National Survey on Ventilation Systems and the Health of Occupants in Japanese Homes

The indoor environmental quality and health of occupants in approximately 5000 dwellings were investigated by questionnaire covering the whole of Japan. The purpose of this survey was to clarify the association between indoor air quality and adverse health effects and to study effective ways of keeping indoor air clean using mechanical ventilation. Questionnaires were distributed to 7812 occupants living in mechanically ventilated houses across 47 Prefectures in Japan in February 2012 of which 5265 occupants replied.