[Effects of occupational factors on the natural course of chronic bronchitis in a prospective observation of the industrial population].

Frequence of occurrence and dynamics of chronic bronchitis symptoms as well as barrier syndrome in the examined men in a plant was connected primarily with tobacco smoking and less with the age. Mean values FEV1 depended on the age of examined workers and the rate of spirometric values decrease increased with the age and was connected with smoking habit. It has been ascertained that there is a direct relationship between air contamination with dusts and fluorides and frequency of occurrence of chronic bronchitis symptoms, maintenance of the symptoms for 5 years and decrease of FEV1 value at that period especially in a group of smokers.