INDOOR OUTDOOR RELATIONSHIP FOR INORGANIC COMPONENTS OF COARSE AND FINE PARTICLES

The ionic profiles of PM10 and PM2.5 aerosol samples were evaluated in side and outside of three residences in the Taipei area. The mean indo or and outdoor PM10 concentrations were 73 and 101 n mole m-3 for Na+, 26 and 30 n mole m-3 for K+, 150 and 150 n mole m-3 for NH4+,30 and 6 0 n mole m-3 for Cl-, 108 and 117 n mole m-3 for SO42-, and 88 and 112 n mole m-3 for NO3-. For PM2.5 samples, the mean indoor and outdoor l evels were 41 and 35 n mole m-3 for Na+, 21 and 21 n mole m-3 for K+, 129 and 117 n mole m-3 for NH4+, 7.5 and 12 n mole m-3 for Cl-, 80 and 83 n mole m-3 for SO42-, and 55 and 43 n mole m-3 for NO3-. On averag e, the sum of the six analyzed ions constituted 22%-26% and 20%-30% of the total mass concentration from the PM10 and PM2.5 samples, respect ively. Regarding the Indoor/Outdoor (I/O) ratios, the median values of the measured ions were observed to be smaller than 1. Concerning acid precipitation, the major portion of the acid present in Taipei is ass ociated more with SO42- than with NO3-, and aerosol sulfate are neutra lized by atmospheric ammonia to form (NH4)2SO4.