Dense smog continued to enshroud Delhi and the National Capital Region (NCR) on Sunday, with pollution level remaining in the 'severe' category.
At 9:00 am, PM 10 Average Levels (24 Hourly) were recorded at 671 micro grams/m3 Counter, while PM 2.5 Average Levels (24 Hourly) were recorded at 441.7 micro grams/m3 Counter, as per Graded Response Action Plan (GRAP).
In Delhi's Lodhi Road area, PM 10 levels were at 560, and PM 2.5 at 625. In Noida, PM 10 levels were at 551, and PM 2.5 levels at 541.
The air quality is categorised as 'severe', when pollution level hits 401 or above, in the Air Quality Index (AQI).
The city's air quality worsened ahead of winter as cooler air traps pollutants near the ground, preventing them from dispersing into the atmosphere.
The Central Pollution Control Board (CPCB) has identified four reasons for the sudden onset of pollution - temperature, wind speed, relative humidity and atmospheric boundary layer - for the worsening Delhi air.
Meanwhile, the Health Ministry has also issued an advisory, asking citizens to drink plenty of water and avoid areas with smoke or heavy dust.
The National Green Tribunal (NGT) has banned construction, one source of particulate matter pollution, in the region through November 14, whereas truck and car travel has also been limited.
To this end, trucks and heavy vehicles were barred from entering into Delhi last night.