The<a href="https://www.thenationalnews.com/tags/india/" target="_blank"> Indian</a> capital closed all schools, banned lorries and halted construction work on Monday as air quality in New Delhi plummeted to its worst level this year, with a thick layer of yellowish haze engulfing the city of 22 million. Air pollution was recorded in the “severe plus” category, with the average Air Quality Index across <a href="https://www.thenationalnews.com/news/asia/2024/11/13/delhi-pollution-aqi-smog/" target="_blank">New Delhi</a> hovering at about 480 in the morning. Some areas recorded readings off the charts, breaching the measurable 500 mark. Swiss technology company IQAir, which analyses global pollution data, recorded an air quality index of 1,743 in the afternoon whereas the US Embassy in New Delhi—which uses the Environmental Protection Agency’s AirNow chart—recorded the AQI levels at above 1,600. Any figure above 50 is considered harmful, with 300 or above deemed a health hazard. Visibility dropped to just 150 metres. The smog forced authorities to shut all schools following their decision last week to <a href="https://www.thenationalnews.com/news/asia/2024/11/15/delhi-pollution-schools-online-restrictions/" target="_blank">close only primary schools</a>. The city government said children would move to online learning. Officials also invoked strict mitigation measures in an effort to control the pollution. Following advice from <a href="https://www.thenationalnews.com/news/asia/2024/11/14/delhi-pollution-aqi/" target="_blank">India's</a> Commission for Air Quality Management, authorities banned all public construction work and the entry of diesel-run commercial vehicles into the urban area. The commission urged officials to also consider shutting colleges and other higher educational institutions and begin reducing the number of vehicles on the streets. It also recommended that half of all government employees work from home. <a href="https://www.thenationalnews.com/news/asia/2024/11/01/delhi-pollution-aqi-diwali/" target="_blank">New Delhi</a> has seen a gradual deterioration in <a href="https://www.thenationalnews.com/news/asia/2024/10/30/delhi-aqi-pollution-toxic-smog/" target="_blank">air quality since late October</a> – an annual autumn and winter phenomenon in the world’s most polluted capital. But the smog suddenly worsened at the weekend as cold temperatures gripped the city, bringing a layer of fog that mixed with pollutants and smoke from crop burning on farms. Experts say air quality readings between 400 and 500 on the government's scale are equal to smoking 25 cigarettes a day. The concentration of PM2.5 – fine particles in the air blamed for lung and heart diseases – has reached 527 microns per cubic metre in New Delhi, more than 100 times the safe limit set by the World Health Organisation. The Supreme Court came down heavily on the city government and Prime Minister Narendra Modi’s federal government for its failure to curb the pollution crisis and ordered them to take all possible measures to bring down the pollution levels. "It is the constitutional obligation of the central government and state governments to ensure the citizens live in a pollution-free atmosphere. All possible actions shall be taken at the level of these governments to ensure that the AQI is brought down,” the Supreme Court said on Monday, adding that the AQI level inside the courtroom was 990. It further added that scaling down preventive measures to tackle pollution would require the top court’s permission. Large swaths of India’s northern states were reeling under distressing air pollution levels. Delhi’s neighbouring states of Punjab, Haryana and Uttar Pradesh where the Taj Mahal, the 17th century Mughal mausoleum in Agra city, remained shrouded in smog as AQi levels hovered at about 300.