New Delhi, Oct 30 : The air quality in Delhi and the National Capital Region (NCR) on Tuesday deteriorated further after an overnight spike in Particulate Matter (PM) with experts cautioning people to abstain from any form of brisk physical activity even indoors.
The city's Air Quality Index (AQI) at 11 a.m. was 398 points against 367 points on Monday and 366 on Sunday and in the "severe" category. However, it varied in different parts of the city.
The AQI for Ghaziabad was worst in the entire NCR region at 444 points, up by 14 points from Monday and remains in the "severe" category. In Gurugram, the AQI was 422, while it was 410 in Noida.
In Anand Vihar, the AQI was 450 which will affect healthy people and seriously impact those with existing diseases. Similarly, at the same time, the AQI at Rohini was 451 and at Jahangirpuri it was 453, worst in the entire NCR.
PM2.5 for Delhi was 261 points while PM10 was 471 points, whereas, in Delhi NCR, PM2.5 was 254 and PM10 was 458 points.
According to the Central Pollution Control Board, for severe air quality, PM2.5 must be between 250-300 or PM10 between 430-500.
The city witnessed a thick layer of haze on Tuesday morning which affected visibility.
"It is haze since ozone is at a good level," K.J. Ramsh, IMD Head, told IANS.
However, some called it a mixture of haze and smog, but more haze.
"Haze is the reflection of sunlight when it falls on PM and smog is a mixture of fog and PM," Shambhavi Shukla, a research associate with Centre for Science and Environment said.