Figure 3 shows comparison of simulated and observed daily average PM10 concentrations for winter and rainy season episodes. The comparison shows that simulated values are generally in good agreement with the observation of both time variations and level of PM10 concentrations. Furthermore, simulated hourly average PM10 concentrations are within a factor of two of the observations more than 80% for every episode. This performance is in the acceptable range of criteria applied in other studies (Kumar et al., 2006)