Chlorine Dioxide Reduces School Absentism

Effect of chlorine dioxide gas of extremely low concentration on absenteeism of schoolchildren

Gas-generating devices of chlorine dioxide (ClO2) are used as deodorant of rooms. We happened to use a commercial tabletop deodorant canister that releases extremely low-concentration ClO2 gas in a school classroom as deodorant. We found retrospectively and unexpectedly that during a period of 38 consecutive school days the rate of school children absent from the school was markedly lower (1.5%) in a classroom where the ClO  device was placed than that (4.0%) in a classroom where it was not placed. The percentages of absenteeism between these classrooms (1.5% vs. 4.0%) were significantly (p < 0.00001) different. The predominant causes of absenteeism during the period were common cold and influenza. Judging from the known viricidal activity of ClO2 , our unexpected finding in the school classrooms strongly suggests the usefulness of extremely low-concentration ClO2 gas to prevent respiratory viral diseases in semi-closed areas, such as theaters, hospitals and aircraft, without necessitating evacuation.