"Today the air quality in Delhi is in the 'poor' category. The wind speed is almost zero, particulate matter is not washing out, so the pollution is not getting dispersed. There will be an improvement in the coming days," Lal told ANI.
According to System of Air Quality and Weather Forecasting And Research (SAFAR), the overall air quality index (AQI) in Delhi was recorded at 364 till 4 pm, which falls in the 'very poor' category. The AQI showed marginal improvement after being in the 'severe' category for a couple of days owing to increased wind speed.
The AQI between the range of 51 and 100 is considered as satisfactory, 101-200 is moderate, 201-300 falls under the category of poor. 300-400 is considered as 'very poor' and range between 401-500 falls under the category as 'hazardous'.