After brief respite, Delhi air quality ‘poor’ again

New Delhi: Days after the national capital recorded “good” air quality, the pollution levels increased in the city making it a “poor” air quality day once again.

On Thursday, 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 as per Safar, which comes under the ministry of earth sciences.

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.

Last Friday, for the first time this year, Delhi saw “good” air quality owing to continuous rains in the city.

The incessant showers managed to wash away the pollutants in Delhi’s air, giving the national capital its first “good” air quality day.