ELEMENTAL COMPOSITION OF RESIDENTIAL INDOOR PM10 IN THE URBAN ATMOSPHERE OF TAIPEI

Sixty PM10 aerosol samples were collected simultaneously in the indoor and outdoor air of 15 homes in the Taipei urban 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). It was found that 10% of the indoor PM10 samples and 20% of the outdoor PM10 samples exceeded the USEPA 24 h standard for PM10 level (150 mug m-3). In addition, the indoor PM10 concentrations were moderately correlated with the outdoor PM10 concentrations (R2 = 0.51). In regard to elemental concentrations, Al, Si, S, Cl, K, Ca, and Fe were found to be dominant indoors and outdoors, and their arithmetic mean levels were higher than 1 mug m-3. Regarding the indoor/outdoor (I/O) ratios, the median values were observed to be smaller than 1, but nearly 20% of the samples had I/O ratios larger than 1. The highest correlation coefficients between indoor and outdoors levels were for S, Mn, Cu, Zn, Br, and Pb. In addition, it was found that Al was well correlated with Si, K, Ca, Ti, Mn, and Fe. The observed high enrichment factors of indoor and outdoor PM10 samples in the urban atmosphere of Taipei for Cl (2300-3600), S (450-830), Zn (126-200), Br (1600-3000), and Pb (500-950) indicate that sea salt, industrial operations, and automobile are major contributors.