India, Nov. 20 -- Only three cities in the country were in the throes of "severe" air on Wednesday - Ghaziabad, Greater Noida and Noida - while Delhi, Gurugram and Faridabad hovered just short of the danger zone as a thick, unmoving haze settled across the National Capital Region (NCR). Data from the Central Pollution Control Board (CPCB) showed Ghaziabad topping national charts with an AQI of 422, followed by Greater Noida at 420 and Noida at 409. Delhi's 4pm reading stood at 392, firmly in the "very poor" band and only nine points short of "severe". Gurugram and Faridabad were in the "poor" category, with readings of 300 and 265.

All 10 of India's most polluted cities on Wednesday were in NCR, underscoring how the national air-pollutio...