Variation in Criteria Air Pollutants during Major Firework Festival and Significance of Transboundary Air Mass Movement on Air Quality in Megacity of Northern India

Abstract:

Globally, a number of firework events have been celebrated on a large scale in the names of different festivals. Diwali is one among the popular Indian festival held during October or November every year with huge fireworks. In the present study, various criteria air pollutants like nitrogen oxides (NOx), particulate matter (PM_2.5 and PM₁₀) and ozone (O₃) were analyzed in pre, during and post Diwali in two consecutive years i.e. October 2016 and October 2017 in one of the megacity of Northern India. The results showed that the background values of particulate matter are exceeding 5 to 6 times in 2016 and 7 to 8 times in 2017 than permissible limits set by NAAQS, India. In Diwali-2016, the highest PM₁₀ and PM_2.5 concentrations were about 8 times and 7 times higher than National Ambient Air Quality Standards (NAAQS) limits respectively. For Diwali-2017, there was rapid increase in PM₁₀ and PM_2.5 concentrations that were about 10 times and 13 times higher than NAAQS threshold value respectively. Moreover, PM₁₀ and PM_2.5 concentrations in 2017, higher than 2016 were found to be 5-8 times more as compared to background concentrations. Similarly, the concentrations of NO_x and O₃ also strongly influenced by fireworks induced air pollution in both the years of 2016 and 2017. The huge Diwali induced air pollution is influenced by transboundary air mass movements from nearby regions of megacity, Delhi and adjoining countries in both the selected years of 2016 and 2017. The study also conclude that during background and in and around Diwali period receives the air masses containing the emissions from biomass burning which significantly increases the air pollution load.