Abstract
A survey on the particle-size distribution of elements in indoor and outdoor air was performed in 20 homes in 6 Japanese cities. Size distributions of concentrations of 18 elements (Mg, Ti, V, Cr, Mn, Ni, Cu, Zn, Mo, Ag, Sb, Cs, Ba, La, Ce, Pr, Nd, Pb) varied considerably in outdoor and indoor air. The highest contributions for outdoor concentrations of Sb and Pb were from particles smaller than 2.5 μm in diameter, while the concentration of Mg and Ti was the highest from particles larger than 2.5 μm. Indoor concentrations of Zn, Mo, Sb, Pb were predominated by particles smaller than 2.5 μm. The presense of indoor sources of particles or elements was assessed on the basis that BaP could be regarded to be tracer of particles originating from outdoors and penetrating into the indoor air. Most of indoor concentrations of elements in fine particles were almost the same as those outdoors indicating these elements in the indoor particles originated predominantly from outdoors. There are certain indoor sources of the elements in particles larger than 2.5 μm. In contrast to the above mentioned elements, indoor concentrations of 6 elements (Cu, Ag, La, Ce, Pr, Nd) were higher than those of outdoors indicating the presense of their indoor sources. A principle component analysis was conducted for outdoor and indoor elemental concentrations. The results for outdoor concentrations reflected the sampling locality, but the results for indoor concentrations did not.
