The major pollutant that affects lungs and risks major health issues recorded a massive 140% jump in the 24-hour period since last morning as the air quality in Delhi deteriorated back to toxic levels a day after Diwali.
PM2.5, the most damaging of all particles present in the air, clocked an hourly average of 200.8 at 7 am. It was 83.5 at the same time yesterday, according to data recorded by the Central Pollution Control Board (CPCB).
The PM2.5 and PM10 pollutant levels touched 500 at most places during this period, including in Rohini, ITO, and Delhi airport area, showed CPCB data.
The air quality index (AQI) is derived from the value of six particulate and gaseous matter in the air. Of these, PM 2.5 is the main factor as it passes the nose and throat barrier, goes into the lungs, gets deposited there and gets absorbed into the blood, according to Dr Arvind Kumar, chairman of Institute of Chest Surgery at Medanta Gurugram.
PM2.5 and smaller particles are critical when it comes to damaging lungs and the rest of the body.
Delhi yesterday witnessed its best Diwali day air quality in eight years, but the AQI crossed 500 at most places this morning after the NCR region witnessed a widespread violation of the Supreme Court's cracker ban.
Read | Delhi Air Crisis Worsens As Diwali Fireworks Wipe Out Rain Relief
Realtime monitoring websites showed several places, including Lajpat Nagar and Jawaharlal Nehru Stadium, reporting an AQI above 900.
An AQI between zero and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', 401 and 450 'severe' and above 450 'severe plus'.
Supreme Court last week clarified that its order banning firecrackers containing barium binds every state and is not just limited to the Delhi-NCR region.
Several fire-related incidents were also reported last evening. Delhi Fire Service received 208 fire-related calls yesterday, including 22 related to crackers, said DFS chief Atul Garg.
Delhi, where the air quality ranks among the worst in the world's capital cities, was cloaked in a thick blanket of smog with severe pollution levels for a week since October 28. The government had to shut schools and ban diesel trucks in view of the pollution, though it stopped short of enforcing the odd-even rule.
The AQI stood at 218 in Delhi at 4 pm yesterday, the best in at least three weeks, with rains last week bringing about a slight improvement just ahead of the festival of lights.
