ABSTRACT
There are few studies about school-environment in relation to pupils' respiratory health, and Korean school-environment has not been characterized. All pupils in 4th grade in 12 selected schools in three urban cities in Korea received a questionnaire (n = 2,453), 96% participated. Gaseous pollutants and ultrafine particles (UFPs) were measured indoors (n = 34) and outdoors (n = 12) during winter, 2004. Indoor dampness at home was investigated by the questionnaire. To evaluate associations between respiratory health and environment, multiple logistic- and multi-level regression models were applied adjusting for potential confounders. The mean age of pupils was 10 yr and 49% were boys. No school had mechanical ventilation and CO2-levels exceeded 1,000 ppm in all except one of the classrooms. The indoor mean concentrations of SO2, NO2, O3 and formaldehyde were 0.6 microg/m3, 19 microg/m3, 8 microg/m3 and 28 microg/m3, respectively. The average level of UFPs was 18,230 pt/cm3 in the classrooms and 16,480 pt/cm3 outdoors. There were positive associations between wheeze and outdoor NO2, and between current asthma and outdoor UFPs. With dampness at home, pupils had more wheeze. In conclusion, outdoor UFPs and even low levels of NO2 may adversely contribute to respiratory health in children. High CO2-levels in classrooms and indoor dampness/mold at home should be reduced.