Korean J Prev Med.  2001 Aug;34(3):253-261.

Short-term Effect of Air Pollution on Respiratory Disease in Seoul : A Case-Crossover Study

• Lee YJ
• Lee JT
• Ju YS
• Shin DC
• Im HJ
• Cho SH

Abstract

OBJECTIVES
To evaluate the hypothesis that air pollution could increase emergency room visits for respiratory diseases, and if so, to quantify the strength of association between those.
METHODS
We compiled daily records of hospital emergency room visits for respiratory diseases in Seoul, from November 1. 1995 to October 31. 1996, by using medical utilization data of unscheduled visits. In addition, air quality and weather data for the same period was collected. And a case-crossover design was applied by adopting conditional logistic regression analysis to determine the relationship between air pollutants and emergency room visits for respiratory diseases. In particular, the control periods were chosen by a bidirectional paired matching technique 7, 14, and 21days before and after the case periods.
RESULTS
Only ozone was associated with the increased number of emergency room visits for respiratory diseases. The relative risk according to a 30ppb increase of ozone concentration (24hr mean, lagged 1day) was 1.91 (95% confidence interval = 1.78-2.05).
CONCLUSION
There was a statistically significant association between the ambient ozone and daily emergency room visits for respiratory diseases.

Keyword

Air pollution; Ozone; Conditional logistic regression; Case-crossover design; Emergency room visit

MeSH Terms

Air Pollutants
Air Pollution*
Emergency Service, Hospital
Logistic Models
Ozone
Seoul*
Weather
Air Pollutants
Ozone