NEW DELHI, Jan. 9 (Xinhua) -- The air pollution level in the Indian capital territory New Delhi on Monday became severe, prompting local authorities to put curbs on some vehicles until Friday, local media reported.
According to the Central Pollution Control Board (CPCB), the overall air quality index (AQI) turned severe at 444.
"The AQI in Delhi at 8:00 p.m. (local time) today was recorded at 444," data released by CPCB said. "The air quality is very poor and prominent pollutants are PM 2.5 and PM 10."
Experts say PM 2.5 are fine particles that are 2.5 microns or less in diameter and can travel deep into the respiratory tract, reaching the lungs and entering the bloodstream.
Meanwhile, the local government in view of the worsening air quality in Delhi has decided to impose a temporary ban on plying of BS-III petrol and BS-IV diesel vehicles in the national capital from Tuesday.
The BS is the short form of Bharat Stage, a government-instituted emission standard for four-wheelers.
Keeping in view the severe category of Delhi's AQI, health experts have advised residents to stop outdoor activity in the early morning and after sunset times, besides avoiding prolonged or heavy exertion.
As per CPCB, AQI between 0 - 50 is considered "good", between 51 - 100 "satisfactory", between 101 - 200 "moderate", between 201 - 300 "poor", between 301 - 400 "very poor", and between 401 - 500 "severe" and beyond 500 is severe plus emergency.
Air pollution continues to worsen in New Delhi and it gets aggravated during winter months. The deterioration in air quality is attributed to slow wind speed and stubble burning (farm fires) in the neighboring states. ■
