... Ohmura, A. and Saito, K. (2005)Measures for reducing the levels of chemical com-pounds in the indoor air of schools—A study of the No. 5 501effect of ventilatio n—. Indoor Environ., 8, 3 5–3 9 (inJapanese).136)Park,J.H.,Byeon, ... (inJapanese).118)Fujitani, Y. and Hirano, S. (2008) Health effects of nanoparticles and nanomaterials (II) Methods for Measurement of Nanoparticles and Their Presencein the Air. Jpn. J. Hyg., 63, 66 3–6 69 (in Japanese).119)Hirose,A .and ... areas complained of narrowness of their houses in the 1960 s. At the time, airtight houses started to be built in urban area, and air pollution due to a lack of fresh air because of the low ventilation...