[Acute effects of outdoor air pollution during the winter of 1990-1991 on respiratory health of schoolchildren.]

During the period 15-11-1990 to 1-4-1991 an epidemiologic study was conducted on the relation between air pollution and respiratory health of school children. Pulmonary function was measured by spirometry every second week and by daily peakflow measurements. During the observation period an episode of air pollution occured with slightly elevated concentrations of daily average Black Smoke (up to 120 mug/m3), SO2 and NO2 (up to 100 mug/m3). Statistically significant negative relations were found between Black Smoke, SO2 and the pulmonary function of the children (using spirometry). A positive relation between temperature and air pollution however has been found as well. Due to the high correlation between Black Smoke, SO2 and temperature adjustment for the confounding effects of temperature was impossible. No differences in spirometric response were found between the whole group and a sub-sample of children with chronic respiratory symptoms. In the sub-sample of children with chronic respiratory symptoms, morning peakflow was consistently negative associated with Black Smoke and SO2. This association was independent of temperature but due to small numbers statistically insignificant. Even at air pollution levels below present standards negative associations between air pollution and pulmonary function were found ; some of the observed effects may be partly explained by acute effects of low temperatures.DGM/LE /Blom