ARB Research Seminar

This page updated July 26, 2013

Exposure to Diesel Exhaust Particulate Matter in Vehicles: Implications for Exposure Assessment and Control Priorities

Scott Fruin, Air Resources Board

February 04, 2003
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA

Press Release: 1. 2. 3.
Research Project


On a per-time basis, time spent in vehicles is the most important route of exposure to air pollutants for most people. Air pollution concentrations inside vehicles are often an order of magnitude higher than ambient air, and Californians average over an hour and a half per day in vehicles. This talk describes results of a recent in-vehicle diesel exhaust particulate matter (DPM) exposure assessment performed for the first time for California driving, and its implications for overall exposure. The assessment found that the six percent of our day we spend in vehicles causes about one-third of our total DPM exposures. This high relative importance of in-vehicle exposures means on-road diesel emissions contribute three times more exposure on an equal mass basis than off-road diesel emissions.

Speaker Biography

Scott Fruin is a member of the Health and Exposure Assessment Branch of the Research Division at the Air Resources Board. He is also a Doctoral Candidate in the UCLA's Environmental Science and Engineering Program in the School of Public Health, where he is a Chancellor's Fellow and Switzer Environmental Fellow. This seminar describes his thesis work conducting an exposure assessment for DPM, building on the previous assessment conducted for the decision to declare DPM a Toxic Air Contaminant. He obtained his bachelor's and master's degrees in mechanical engineering at the University of Minnesota, doing his master's research at the Particle Technology Laboratory.

For a complete listing of the ARB Research Seminars and the related documentation
for the seminars please view the Main Seminars web page