Breathing fresh air has been a distant dream for the people of Kolkata for some time now. But things seem to be changing owing to the ban put on 15-year old commercial vehicles and the two-stroke autos. Official records clearly indicate a marked improvement in the air quality of the Kolkata metropolitan area.

In the last three days of August 2009, the Respiratory Particulate Matter (RPM), Suspended Particulate Matter (SPM) and Nitrogen-Di-Oxide (NO2) has recorded relatively lower levels as compared to last year’s figures on the same dates.

The Kolkata Metropolitan Area (KMA) had implemented the High Court ban from August 1, which resulted in the reduction of the concentration of air pollutants.

The level of pollutants in the air are dependent on various factors including the level of emission from point source, meteorological conditions and residence time of the pollutants in the atmosphere.

“We had submitted an affidavit to the High Court on August 19, showing the data analysis of the first 15 days from the time the ban was imposed in 2009 with that of 2008. The data clearly suggests that there has been an improvement in the air quality,” said a senior official of the state Transport department.

Scientists of the West Bengal Pollution Board, however, claimed that an average data on the decline in pollutants will only be possible once the winter sets in. With weather conditions being a strong factor in controlling both the RPM and the NO2 — the two most critical pollutants — the post-monsoon period is the most favourable for the measurement of air quality.

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