COMPREHENSIVE CHARACTERIZATION OF AEROSOLS IN A SUBTROPICAL URBAN ATMOSPHERE - PARTICLE-SIZE DISTRIBUTION AND CORRELATION WITH GASEOUS-POLLUTANTS

This paper presents results of two years of monitoring and research on urban particulates with a focus on submicrometer particles, conducted as a part of an ongoing program on comprehensive characterization of fine airborne particulates and their effect on environmental and human exposures. A large number of data has been collected by the Air Monit oring and Research Station operating in the centre of the subtropical city of Brisbane. The Station is equipped in instrumentation for measu rements of particle size distributions in submicrometer and supermicro meter ranges in addition to the standard instrumentation for monitorin g of the criteria pollutants (PM10, ozone, sulphur dioxide, nitrogen o xides and carbon monoxide). The focus of this paper is on presenting r esults related to characterization of particle size distribution and c oncentration trends in the study period,correlation between particle c haracteristics measured by different instruments, correlation between particle and gaseous data and preliminary conclusions on source charac teristics and source contribution for the investigated area.The averag e submicrometer particulate concentration in the study period was 7.4 x 10(3) particles cm(-3), and the average number median diameter was 4 0 nm. The best correlated data are those ibr submicrometer particles a nd carbon monoxide and nitrogen oxides, suggesting the same source typ e. The lack of correlation between submicrometer and supermicrometer p article concentration data implies different sources for particles in these two ranges. Particle spectral analysis and correlation with gase ous data, indicate that motor vehicle emissions constitute the main so urce of ultrafine particles in the study area. (C) 1998 Elsevier Scien ce Ltd. All rights reserved.