Intermittent rain washed away pollutants and significantly improving the national Capital’s air quality which was in the ‘moderate’ category on Tuesday, authorities said.
The air quality index (AQI) of the city was recorded at 138 on Tuesday according to the System of Air Quality and Weather Forecasting and Research Institute (SAFAR), while the Central Pollution Control Board recorded Dehi’s AQI at 147.
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 overall air quality in Delhi was in the “moderate” category due to rains. The level of PM2.5 (particles in the air with a diameter of less than 2.5 micrometres) was recorded at 64 and PM10 at 156, the SAFAR said.
“Air quality will improve further and touch satisfactory by Wednesday due to cloudy sky and light rains/thunderstorm. However, SAFAR model predicts that AQI may deteriorate to ‘poor’ by May 17 as upper winds are likely to be favourable to bring some impact of stubble burning from north india which are at its peak as per the fire counts. However, unlike winter, winds are fast enough to disperse the pollutant squickly,” the SAFAR said.
Delhi’s air quality was oscillating between ‘very poor’ and ‘severe’ for the last few days due to a dust storm in northwest India which led to a sharp increase in the PM2.5 level.
