Source of Support: None, Conflict of Interest: None
In a health survey 1776 subjects were followed regularly from 3 urban and a rural area for 2 winters and summers. Though there were significant age-sex differences, the prevalences of major and minor respiratory symptoms were only in significantly higher in winter. These differences were not so large as indicated by differences in weather parameters. The exsmokers behaved worse; for smokers alone winters were worse. The lack of correlation with seasons may be due to the fact that air pollutant levels are not following a seasonal pattern and health symptoms were fluctuating with SO2/SPM levels.