Delhi's air quality index (AQI) stood at 326 at 6 am today,
Delhi's air quality turned 'very poor' this morning - a day after Diwali - but the pollution levels were relatively better than the previous years, the data shows.
As per the Central Pollution Control Board (CPCB), the city's air quality index (AQI) at 312 on Monday was the lowest in four years and the second-best in seven years for a Diwali day.
The air quality, however, worsened overnight with firecrackers being set off in several parts of the national capital despite the ban. While the city's AQI stood at 323 at 6 am today, the PM 2.5 levels were five to six times the national standard.
In neighbouring Gurugram, Noida and Faridabad too, the air quality slipped into the 'very poor' category.
The national capital had recorded an AQI of 382 last year; 414 in 2020 and 337 in 2019.
An AQI between zero and 50 is considered "good", 51 and 100 "satisfactory", 101 and 200 "moderate", 201 and 300 "poor", 301 and 400 "very poor", and 401 and 500 "severe".
The Delhi government had banned the production, storage, sale and bursting of firecrackers this Diwali after considering environmental concerns and health hazards associated with it. Those caught violating the ban would be fined and jailed for six months, the government had said.
Last week, the Supreme Court had also refused to lift the ban on firecrackers in Delhi citing pollution.
"How can we allow firecrackers even if they are green crackers? Have you seen the pollution of Delhi?" the Supreme Court had asked - turning down BJP MP Manoj Tiwari's plea against the Delhi government order.
The AAP government had banned the sale and use of firecrackers last Diwali too due to concerns over alarming air pollution levels.
In addition to firecrackers, air pollution in Delhi during the Diwali period is made worse by stubble burning - a contentious practice - in neighbouring states like Haryana and Punjab.
Emissions from firecrackers and farm fires have contributed significantly to Delhi's PM2.5 pollution on Diwali over the years. Experts say their share this year was relatively less than previous years.
Another important factor behind the largely stable air quality situation this Diwali was moderate wind speed that did not allow rapid accumulation of pollutants.