Delhi experienced a surge in pollution levels on Monday morning as residents flouted the ban on firecrackers during Diwali. On Diwali day, the city had recorded its best air quality in eight years, with the Air Quality Index (AQI) at 218. However, the celebrations turned detrimental to the air quality as firecracker bursting during the night led to increased pollution amid low temperatures.
The AQI, which stood at 275 (poor category) at 7 am, gradually rose to 322 by 12 noon. Some areas, including Ayanagar, Central Road Research Institute, and Pusa, saw pollution levels near the ‘severe’ category, with AQIs between 400 and 450. The concentration of PM2.5, a fine particulate matter that can penetrate deep into the respiratory system and cause respiratory problems, exceeded the safe limit of 60 micrograms per cubic meter by six to seven times in these areas.
The early morning hours saw the PM2.5 concentration exceeding 1,000 micrograms per cubic meter in places like Okhla and Jahangirpuri. The Delhi Pollution Control Committee (DPCC) recorded a PM2.5 concentration of 1,423 micrograms per cubic meter at the Jawaharlal Nehru Stadium at 2 am, which gradually decreased to 101 micrograms per cubic meter by noon due to rising temperatures.
Similarly, the PM2.5 concentration at Okhla was 1,629 micrograms per cubic meter at 1 am and dipped to 157 micrograms per cubic meter by noon. At Anand Vihar, the air quality monitoring station recorded a PM2.5 concentration of 1,985 micrograms per cubic meter at midnight.
Comparing the AQIs on Diwali day in the last few years, Delhi recorded an AQI of 312 last year, 382 in 2021, 414 in 2020, 337 in 2019, 281 in 2018, 319 in 2017, and 431 in 2016, according to data from the Central Pollution Control Board. The day after Diwali saw AQIs of 360 in 2015, 445 in 2016, 403 in 2017, 390 in 2018, 368 in 2019, 435 in 2020, 462 in 2021, and 303 in 2022.
The improvement in air quality just before Diwali this year was attributed to intermittent rainfall and favorable wind speeds for pollutant dispersion. Prior to Diwali, the city experienced very poor to severe air quality for two weeks, with a suffocating haze enveloping the national capital.
Delhi has implemented a comprehensive ban on the manufacture, storage, sale, and use of firecrackers within the city for the past three years. Last year, a decrease in stubble burning incidents, delayed rain, favorable meteorological conditions, and an early Diwali prevented the city from experiencing severe pollution.
A numerical model-based framework called the Decision Support System estimated that stubble burning in neighboring states like Punjab and Haryana accounted for 35% of the PM2.5 pollution in Delhi on Sunday. The contribution is likely to be 22% on Monday and 14% on Tuesday. Transport in the city also contributed 12 to 14% to the pollution levels in recent days.
