The paper was aimed at establishment of the contribution of work conditions to etiology of chronic bronchitis, asthmatic symptoms and lung ventilation disturbances. The investigation involved 354 men producing superphosphate in the Sulphur Processing Plant in Machów near Tarnborzeg and the control group of 276 workers from the same plant but little exposed to industrial dusts. The analysis of mean FEV1 indices with different smoking habits, respiratory tract symptoms and work environment, was based on so called corrected i.e. standardized mean values, with regard to age and increase based on multiple regression equations. In the workers producing superphosphate much more frequent chronic bronchitis (PNO), asthmatic syndrome (ZA) and lung ventilation disturbances were found. Corrected FEV1 arithmetic means in those with PNO and ZA symptoms were significantly lower in those from superphosphate division than in the control group. In addition, in the superphosphate division a significant linear trend of the proportion of lung ventilation disturbances cases, depending on symptoms category, was found. These results reveal harmful effect of air pollution in work environment upon health status of the exposed workers.