In standardized conditions of 24 hours clinical hospitalisation the group of men employed as cooking battery staff was examined twice in a 16 years interval. The examined men worked all the time at the same workshops and were exposed to harmful chemical and physical agents. All the subjects underwent routine medical examination, spirometric tests and the questionnaire of Medical Research Council extended to a smoking habit was gathered for each of men. After 16 years occupational exposition an incidence of chronic bronchitis increased from 6.1 to 24.6%. Also the significant decline of ventilatory parameters was noted. About 80% of examined workers showed greater than expected related to natural process of growing old, decline of ventilatory functions. Non significant differences between smokers and non-smokers were noted.