Air was worst on Tuesday morning
It was around 9pm that the average levels PM2.5 of almost all stations hit the severe zone. From that point, there was no looking back. It continued to deteriorate throughout the night.
SENIOR CPCB OFFICIAL
NEWDELHI: Though the city reeled under “severe” categories of pollution throughout Tuesday, the period between 9am and 1pm was the worst.
Data available with the Central Pollution Control Board (CPCB) shows that between 9am and 1pm on Tuesday, the average level of PM2.5 — ultrafine particles that can penetrate deep in our lungs — shot the maximum.
“The average level of PM2.5 during this time of the day was at least 10 times that of safe standards. In some stations such as Siri Fort, Lodhi Road and DTU, the level had shot up by at least 15 times in this period,” said D Saha, head of the air quality laboratory of CPCB.
While places like Shadipur, DTU, Delhi University, Mathura Road, Lodhi Road, Siri Fort were worst polluted, the air quality was comparatively cleaner in areas such as Aya Nagar, Pusa Hills, among others.
On Monday, the average level of PM2.5 at CPCB stations was hovering around 121 micrograms per metre cube, which is considered to be in the “moderate to poor” category. Delhiites have rarely got cleaner air during this time of the year.
However, things started turning bad around 9pm on Monday when the city was engulfed by smog-like conditions.
“It was around 9pm that the average levels PM2.5 of almost all stations hit the severe zone. From that point, there was no looking back. It continued to deteriorate throughout the night,” said a senior CPCB official.
At around 10pm on Tuesday, PM2.5 levels first touched the “severe+” or “emergency” level. By that time the levels of PM2.5 had shot up by nine times in several areas such as DTU, Punjabi Bagh and Anand Vihar.
In the next few hours, pollution levels in most of the CPCB’S monitoring stations started deteriorating one after the other.
Some relief finally came at around 2pm on Tuesday, when PM2.5 levels again started improving. The level which had shot up by 10 times above the safe limit nearly halved by around 3pm on Tuesday.