Air Pollution New Delhi
The World Health Organisation report suggests Gwalior is the most polluted city in India, not Delhi. Picture: Vendors selling drinks stand beside vehicles near the India Gate war memorial on a smoggy day in New Delhi Feb. 1, 2013.Reuters

Delhi's pollution levels are likely to turn 'severe' on Thursday, with air quality monitoring agencies warning of particulate matter in the capital's air reaching far above the safety limit. 

According to the System of Air Quality and Weather Forecasting And Research (SAFAR), the concentraion of particulate matter less than 2.5 microns in size (PM2.5) in Delhi's air is expected to reach 252 micrograms per cubic metre, while particulate matter up to 10 microns in size is likely to touch the 'severe' limit of 413.

These particulate matter are known to cause severe health issues, including respiratory problems, cardiac problems and even lung cancer. 

Delhi health minister Satyendar Jain reportedly said that the air pollution in the capital had reached 'fatal' levels. 

The reason for Delhi's air reaching its dirtiest state on Thursday is the deadly combination of cloudy skies and crop burning in neighbouring Haryana and Punjab that has caused smog to envelop the capital. 

Environment and health experts are reportedly calling for schools to be shut while the air pollution levels remain severe. 

The only relief for Delhiites is that the weather agencies have forecast a drop in pollution levels till the weekend.