Friday, October 16, 2009

Auto-free roads leave air cleaner

Auto-free roads leave air cleaner
S Lalitha , Oct 14, Bangalore:

Absence of autos on streets of Bangalore, on Monday, due to the strike called by auto drivers’ unions, led to a marked reduction of pollutants in the air. Rains in the evening, in turn, added to the cleansing of air.

To assess the impact caused by vanishing of nearly 80,000 three-wheelers, the Karnataka State Pollution Control Board (KSPCB) monitored the status of ambient (or atmospheric) quality, at two areas in the City, on the day of auto strike and the day before the strike.

Continuous Ambient Air Quality Monitoring Station (CAAQMS) in the City railway station and one at Saneguruvanahalli (S G Halli) collected data on the air quality for upto 4 kms from the location of the monitoring stations.

24-hour period
Data was compared for a 24-hour period from 6 am of October 12 (when the strike commenced) upto 6 am of October 13. This was juxtaposed with data recorded for a 24-hour period from 6 am of October 10.

Majestic area has the most dense auto traffic, at anytime of day, due to the presence of the railway station and KSRTC bus stand. Roughly between 30% to 40% of the City’s autos ply here. This area has reported a steep reduction in oxides of Nitrogen, upto 58.8%, on Monday, said Member Secretary, KSPCB, M S Goudar.

“This is the main pollutant released by LPG used in autos,” he said. From 251.54 micrograms per cubic meter reported during the previous day, it dipped to just 103.49 micrograms per cubic meter on the day of the strike. Nitrogen dioxide causes irritation of nose and throat and increases susceptibility to respiratory infections, he added. By contrast, S G Halli, reported just a mere 8.9% reduction in oxides of Nitrogen.
A clear reduction in levels of Sulpur di oxide (SO2) and Respiratory Particulate Matter (RSPM) too were reported in both areas. While oxides of Carbon reduced by 33.3% at Majestic, there was a 19.4% increase recorded in its levels at S G Halli, data revealed. “This increase could be attributed to increase in usage of two-wheelers in the area,” Goudar said.

Health impact
Exposure to SO2 aggravates lung diseases, especially bronchitis, causes wheezing, shortness of breath and coughing. Long-term exposure to this pollutant and particulate matter leads to higher rates of respiratory illness.

Carbon monoxide enters bloodstream through lungs and forms carboxyhaemoglobin, a compound that inhibit’s blood’s capacity to carry oxygen to blood and tissues.
“It must be remembered that rainfall always reduces pollution level in the air. Downpour has also contributed towards the dipping of pollutants level,” he added. Welcoming the study of KSPCB as “a positive step towards making the environment greener,” Transport Commissioner Bhaskar Rao said the reason for the release of such pollutants by autos was the presence of two-stroke ones.

“Most of the autos in City, roughly 65,000, are two-stroke ones and incomplete combustion in them causes pollution. Our objective is to phase them out and replace them with four-stroke ones,” said Goudar, Member Secretary KSPCB.


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