Keywords: Particulate matter, haze, gaussian plume model, stability, geographic information system
Malaysia has enjoyed one of the least polluted urban environments in Asia. The goal of achieving industrial country status by the year 2020 and the associated rapid economic growth have started to impose costs in terms of industrial pollution and the degradation of urban environment. Depletion of fisheries, air and water pollution, and contamination by industrial wastes become more serious in Malaysia in recent years. Among them, air pollution is the major issue that has been affecting human health, agricultural crops, forest species, and ecosystems. Only a few studies have been conducted on air pollution in Malaysia. Most of them are related to the 1997 haze episode. In most years, the Malaysian air quality was dominated by the occurrence of dense haze episodes. From July to October 1997, Malaysia was badly affected by smoke haze caused by land and forest fires. Previous incidents of severe haze in the country were reported in April 1983 (Chow and Lim, 1983), August 1990 (Cheang, 1991; Sham, 1991), June and October 1991 (Cheang, 1991), and August to October 1994 (Yap, 1995).