KOLKATA: The state government has banned 15-year-old commercial vehicles, replaced petrol-drive two-stroke autos with four-stroke LPG ones and put into effect Bharat Stage-IV emission standard. But all measures have failed to yield result as air pollution shoots up at night when overloaded goods vehicles emit toxic fumes unchecked.
According to a senior Pollution Control Board (PCB) officer, emission by overloaded vehicles at night is defeating the purpose of implementing stringent norms during the day. There has been no control over emission standard of thousands of goods vehicles that enter the city after 9pm and ply till early morning next day, he conceded.
In fact, the respirable particulate matter (RPM) and nitrogen dioxide (NO2) level at night have shot up alarmingly, stated PCB in its report to the high court. Environment crusader Subhas Dutta said: "The transport department and the pollution board have admitted the problem. I had submitted some suggestions to curb this menace. But no action has been taken till date."
As many as 50,000 overloaded and polluting goods vehicles enter the city every night. According to a government report, only 1,091 tests were carried out over the last one year. "This effectively means that not even three vehicles were checked in a day. At least 200 tests should be carried out every night. The Supreme Court had issued specific directions in 2005 to check the movement of overloaded, polluting goods vehicles," said Dutta, who was the first to start a legal battle to stop night pollution.
The SC had directed the government to put up checkposts along national highways to measure the weight of goods vehicles and their emissions. If a vehicle was found to be overloaded, the additional load was to be dumped on the spot. Nearly all states have followed these directions, except Bengal.
An analysis of air quality data of 17 manual stations in Kolkata revealed that except monsoon months, the trend of RPM levels is increasing from day to night time over the last four years. Comparison of daily average concentration of RPM level with that of night shows that from September to March every year, the RPM concentration at nights is more than that of during the day.
Nitrogen di-oxide is a typical air pollutant directly related to emissions from fossil fuel burning, said a PCB official. Nitrogen di-oxide, for Kolkata, has been on the higher side compare to the national standard.
