NEW DELHI: Delhi will have poor air quality for next two to three days, due to dust storm building up in Oman, said officials of CPCB. Delhi's air quality was satisfactory last week. On Friday, the air quality index (AQI) was recorded at 235, which falls under the 'poor' category as per the Central Pollution Control Board (CPCB) data.
The PM10 (particulate matter) levels increased to settle at 261 micrograms per cubic metre (µg/m3) on Thursday. This is over two times the prescribed standard of 100 µg/m3. PM2.5 was in the moderate category at 67 µg/m3. An AQI between 0-50 is considered 'good,' 51-100 'satisfactory,' 101-200 'moderate,' 201-300 'poor,' 301-400 'very poor,' and 401-500 'severe.'
According to experts, the reason for the sudden 'poor' air quality is the percolation of emissions at a faster rate after the rain showers in the city.
"The atmosphere was totally cleaned up owing to the continuous rains, which washed away the pollutants. Hence, a vacuum was created that has let the emissions to percolate faster. There was a space created for the pollutants, which accumulated faster and hence the air quality turned poor in just a few days," said Gufran Beig, the project director of SAFAR (System of Air Quality and Weather Forecasting and Research).
"The dominant pollutant, however, is PM10, which is less dangerous. It is likely to increase further in the next three days as per our prediction," he added. As per SAFAR's forecast, the levels of PM10 are going to increase to 287 µg/m3 on Friday.