The national capital's air quality fluctuated between "poor" and "very poor" categories on Friday, and was expected to decline sharply over the weekend owing to changing weather and "significant" stubble burning.
The overall air quality index (AQI) in the city stood at 306 at 9 am on Friday. It improved by 64 points and was recorded at 242 at 9 pm.
At the start of the day, the overall AQI at DTU, Dwarka Sector 8, Narela, Wazirpur and Bawana was 312, 316, 310, 312, and 341 respectively, which falls in the "very poor" category.
Only Bawana recorded its AQI (320) in the "very poor" category in the evening.
An AQI between 0 and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe.
The Ministry of Earth Sciences' air quality research and forecast service, SAFAR, said, "Under the influence of a western disturbance, surface wind speed has increased. Increased ventilation coefficient has lead to ...
