Thanks to poor monitoring. Majority of vehicle owners don't even bother to get their vehicles checked.

The result is quite palpable. A frequent breathlessness, round-the-year sore throat, a thick layer of soot in your nostril - well these are just some of inescapable signs of polluted ambient air of Kolkata.

Declared as one of the worst polluted metros in India by World Health Organization (WHO), one would wonder the relevance of the stringent emission norms applicable for the city.

The figure compiled by the Indian Council of Medical Research (ICMR) for 2009-11 only vindicates the revelation of WHO. ICMR concludes, while putting 'air pollution' of Kolkata in the same category as tobacco, that UV radiation and plutonium are lung cancer causing agents.

The state has banned commercial vehicles older than 15 years from the Kolkata metropolitan area (KMA). Autos switched to LPG. After April 2010, only Bharat Stage-IV vehicles can be registered in the city. The area around Victoria Memorial, too, has been declared a no-go zone for buses and heavy vehicles. Yet, there is no noticeable improvement in the air quality. The pollution parameters are 20% to 50% higher than safe limits at many parts of the city.

The reason is only 24% vehicles are actually turning up for the pollution-under-control (PUC) certificate. There has been hardly any enforcement since the initial days of the ban on 15-year-old commercial vehicles in 2008-09. What makes it worse is the fact that many of the auto emission testing centres (AETC) have not been properly calibrated and a clean chit from them may not necessarily mean a green chit.

"With no enforcement in vogue, the urgency of getting a PUC certificate has somehow been lost," said an emission tester. Also, unlike Mumbai and Delhi, where renewal of PUC is a quarterly affair, in Kolkata it is bi-annual.

Besides, not all AETCs comply with the rules, say sources. "In Kolkata, 50% AETCs have not renewed their licences and nearly 80% have no annual maintenance contracts. Hence, their reports will always be in doubt as the machines are not calibrated," said auto-emission consultant Somendra Ghosh.

According to the Auto Emission Testers' Association in West Bengal, only 24% of the city's vehicular population turns up for the half-yearly check. "The vast majority of vehicles go unchecked and continue to pollute the city, putting a big question mark on the relevance of the stringent emission standards," said association general secretary A Pal Chowdhury.

"The government seems to have forgotten the basics. If people do not follow a law, it does make any difference if you have stringent or lax rules. The government has failed miserably in enforcement of pollution rules," said a tester.

It is the responsibility of the transport department to enforce the law. The penalty for the first offence of not having PUC clearance is Rs 1,000 and the same is Rs 2,000 for subsequent offences. The second time, the registration of the vehicle can be suspended for 15 days and if the owner fails a third time, the registration may be cancelled for life. But there is no system yet to check for repeat offences. So, even the few, who are caught, get off with Rs 2000-fine.

"We do not have enough inspectors for raids. The Pollution Control Board is supposed to check if the AETCs are functioning properly," an official of the public vehicles department said.

Experts say that the proper introduction of smart cards would lead to better monitoring of emission tests. The moment a vehicle undergoes an emission test, the smart card would record it, which would show up in the PVD database. It will be easier to identify errant vehicles and repeat offenders.

"Compliance has, in fact, worsened after the upgrade of testing centres from the old mono-gas system to computerised multi-gas analysing system. It is a pretty hopeless situation with air pollution assuming serious proportions," said another tester.

The problem is even worse in the districts. The entire state has only 59 AETCs, of which 47 are in Kolkata. Districts like Hooghly and Nadia have only one AETC each. And, north Bengal has none. This unequal distribution of AETCs has made PUC certificate out of bounds for most vehicles which ply beyond Kolkata.