Delhi’s AQI reached 511 on Sunday morning, placing the city’s air in the hazardous category. AQI.in estimates that the pollution exposure is equivalent to smoking 12.5 cigarettes daily. Delhi's air quality index reached a hazardous 511, equating to smoking 375 cigarettes monthly, significantly increasing the risk of asthma and heart issues. London's AQI improved to 63 after a high pollution alert, while Delhi recorded 321 on November 12.