It's winter and Delhi's air is heavy with toxic dust particles that travel to the deeper parts of your lungs, making you sick.
Government data shows that the levels of particulate matters are over 300% more than levels considered tolerable for public health.
The Indira Gandhi International Airport and nearby areas, Mandir Marg in central Delhi, RK Puram in the south, Civil Lines in the north, Punjabi Bagh in the west and Anand Vihar in the east are all choked with particulate matters - PM 10 and PM 2.5. The numbers represent their size in microns that are several times tinier than the diameter of human hair.
Official records show the levels are much more than what they were a year ago.
"Rise in the number of vehicles is responsible for this. That apart, the meteorological conditions are such that it is more harmful to humans now than during rest of the year," said Dharmendra Kumar, Delhi environment secretary.
In winter, the mixing height of air pollutants in atmosphere is lower because of inversion effect. At the IGI airport, for instance, the mass concentration of PM 10 and PM 2.5 were 322 microgrammes per cubic metre, against a prescribed standard of just 100.
The level of PM 2.5, which is a more harmful particulate matter, stood at 156 microgrammes per cubic metre while the standard is only 60. Conventionally particulate matter concentration of this magnitude showed up in traffic-heavy areas, such as ITO, Chandni Chowk, Ring Road and Kashmere Gate, in yearly pollution reports.
"Nowadays there is not much difference between commercial, traffic-heavy and residential areas in terms of pollution watch and control," he said.
The rise is of particulate matters in the air is bad news for children and the elderly as the particles travel to the deeper parts of the respiratory tract and could also cause a host of pulmonary ailments, said Dr TK Joshi, head of Delhi government's Centre for Occupational and Environmental Health.
According to a Central Pollution Control Board study in 2008, Delhi's children are increasingly falling prey to rising pollution levels.
"Diesel vehicles are more to blame because of toxic aldehyde emissions from the engines. World over the rise of PM 2.5 is attributed to diesel vehicles. Delhi's yearly pollution charts indicate an alarming rise in the combustion of this type of fuel, which needs to be checked," Joshi said.