Vehicular population has increased by over 35 to 40 times in the last three decades, and the city has the highest per capita availability of vehicles.

Interestingly, 40% of the vehicles contributing to air pollution are the ones not registered in the city.

Autorickshaws are a major source of pollution. Despite the ban, about 1,500 autos from Mohali and Panchkula ply on Chandigarh roads.

"Police do not bar the entry of these autos from Punjab and Haryana despite the ban," says a city-based auto driver.

The autos which run between Panchkula and Chandigarh, and Mohali and Chandigarh create more pollution as most of them run on diesel.

Secretary of State Transport Authority Capt PS Shergill says, "Since we do not have a CNG petrol station, we will have to rely on diesel.

Petrol would be so costly that most autorickshaws would go off roads. While suspended particulate matter (SPM) level is not as bad as it is in other big cities, it is certainly higher than the permissible limits."

The suspect autos (which do not get pollution check done) are seldom put to smoke analyser test. As a result, there has been a rise in SPM level. While the permissible level of SPM is 140 micrograms, it is touching 250.

Sulphur dioxide (SO2) and nitrogen dioxide (NO2) levels have also gone up.

The figures available with Chandigarh Pollution Control Committee (CPCC) until 2005 show the air pollution level has crossed the permissible limits.

The SPM level in the commercial and industrial areas have gone up considerably.