The air quality in the capital remained "severe" for the second consecutive day on Thursday, with high particle pollutant in air and thick fog continue to choke the residents.

As per weather analysts, high humidity, light winds and low temperatures are the reasons why the particulate matter is not getting dispersed and continues to be major cause of pollution.

"Right now the wind, which are coming from the Bay of Bengal have moisture in it and the pollutants are getting mixed with it. This situation would improve within two to three days, as north-westerly dry winds are expected after two days," Mahesh Palawat, director of private weather forecasting agency Skymet, told IANS.

According to Sumit Sharma, fellow at TERI, the levels of PM 2.5 (particulate matters with diameter less than 2.5 mm) are three to five times higher than prescribed standards. 

"Other than Delhi's own pollution, sources in NCR and beyond also contribute significantly to Delhi's PM 2.5 levels. Gases like SO2 and Nox released from industries, power plants, vehicles and diesel generator sets also convert to particulates adding to the mass of PM 2.5. We suggest multi sectoral actions at regional scales and not merely in Delhi," Sharma told IANS.

He further added that the air purifiers being planned for traffic intersection will only have a limited impact on air quality in a very small area around the equipment, and that the city "needs more effective emission mitigation measures to reduce pollution levels all across the city".

The Delhi government has decided to install the air purifiers at six major traffic intersections of the city.

Central Pollution Control Board's data of the Air Quality Index (AQI) shows that the air quality of Delhi is slowly deteriorating.

The AQI on Thursday was 403 and in Faridabad was 431, which is labelled "severe". It was 410 or "severe" on Wednesday, 368 or "very poor" on Tuesday and 229 or "poor" on Monday.