Double-blind Sham Device-controlled Multi-center Crossover Trial of Chlorine Dioxide Gas on the Protective Effect Against Respiratory Infections

Chlorine dioxide (ClO2), which is used as household deodorant, is a volatile gas that displays very strong oxidative activity. Indeed, the powerful oxidative activity of chlorine dioxide (Ogata, N., Biochemistry 46, 4898-4911, 2007) is responsible for its antimicrobial activity against bacteria (Benarde, M. A., et al. Appl. Mircrobiol. 15, 257-265, 1967), fungi (Morino, H., et al. Yakugaku Zasshi 127, 773-777, 2007) and viruses (Ogata, N. and Shibata, T. J. Gen. Virol. 89, 60-67, 2008). Recently, we found that the rate of absenteeism due to illness in a school was lower in classrooms where a chlorine dioxide gas-generating device was placed than in classrooms with no such device. Based upon this unexpected observation we hypothesize that chlorine dioxide gas, at a concentration low enough not to harm humans, may lower the incidence of respiratory infections by inactivating airborne microorganism within an enclosed space.