Decline in children's pulmonary function during an air pollution episode.

Pulmonary function was measured in 163 primary school children before, during and after an air pollution episode. During the episode, TSP, RSP and SO2 concentrations were each in the range of 200-250 μg/m3, whereas during the baseline measurements, they were generally below 100 μg/m3. During the episode, pulmonary functions were significantly lower by 3-5 percent compared to the baseline measurements. The decline was still observed 16 days after the episode, but not 25 days after the episode. Differences in pulmonary function technician, pulmonary function test appliance and in the prevalence of colds between baseline and follow-up measurement were not able to explain the findings. These results suggest that an air pollution episode of a few days, with 24-hour average TSP, RSP and SO2 concentrations in the range of 200-250 μg/m3, was associated with a decrease in pulmonary function of primary school children.