Air Pollution Trend and Variation during a Mega Festival of Firecrackers (Diwali) in Context to COVID-19 Pandemic

The present study was conducted in Lucknow city to assess the impact of firecracker burning during Diwali, from 2 November 2021–6 November 2021 including the pre and post-Diwali days. The concentrations of PM₁₀, PM_2.5, SO₂, NO₂, CO, O₃, benzene and toluene, were monitored from the Central Pollution Control Board site on an hourly basis. The Air Quality Index was also recorded for PM₁₀, PM_2.5, SO₂ and NO₂. A questionnaire survey was done with 51 doctors to know the reported complaints post-Diwali. On Diwali night the PM_2.5 value reached 262 µg m⁻³ around 22:00 hours and the maximum value (900 µg m⁻³) was obtained on 5 November, reported from the Central School monitoring station. From Gomti Nagar highest PM_2.5 value obtained on Diwali day was 538 µg m⁻³ at 23:00 hours reaching 519 µg m⁻³ post-Diwali. Areas belonging to the old part of the city witnessed higher variations as PM_2.5 crossed 900 µg m⁻³, in Lalbagh and Talkatora areas. The multivariate analysis showed that on Diwali night there was an increase of 204, 386, 344 and 341 in the PM_2.5 concentration reported from Gomtinagar, Central School, Talkatora and Lalbagh stations, showing that firecracker burning resulted in a significant increase in air pollution. The Toluene/Benzene ratio was mostly more than 1 indicating that toluene and benzene may be emitted from other sources as well including the mobile sources. Around 50–75% rise was seen in the number of patients post-Diwali. 57.1% of the reported cases had respiratory issues, followed by allergic reactions. The data obtained from Lalbagh, Talkatora and Central School showed that although the values remained high, a decreasing trend was seen in the AQI compared to previous years which is a good sign and may be attributed to public awareness and the ongoing pandemic making people conscious.