutants, while road dust, vehicular emission, and stubble burning in neighbouring Punjab and Haryana contribute to Delhi’s annual dip in air quality.

 

  However, external pollution sources like stubble burning are on a sharp decline, easing the strain on air quality across hundreds of cities.

 

According to the Indian Agricultural Research Institute, incidents of stubble burning have plunged from 16,329 last year to just 8,515 in 2024, a remarkable shift from the 45,816 reported in 2020.