Abstract
The purpose of this study is to propose management strategies to lower the level of $PM_{10}$ concentration. First, this study analyzes the characteristics of particle sizes in three different areas, the residential, the roadside, and the industrial areas. Second, it has examined the size of particles which can influence on the increase of $PM_{10}$ concentration level. The distribution of particle size for $PM_{10}$ concentration was not different by regions. The highest portion in the observed $PM_{10}$ is near $0.3{\mu}m$. In addition, both near $2.5{\mu}m$ and near $5.0{\mu}m$ are found higher in portion. The fractions of $PM_{1.0}$ and $PM_{2.5}$ in $PM_{10}$ are 68.2% and 75.8% respectively. The fraction of $PM_{1.0}$ in $PM_{2.5}$ is 89.8%. The particle diameters contributed to the increase of $PM_{10}$ concentration are different by regions. In the residential area, the sizes of near $0.6{\mu}m$ and near $3.3{\mu}m$ particles are found to be the cause for the increase of $PM_{10}$ concentration level. However the particle sizes for the increase of $PM_{10}$ concentration level are $0.8{\mu}m$ and $0.5{\mu}m$ in roadside and industrial area respectively. Therefore, fine particles are found as the key factors to raise $PM_{10}$ concentration level in the two areas, while both fine and coarse particles are in the residential areas. When examined the $PM_{10}$ concentration level change, it was categorized by two different time zones, the high concentration level time and the lower concentration time. In high concentration time, the $PM_{10}$ concentration has increased in the morning in the residential and roadside areas. On the contrary, the level has increased in the evening in the industrial area. In low concentration time, the level of $PM_{10}$ concentration in the roadside area is significantly higher in the morning than the concentration level of other times. There is no significantly different concentration level found in the both residential and industrial areas throughout the day.