Facing cold weather, some drivers let their car engine run for a few minutes before driving away, a practice that is harmful to air quality, a recent study by the Environmental Protection Administration (EPA) showed.
Using a device called a Proton Transfer Reaction Mass (PTR-MS) to monitor air quality in an underground parking lot between the peak hours of 8am and 8:20am and 5pm and 5:20pm, the EPA said comparisons of benzene and acrolein densities in the air between peak and off-peak hours showed the average density of the two pollutants was 3.9 times and 3.8 times higher in the afternoon peak hours than off-peak hours.
The study also showed the average density of both -substances was 1.6 times and 2.5 times higher in the morning peak hours than during off-peak.
“We think the results may have something to do with the fact that many drivers do not leave immediately after they start their car engine,” said Wu Yueh-chuen (巫月春), a section chief at the EPA’s Environmental Analysis Laboratory. “The underground parking lot may not be equipped with a ventilation system either, which could explain the surge in density.”
Benzene is produced when there is an effusion of diesel or gasoline. Acrolein, for its part, is a volatile organic compound produced when there is incomplete combustion.
Long-term exposure to benzene can lead to leukemia, while acrolein can damage lungs and increase the risk of cancer.