A cross-sectional estimation of lung function was performed on 5,083 subjects of both sexes in 1987. These subjects also completed a self-administered questionnaire (response rate 96.1%). In both sexes FEV1 below the stipulated normal was significantly more common in current smokers than in life-long non-smokers. 23% of the females and 13% of the males reported allergic symptoms. Pollen allergies were experienced by 7% of the females and 5% of the males. 10% of both sexes had experienced asthma or bronchitis as a child. However, only 20% of those who reported childhood asthma or bronchitis still had difficulty in breathing. A low FEV1 was no more common among those who had experienced childhood asthma or bronchitis, or among those who reported allergies, asthma or bronchitis among close relatives, than among those who did not report such potential risk factors. On the other hand, dyspnea was much more common among those who reported the potential risk factors than among those who did not.