TRENDS OF ATMOSPHERIC FINE AND COARSE PARTICULATES IN KUALA-LUMPUR, MALAYSIA (1986-1990)

Daily samples of atmospheric fine particulates (FP; particle less-than-or-equal-to 2.5 mum diameter) and coarse particulates (CP; 2.5-10 mum diameter) were collected by a dichotomous sampler sited at the Universiti Tecknologi Malaysia, Kuala Lumpur. Results are presented form a five year duration monitoring programme carried out from October 1986 to December 1990. These results show that the FP mass concentration is twice the CP concentration and constitutes approximately 70% of the inhalable particulate (IP) matter at the site (IP=FP+CP). The seasonal variations of FP, CP and IP particulate concentrations were consistent throughout the sampling period, with the coefficient of variation of particulate concentration varying between 22% and 122%. A marked seasonal variation in particulate concentration was observed, concentration being highest during dry periods and lowest in the wet periods of the year, with a decrease of 8% to 32% in the particulate mass concentrations compared to the average concentration over the study period. The elevated concentrations of fine particulates observed during local haze episodes suggest that this fraction contributes significantly to the haze phenomenon. The CP concentration showed a declining trend of 41% from 1986 to 1990, but no significant trend for FP was observed at the site. The increasing trend of FP/CP ratio (100% increment over this period) reveals an increasing dominance of fine particulates in the region.