India, Nov. 9 -- Delhi on Monday morning witnessed heavy smog as the air quality remained in the 'severe category'.

According to reports, the Air Quality Index (AQI) is at 472 in the 'severe' category at ITO. Whereas, AQI is at 449 in Major Dhyan Chand National Stadium area.

AQI is at 484 in Anand Vihar, 470 in Mundka, 465 Okhla Phase 2 and 468 in Wazirpur, all in 'severe category'.

An AQI between 0-50 is considered 'good', 51-100 is 'satisfactory', 101-200 'moderate', 201-300 'poor', 301-400 'very poor' and 401-500 is considered as 'severe/hazardous'.

Published by HT Digital Content Services with permission from Tehelka....