Delhi sees another ‘good’ air day, likely to hold for 3 days
The national capital breathed a second consecutive “good” air day on Sunday as rain in and around NCR kept particulate matter (PM) down.
The Air Quality Index (AQI) value remained at 49, the same as Saturday, which is considered to be “good” on the scale. The last time the city had breathed air this clean was on July 31, 2017, when the AQI was at 47. Any reading of up to 50 on the index is considered to be an indicator of good air quality.
The AQI is expected to remain in “good” category for the next three days, as more rainfall is expected, said a statement issued by Safar on Sunday.
For past 10 days this month, between August 6 and August 16, the air quality has been in the “satisfactory” category. Safdarjung Obesrvatory, which represents Delhi’s weather, recorded 47.7 mm rainfall over the past 33 hours.
“The overall air quality is in good category. Widespread rainfall in and around NCR continued to positively affect the air quality scavenging suspended aerosol in the air. Also, increased rainfall activity from west to north interacting with a Western Disturbance has triggered the spell of good air quality days,” said Safar, pollution forecasting agency under the union Ministry of Earth Sciences.
Also, levels of the two most prominent polluters of Delhi – PM10 and PM2.5 – dropped further from yesterday. PM10 and 2.5 are particulate matters of less than 10 and 2.5 microns in size that can enter the respiratory system and cause health complications.
While the daily permissible limit of PM10 (coarse naturally occurring dust particles) is 100ug/m3, at 4pm on Sunday the level of the pollutant was around 23.4ug/m3 against yesterday’s 28 ug/m3. The permissible limit of PM2.5 (finer particles that are typically emitted by vehicles and industries) is 60ug/m3; its level dropped to 11.7ug/m3 around the same time from 12ug/m3 on Saturday.
According to experts, this is a rare ‘good’ air day spell in Delhi, which is mainly induced by a cumulative impact of widespread rain and winds in and around the periphery of the city.
“Rain and strong winds in and surrounding regions have not allowed pollutants to travel to Delhi. Suspended particulate matter in the air is being washed down by intermittent rain, which has resulted in good air quality for two days,” said a senior Central Pollution Control Board (CPCB) official, who did not wish to be named.
Overnight showers in the city also brought the mercury down. On Sunday, maximum temperature was 29.7 degrees Celsius, four notches below the season’s average while minimum settled at 24.8 degrees C.