The AQI index assigns a quality score out of a maximum of 500.
Entry of heavy and medium goods vehicles in Delhi will be banned for three days beginning 11pm from tonight as the city's air quality worsened to the "severe-plus emergency" category following cracker burning on Diwali. A "severe plus emergency" level AQI essentially means that even healthy people may suffer from respiratory illnesses on prolonged exposure. This morning, the worst air was recorded by the centre in Bawana - 370, or "Very Poor" on the air quality index.
The contribution of PM2.5 and PM10 had increased from 50 per cent to 70 per cent last night, indicating an increased share of locally generated firecracker emissions, the Safar said.
On Friday, levels of particulates 2.5 micrometres or less in diameter, the most harmful to human health, peaked at 845, according to the U.S. embassy website that monitors air quality independently.
Patna, Bihar: The monitoring station at the planetarium complex in Bihar's capital city read 416 - also categorised as severe - on the morning after Diwali. This air will seriously affect those with ailments, according to a SAFAR advisory.
While other cities across north India recorded AQI scores of between 300 and 350, the air was significantly better in central and southern cities - with with the air in Thiruvananthapuram, Kerala, deemed "satisfactory" with a AQI score of only 64. India's official permissible PM2.5 limit is 60 ug/m3, while that of PM10 is 100 ug/m3.
The Supreme Court on Tuesday allowed the sale and manufacture of "green" firecrackers which have low emission across the country. The court said the police should ensure there was no sale of banned firecrackers and in case of any violation, the Station House Officer (SHO) of the police station of the area would be held personally liable and this would amount to committing contempt of court.
Despite the order, certain places reported violation of the specified time period. The areas where the violations were recorded included Mayur Vihar Extension, Lajpat Nagar, Lutyens' Delhi, IP extension, Dwarka and Noida Sector 78.