OBJECTIVES
The aim of this study was to assess the effect of air pollution on the daily respiratory symptoms of elementary school children in Seoul. METHODS: Using the panel study design, we collected diary data for the children's respiratory symptoms during the 1st day~15th day of April, July, October and December in 2003 among the 2nd and 3rd grade elementary school students. We merged the respiratory symptom data with the ambient air pollution data that was monitored by Ministry of Environment. Using a generalized estimate equation, we evaluated the relationship between the daily symptoms of the subjects and the exposure to air pollution after controlling for various potential confounders. RESULTS: The nitrogen dioxide (NO2) exposure of the current day significantly increased the upper respiratory symptoms (adjusted odds ratio=1.12, 95% CI=1.01-1.24) and the lower respiratory symptoms (adjusted odds ratio=1.18, 95% CI=1.06-1.31) in the elementary school children. The sulfur dioxide (SO2) and carbon monoxide (CO) exposure in the current day was associated with the lower respiratory symptoms (adjusted odds ratio=1.12, 95% CI=1.01-1.25 for SO2; adjusted odds ratio=1.16, 95% CI=1.02-1.32 for CO). CONCLUSIONS: We found that exposure to air pollution affects the daily respiratory symptoms in children. This study suggests that the effect on children's health? due to the short term changes in air pollution levels needs to be considered as an important public health problem.