Diurnal Changes in Temperature, and Air Pollutants; and Exacerbation of Asthmatic Symptoms in Children

Abstract

The prevalence of asthma in children has increased. Meteorological factors and air pollutants have been proved to affect the expression of asthma. We conducted a cross-sectional survey exploring the relationship between emergency room (ER) visits for exacerbation of asthma and environmental factors in 2001. A total of 166 children were included. Data on air pollutants and temperature were obtained from Environmental Protection Administration (EPA) and Central Weather Bureau stations respectively. A total of 335 days were divided into two groups of days-days with ER visits because of asthma and days without ER visits. Diurnal change in temperature was the meteorological factor considered. The changes in the different groups were compared by the mean of the Mann-Whitney U-test. The pollutant standards index (PSI) was also grouped and managed by the same principle. The mean value of diurnal changes of temperature on days one week before ER visits was 7.04℃, and that on the other days was 6.68℃ (P=0.039). There was also a significant difference between the PSIs in the group two days before ER visits and the PSIs on the other days. The mean value of PSIs in the group one day before ER visits was 74.14, and 66.97 (P=0.033) on other days. Conclusively, diurnal changes in temperature seem to affect the exacerbation of asthmatic symptoms seven days later. Air pollution affects symptoms two days later.