The complexity of air pollution problems is associated with emission, dispersion, transformation, and removal of pollutants from the atmosphere and is always a challenge in developing effective air quality management. Dispersion modeling is a common tool used to analyze past and current pollution situations and to project future pollution under various emission and meteorology scenarios (details in Chapters 5 and 6). Application of relevant dispersion models is particularly required to study secondary pollutants, which are formed in the atmosphere in a series of complex chemical reactions, such as ozone and secondary particles. These air quality dispersion models are widely available (Kim Oanh and Permadi, 2009; Russell and Dennis, 2000), but they require detailed input data of source emission and meteorology. Lack of suitable emission data with necessary temporal (hourly) and gridded spatial distributions is the common issue in many areas in Asia and therefore presents an obstacle for dispersion modeling.