However, firecrackers burst late in the night caused sharp spikes in a few areas. Mumbai: The city’s air was much cleaner overall on Monday after Diwali, with govt and private trackers showing low pollution numbers.
Deonar’s PM10 went from 93 in the evening to 426 at 11pm. Andheri East saw PM2.5 jump from 39 at 8pm to 145 by 11pm. As the night went on, pollution shot up suddenly in select spots. On the other hand, areas like Ghatkopar, Colaba and Byculla saw no major jump at night, ending the festival on a cleaner note.
experts noted that their overall contribution to the city’s yearly average is tiny—around 1% While firecrackers can temporarily drive up local pollution by 50% to 60% for a few hours. “Firecrackers can temporarily dominate local pollution levels, sometimes contributing 50-60% or even more of the particulate pollution during peak hours in severely affected locations. Their impact can last 6-8 hours, depending on meteorological conditions. Weighing in on how citizens should read extremely high local pollution numbers, Gufran Beig, chair professor at Indian Institute of Advanced Studies, said: “Cracker-induced pollution numbers are bad for 1-2 hours only, giving figures like 600 momentarily. rolling 24-hour averages should be captured instead of hourly readings While publishing AQI numbers.
The exact contribution varies by location, emission inventory and averaging period,” said independent meteorologist Abhijith Modak. The 24-hour average helps in understanding if the high numbers are a perennial high or just momentary. ” He said hourly readings “don’t really mean much and they only lead to momentary outrage for 2-3 days and a complete lack of interest thereafter throughout the year”. “On the other hand, govt AQI data needs to be more citizen and layman friendly so that common people understand what it represents.”
But, their contribution to annual average pollution is considerably smaller. Beig asked that a regulatory body look into the numbers being put out by private portals.