An analysis of hour-by-hour particulate matter levels in 2023 shows that many Indian cities registered this year’s highest pollution levels around Deepavali day (November 12). In seven Indian cities analysed — Delhi, Noida, Gurugram, Lucknow, Ahmedabad, Chennai, and Kolkata — the hourly pollution levels crossed the 500 micrograms per cubic meter ( μg/m3) mark around Deepavali day.
Pollution during Deepavali spikes due to firecrackers. The Chest Research Foundation of India in Pune carried out experiments in 2016 to measure the amount of PM 2.5 particles released by firecrackers during Deepavali. The experiments showed a significant increase in pollution, with the snake tablet firecracker emitting a peak level of 64,500 μg/m3 of PM 2.5, which are tiny particles with a diameter of 2.5 microns or less.
Chart 1 | The charts shows PM 2.5 levels in μg/m3 recorded every hour between January 1, 2023 and November 14, 2023 in a measuring station across select cities. Each circle in the chart depicts the average PM 2.5 level in a one-hour period in a city. The higher a circle is placed, the more the PM 2.5 particulate level. Hourly readings just before, after, and on Deepavali day are highlighted. The highest-ever pollution level recorded in an hour just before, after, and on Deepavali day is annotated in the graphs.
