In-Vehicle Air Pollution Study

This page last reviewed March 15, 2010

The exposures to air pollution we receive while in vehicles is quite high and these levels contribute greatly to overall exposures. For vehicle-related pollutants such as diesel PM, this contribution is quite significant, although we do not frequently measure it.
These high in-vehicle concentrations contribute a lot to a person's overall exposure. On average, Californians spend about 90 minutes per day in vehicles. This is about 6% of our 24-hour day. For a compound with multiple sources like benzene, the in-vehicle fraction of total exposure is 15 to 20%. For pollutants like diesel PM the fraction is 30 to 55%. Finally, the fraction for shorter-lived pollutants such as 1,3-butadiene or ultrafine particles may be even higher.
Therefore, although we spend only about 6% of our day driving, we get up to half of our exposures to vehicle-related pollutants during that time.
This study was conducted using an electric vehicle (AV 4) for the sampling platform base vehicle to prevent "self polluting" of the sampling platform.

In Vehicle Fraction of Total Ultrafine Particle Exposure Chart
ARB Health update presentation This presentation was given to the ARB on December 9th.
Mobile Monitoring Pilot Study This is the pilot study that the In-Vehicle data was collected from

For more information Please contact (john q smith) or by phone at 916-323-1490