Respiratory health among Korean pupils in relation to home, school and outdoor environment.

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 CO(2)-levels exceeded 1,000 ppm in all except one of the classrooms. The indoor mean concentrations of SO(2), NO(2), O(3) and formaldehyde were 0.6 µg/m(3), 19 µg/m(3), 8 µg/m(3) and 28 µg/m(3), respectively. The average level of UFPs was 18,230 pt/cm(3) in the classrooms and 16,480 pt/cm(3) outdoors. There were positive associations between wheeze and outdoor NO(2), and between current asthma and outdoor UFPs. With dampness at home, pupils had more wheeze. In conclusion, outdoor UFPs and even low levels of NO(2) may adversely contribute to respiratory health in children. High CO(2)-levels in classrooms and indoor dampness/mold at home should be reduced.