Purpose: To elucidate the actual status of indoor air pollution at newly built or renovated elementary schools, and to evaluate its effects on health symptoms in the affected children.
Methods: In the classrooms of four newly built or renovated elementary schools in Osaka Prefecture, indoor air levels of formaldehyde and volatile organic compounds (VOC) were measured immediately, 1 month, 3 months, 10 months and 22 months after the completion of the construction work. Also, questionnaire surveys regarding subjective symptoms of sick building syndrome were conducted before and after the renovation on the children who attended classes in the renovated rooms.
Results: In the newly built computer classroom, more formaldehyde was detected one month after the completion of the construction work, when computers and furniture were carried in, than immediately after the completion of the work. Then, during the summer season, even 10 months and 22 months after completion of the new building, formaldehyde above the guideline values was detected. In the renovated common classrooms, the formaldehyde level was the same as that in the classrooms which did not undergo renovation, but VOC levels were higher immediately after the completion of the construction work, and the toluene level was above the guideline value. In 4-story reinforced concrete school buildings, indoor air pollution tended to be higher on the third and the fourth floors than on the first and the second floors. In 3-story school buildings, indoor air pollution tended to be higher on the third floor than on the second floor. The survey of subjective symptoms of the children revealed a tendency toward an increase in the prevalence of sick building syndrome after a renovation. However, the actual number of the children complaining of the symptoms hardly changed. Instead, the number of symptoms for each subject increased, and this increase was significant in 5th and 6th grade boys.
Conclusion: In the some classrooms of newly built or renovated elementary schools, chemical substances above the guideline values may be detected. In such classrooms, more ventilation is required.