LARGE PARTICLE-SIZE DISTRIBUTION IN 5 UNITED-STATES CITIES AND THE EFFECT ON A NEW AMBIENT PARTICULATE MATTER STANDARD (PM10)

A mobile aerosol-sampling system was used to determine the large particle ambient aerosol size distribution (up to approximately 100 mu m particle diameter) in five cities across the United States: Birmingham, Alabama; Research Triangle Park, North Carolina; Philadelphia, Pennsylvania; Phoenix, Arizona; and Riverside, California. A mobile wide range aerosol classifier (WRAC) developed at the University of Florida was used. The study shows that any measurement of ambient particulate matter with a size-fractionating inlet sampler will be influenced by the ambient particle size distribution. Mass distribution measurements determined by the WRAC were compared with mass measurements obtained simultaneously using TSP Hi-Vol and 15 mu m cut-size inhalable particulate network samplers. Aerosol size-classification results showed the presence of a large particle mass mode at all sites sampled.