Characterization of PM10 and PM2.5 source profiles for fugitive dust in Hong Kong

PM10 and PM2.5 chemical source profiles from Hong Kong were investigated for paved road dust and soil. These profiles are needed for urban-scale speciated emissions inventories and for source apportionment by receptor modeling. Five urban soil and five paved road dust samples were collected, dried and sieved, resuspended in a laboratory chamber, air drawn through PM10 and PM2.5 inlet onto Teflon and quartz filters. The filter samples were submitted for both gravimetric and chemical analyses. Chemical analyses included X-ray fluorescence for elemental composition, ion chromatography for water soluble chloride, nitrate, sulfate, atomic absorption spectrophotometry for water soluble sodium and potassium, automated colorimetric analysis for ammonium and thermal/optical reflectance analysis for carbon species. The PM2.5 constituted 11–30% of the PM10 in all geological samples. Al, Si and organic carbon (OC) are abundant constituents in all paved road dust and soil samples. The chemical abundances of PM2.5 and PM10 for a given source type were similar for most species. In addition, results from resuspended soil (three sets), paved road dust (five sets), aggregate (three sets) and cement (two sets) were obtained from Hong Kong Environmental Protection Department (HKEPD) for comparison as well as mass closure analysis.