[Smoking habits and their influence on the development of chronic broncho-pulmonary diseases--results of epidemiologic research on bronchitis in the German Democratic Republic].

Systematic studies were performed in 1971 and 1973 to investigate the epidemiology of chronic bronchitis. The scheme comprised random groups of a sum total of 22176 men and 10829 women aged between 35 and 64 from 25 places all over the territory of the GDR. The examination program comprised an interview with a questionnaire, measurement of FVC, FEV1.0, PO2 and RV/TK, examination of bronchial hyperreactivity. Representative statements emerged as to prevalence of smokers and ex-smokers. The mean prevalence of male smokers was 63 p. c., of femal smokers 24 p. c. The prevalence of chronic bronchitis is higher in smokers than in nonsmokers especially in the polluted area. Significant relationship was found between increasing tobacco consumption and prevalence of chronic bronchitis. Intensive smoking is associated with an increase in obstruction and in bronchial hyperreactivity. The study provides the evidence of the additive effects of smoking, air pollution and dust exposure at work.