Expressing concern over the unprecedented smog over Delhi, the cabinet today instructed the Environment Secretary to explain its causes in the Capital.

While briefing the media after the cabinet meeting, Chief Minister Sheila Dikshit said that its primary reasons are slow wind speed, low temperature and high humidity. These conditions appear to have led to high-dust concentration and higher concentration of oxides of nitrogen.

Besides, burning of rice husk, straw in agricultural fields in Punjab, Haryana and UP has also contributed to the smog. With the change in wind speed, it is likely to disperse.

She stated that there is no increase in pollution load from the sources of air emission in Delhi as compared to the previous years. Delhi has stringent air pollution norms. There are no polluting industries in the city as they have been shifted to the NCR region, she said.

The Environment Department has decided to get a comprehensive study done for knowing various air pollutants and their role in causing pollution. The study will also suggest measures to improve the quality of air. The IIT Kanpur will conduct the study.

What's more, Delhi Pollution Control Committee has established real-time air monitoring stations and the data is available in public domain.

The cabinet also directed the Environment Department to take up the matter with the Union Ministry of Environment and Forests and the NCR Planning Board in order to find out the sources of pollution and its movement towards Delhi.