A "very poor" AQI translates into spike in respiratory illnesses and if the air quality dips further, the AQI turns "severe", which troubles healthy individuals and seriously affects those with health issues. According to the SAFAR, the moisture in the air on Wednesday was normal, thus reducing the pollution load slightly.
In 2016, Diwali festivities raised pollution levels to their highest in almost two decades - forcing the closure of schools and other emergency measures.
"However, air quality is recovering from the afternoon and is likely to touch "very poor" range by night provided no additional local emissions are added anymore", it said in its report earlier Thursday.
After the Diwali festival, levels of airborne PM 10 and PM 2.5 touched 470 and 322 respectively, up from 438 and 180 in 2018, the Central Pollution Control Board said in a bulletin.
Delhi's pollution level post-Diwali almost doubled in comparison to a year ago and entered the "severe-plus emergency" category (ten times permissible limit) as people burst firecrackers before and after the Supreme Court stipulated time frame of 8 pm to 10 pm. These indices measure the concentration of tiny poisonous particulate matter.
This year, Diwali day shows that the PM10 and PM2.5 values have increased in Delhi compared to 2017.
The air quality began to deteriorate from 7 pm on Diwali evening.
The Supreme Court had allowed people to burst firecrackers from 8 pm to 10 pm only on Diwali and other festivals. India's official permissible PM2.5 limit is 60 µgm-3 while PM10 level is 100 µgm-3.
Air pollution in New Delhi hit hazardous levels Thursday after a night of free-for-all Diwali fireworks, despite Supreme Court efforts to curb the smog-fuelling partying.
In certain places, firecrackers were burnt before and after the set time frame, despite the Supreme Court's order.
Delhi has failed spectacularly in preventing the air quality from falling into the "severe-plus emergency" category the morning after Diwali.
The court had asked police to ensure that banned fireworks were not sold and said in case of any violation the commanding officer of the police station concerned would be held personally liable and it would amount to committing contempt of the court.
The areas where the violations were recorded included Mayur Vihar Extension, Lajpat Nagar, Lutyens' Delhi, IP extension, Dwarka and Noida Sector 78.