AIRBORNE PARTICULATE MATTER CONCENTRATION AT DIFFERENT HEIGHTS IN A RESIDENTIAL BUILDING IN SINGAPORE

摘要

The paper investigates the concentration of particulate matter (PM) at different storey heights in a building located close to a major expressway in Singapore. The particulate matter concentration (PM) is measured using dust monitors at different levels - deck, level 6, level 11 and the bus stop. Particulate matter has been characterized both in terms of particle mass and particle counts at each measuring location. The characterization in terms of particle counts shows that the fine particles comprise over 90% of the suspended particulate matter (PM10). The fraction of fine particles (PM1) gravimetrically out of the suspended particulate matter (PM10) is highest at the bus stop. The PM1 comprises up to 55% of PM10 at the bus stop as compared to the 46% at level 6 and level 11. The void deck of the building has the highest fraction ofgravimetric mass for the particles between 1 and 2.5 microns whereas level 6 has highest fraction ofgravimetric mass for the particles between 2.5 and 10 microns out of the total PM10. The vertical profile of particle distribution shows that the particle concentration first increases attain a maximum value and then decreases for higher level. It is observed that a relatively weak correlation between fine and coarse mode particles is observed at level 6 in comparison to level 11, deck and bus stop.