Delhi seems less polluted now,but autos not best way to travel: Study

“We made two trips a day in an autorickshaw,75 times from South Delhi to Connaught Place. During each trip,we measured the actual particle concentration inside the vehicle while moving through the traffic,” he explained.

The study shows that commuters breathe far more harmful particles inside vehicles while travelling,as compared to areas with ambient air concentration,such as Lodhi Gardens. “The particle matter (PM2.5) concentration inside vehicles can be 1.5 times higher thah the surrounding background air,and ultrafine levels are about eight times higher,” Apte explained.

A lot of this,he said,has to do with exposure to sudden peaks in pollutant levels. Using video footage taken while travelling in an autorickshaw,he illustrated how the readings for particulate matter inside the vehicle spike everytime it gets stuck in traffic.

“There is very little data on exposure to air pollution while in traffic,as opposed to ambient air levels. Ambient air monitors,which are now being installed in Delhi,will miss out on a bit of the story. The fact is,there is a very high concentration of pollutants while travelling in open vehicles,and these peak exposures can do major damage,” Apte said.

Pollution levels have improved considerably over the past decade,and the city is no longer enveloped in black smog,admitted CSE executive director Anumita Roychowdhury. However,she cautioned that the authorities must not take this for granted,because pollutants still pose a major risk to people’s health.

“Earlier,pollution used to be measured only in terms of particulate matter. But now we have new substances to deal with,such as nox and ozone. People who access urban roads regularly and those who live close to roads are at a high risk of being affected by vehicular air pollution. According to estimates,about 55 per cent of Delhi’s population lives within 500 metres of such roads and are,therefore,prone to a variety of physical disorders,” she said.