Chairmanís Air Pollution Seminar Series

Tuesday, August 19, 2003
10:30 a.m. to 12:00 Noon
9500 Telstar Avenue
Annex II, Conference Room 106
El Monte

Operation of an Advanced Mobile Air Monitoring Platform in Los Angeles:
Ultrafine PM and Associated Gaseous Pollutants in Urban Air

Dane Westerdahl

We deployed a highly-instrumented electric Toyota RAV4 for the study of ultrafine particulate matter (UFPM) and associated gaseous air pollutants. This platform was operated for several months on freeways and arterial roads, in industrialized areas, and in residential neighborhoods in Southern California. It was completely self-contained, nimble, and presented no pollution signal to complicate the interpretation of observations. Instruments onboard consisted of Scanning Mobility Particle Sizers, Condensation Particle Counters, an Electrical Aerosol Detector, an Aethalometer for black carbon, PAH, NOx, CO, and CO2 analyzers, temperature and humidity measurement devices, and a PM2.5 nephalometer. Instruments provided real or near-time measurements with high time resolution.

This instrumented platform represented a new tool that allowed us to address important questions about UFPM in community air, including: What are the principal sources of urban UFPM? What happens to freshly emitted particles? How can UFPM best be characterized and what are the potential and real exposures experienced by people on highways and in neighborhoods? Results and experience gained from this study will be presented along with initial interpretations of the nature of UFPM and its associated pollutants with regard to human exposure. It was performed by Research Division staff, in close cooperation with the University of Southern California Aerosol Laboratory, the Southern California Particle Center and Supersite, and with help from the South Coast Air Quality Management District and ARB's Monitoring and Laboratory Division.
Dane Westerdahl is the Health Advisor to the Health and Exposure Assessment Branch of the Research Division. He has 26 years experience at the ARB overseeing health effects research and related air monitoring programs.

for more information on this Seminar please contact Dane Westerdahl at 323-1522 or send email to:


for a complete listing of the ARB Chairman's Series and the related documentation for each one of the series please check this page