Firecrackers behind 80% of Delhi's pollution post Diwali: Study
What's the story
A study by the Indian Institute of Tropical Meteorology (IITM) has revealed that firecrackers were responsible for over 80% of Delhi's pollution load on November 9, a day after Diwali. Stubble burning was not a major contributor, the IITM's assessment also indicates. The city was already grappling with high pollution levels from various sources before the festival. While the air quality improved slightly on Tuesday, it still remained in the "very poor" category with an AQI of 302 by evening.
Pollution assessment
Firecrackers contributed 71.1% of PM2.5 concentration on November 9
Per NDTV, a separate IITM source-apportionment assessment showed that firecrackers contributed 71.1% of PM2.5 concentration on November 9 between 1:00am and 9:00am.
This was a stark increase from their contribution of only 5.6% on November 7 and 9.3% on November 6.
PM2.5 levels at Jahangirpuri reached an alarming high of 4,985 micrograms per cubic meter at three am on November 9, while Nehru Nagar recorded a level of 2,808 micrograms per cubic meter.
Pollution assessment
Vehicular emissions accounted for only 6.9% of PM2.5 levels
In comparison, on November 9, vehicular emissions accounted for only 6.9% of PM2.5, while secondary inorganic and organic aerosols contributed 5 and 4.5%, respectively.
On Tuesday, firecrackers contributed 29.9% to Delhi's pollution between 1:00am and 9:00am, according to IITM. Secondary organic compounds were the second major contributors at 17.5%.
The AQI remained at 308 on Wednesday morning, in the "very poor" category.
Pollution sources
Delhi to see decline in concentrations of particulate matter
Favorable winds on November 10 helped disperse some of the accumulated pollutants, bringing down the AQI to 299 by afternoon before rising slightly again later in the day.
Mahesh Palawat, vice-president of Skymet, told PTI that a change in wind direction and speed had contributed to the improvement in air quality.
The Air Quality Early Warning System (EWS) also forecast a decline in concentrations of particulate matter, including PM2.5 and PM10, over the next two days.