LUCKNOW, Nov. 25 -- Uttar Pradesh's Hapur district emerged as the most polluted city in India on Monday, registering an Air Quality Index of 416 in the Central Pollution Control Board's (CPCB) 4 PM bulletin. It was the only city to fall in the 'severe' category among 241 monitored locations, standing out as the darkest red spot on the national air map.

Delhi, often among the country's worst performers, recorded a very poor 382, still below Hapur's reading.

Meanwhile, Lucknow's air also worsened, slipping back into the 'poor' bracket with an AQI of 208, the city's fifth such day this month. The last poor reading was on November 16 at 227, while the highest this month was 254 on November 5. Monday's figure marked the third-highest level f...