An air emergency was declared in Delhi with its air quality index plummeting into ‘severe’ days ahead of Diwali. #WATCH | Thick layer of smog engulfs Delhi as Air Quality dips into 'Severe' category pic.twitter.com/xHQ8x5YVZe — ANI November 3, 2023 Since an AQI of 400 or more is classified as ‘severe’, the authorities have taken action in response to the …