Abstract
In this study, the variations of indoor-originated NO and NO_2 concentration in the test rooms were surveyed in detail with a chemiluminescent autoanalyzer. At first, some confusing factors on the sink rate of indoor NO_2 were investigated. In the second place, the fate of NO_2 consumed through the rapid decay in higher relative humidity was discussed. The experimental results are as follows: (1) Lighting such as natural light without direct sunbeam or fluorescent lamp, and small variation of air composition don't have any effect. Forced air mixing and repeated exposition to NO_2 of the interior material have little effect; such physical conditions may take effect where the surface reaction is outstanding. A large difference in the air volume of rooms seemed to bring about a small change in the sink rate of NO_2. Since ordinary variations of actual air volume of living rooms are not so large, such an influence may be negligible. (2) A certain part of NO_2 has been proved to be converted to NO through the decay process described above.
