Air quality across North India plunged into the ‘severe’ zone on Monday, with Haryana's Bahadurgarh worst hit. Pollution levels spiked across five states despite the activation of GRAP Stage 3 emergency restrictions. New Delhi: Bahadurgarh in Haryana recorded the highest air pollution level among the listed cities, with a 24-hour average Air Quality Index (AQI) of 400 at 4 pm on Monday, placing it in the 'very poor' category, according to the.