Comparison between acid aerosol exposure of asthmatic schoolchildren and traffic density in metropolitan Taipei

Our study subjects included 34 asthmatic schoolchildren from three levels of traffic density areas in Taipei city. The acid aerosol exposure concentrations of these subjects in campus and their homes were determinate to analyze the exposure source. School campus and home acid aerosols were sampled using Chemcomb℘ model 3500 and ChemPass® model 3400, respectively. All samples were analyzed by using ion chromatography. The higher sulfur-containing aerosols in schoolchildren's campus were observed, but the schoolchildren's homes were found the higher Cl-containing compounds (Fig. 1). Obviously, acid aerosol composition was quite different in campus and in homes. The exposure data of each student, which was calculated by time/activity pattern analysis, indicated a positive relationship between acid aerosol concentrations and traffic density. These results also support that use of personal activity diaries along with schoolchildren's homes and campus measurements to predict actual schoolchildren's exposure to air pollution are warranted.