Resumen
This study was conducted to investigate the compositional characteristics of particulate matter (PM) collected both at an urban background site (Elms Road observational site, EROS) and a roadside site (Bristol Road observational site, BROS). PM samples were collected at the receptor sites between March 28 and April 11, 2012. Observed parameters included water-soluble ions (Cl?, NO?3, SO42?, Na+, NH4+, K+, Mg2+, Ca2+) and trace metals (V, Al, Cr, Mn, Fe, Zn, Cu, Sb, Ba, Pb). Results showed higher concentrations of NO?3, NH4+, Al and Fe at BROS than EROS regarding PM2.5; and Cl?, NO?3, Na+, K+ and Fe regarding PM2.5-10, indicating roadside increments. The ionic and metal components of PM2.5 at EROS constituted 44 and 7% of the total measured PM mass, respectively. The proportions of these species were 46 and 8% at BROS. For PM2.5-10, water-soluble ions and trace metal components represented 42 and 12% at EROS, and 56 and 11% at BROS.