A thick haze engulfed Delhi as the air quality deteriorated, authorities said today, adding eight areas of the national capital recorded severe pollution level.
The overall air quality index (AQI) of Delhi was recorded at 360, which falls in the very poor category, according to the Central Pollution Control Board (CPCB) data.
CPCB added that 23 areas of Delhi recorded 'very poor' air quality.
In NCR, Ghaziabad recorded worst air quality with AQI 407
The CPCB said Dwarka Sector 8, Jahangirpuri, Mundka, Narela, Nehru Nagar, Rohini, Anand Vihar, and Wazirpur recorded severe air quality.
The level of PM2.5 (diameter less than 2.5 micrometers) was recorded at 211 and PM10 at 394.
While in NCR, Ghaziabad recorded the worst air quality at the severe level with an AQI of 407. Gurugram, Faridabad, and Noida recorded very poor air quality.
Know how quality of air is determined through AQI
An Air Quality Index (AQI), a number used to measure the pollution level in the air, between 0 and 50 is considered good, 51 and 100 satisfactory, 101 and 200 moderate, 201 and 300 poor, 301 and 400 very poor, and 401 and 500 severe.
Ventilation index extremely unfavorable for dispersion of pollutants today
According to the Indian Institute of Tropical Meteorology (IITM), a haze has engulfed the national capital and the wind speed and ventilation index are extremely unfavorable for dispersion of pollutants.
The ventilation index of around 6,000 sqm/second gets rid of pollutants, but it came down to 1,500 sqm/second today in the city.
Ventilation index determines how fast pollutants can get dispersed.
Air quality to remain 'very poor' for next two days
According to the System of Air Quality and Weather Forecasting (SAFAR), the air quality is very poor and will remain in the same category with a gradual increase in pollution level for the next two days.
"The increase in pollution can be attributed to the decline in wind speed as compared to past two days. All other meteorological factors were already unfavorable," said SAFAR.