Almost two years after CNG was introduced in Delhi, the Capital's air still remains far from being safe, pollution control experts say, warning it could spell health problems for people suffering from various respiratory disorders.
The findings of the Central Pollution Control Board (CPCB) show a considerable decrease in the Sulphur Dioxide (SO2) levels in the air. But there has been an increase in the Nitrogen Dioxide (NO2) levels.
The increase in the levels of NO2 has raised the possibility of serious health hazards for the Delhiites.
"NO2 is a strong oxidising agent that can irritate the lungs and decrease the resistance to respiratory infection. It is particularly dangerous for people with asthma and bronchitis", says Dr SK Chabra, Department of Cardio-respiratory Physiology, VP Chest Institute.
According to the study, the level of NO2 concentration in the ITO intersection in the city ranged from 70 to 102 microgram per cubic metre in the first week of February this year, whereas the standard limit is 80 microgram per cubic metre. During the same period in 2002, this figure ranged from 72 to 85 microgram per cubic metre.
"The primary reasons for the increase in the levels of NO2 are the increase in the number of vehicles in Delhi and the emissions from the industrial units. Poor maintenance of the CNG vehicles is another factor contributing to the increase in NO2 levels", says Anumita Roychowdhury, Associate Director, Centre for Science and Environment (CSE).
