Elemental profiles of indoor and outdoor particulate matter less than 10 μm (PM10) and 2.5 μm (PM2.5) in Taipei

Abstract The total (TSP), PM10, and PM2.5 aerosol samples have been collected simultaneously in indoor and outdoor air of three residences in the Taipei area. The samples were analyzed by X-ray fluorescence for up to 20 elements (Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, and Pb). The dominant elements in TSP, PM10, and PM2.5 particulate matter were observed to be aluminum, silicon, sulfur, chloride, potassium, calcium, titanium, iron, zinc, and lead. In addition, their individual concentrations were even higher than 1 μg/m 3 , in some cases. For most of the measured elements, the Indoor/Outdoor ratios were found to be smaller than 1, which suggested most of indoor particles appeared to be mainly influenced by the infiltration of outdoor air. Moreover, the observed high enrichment factors indicated that man-made sources are a great contributor to indoor air quality.