Occupational dust exposure and cancer mortality--results of a prospective cohort study

Over the period 1950-60, occupational and smoking histories were collected in the course of the preventive medical examinations of 247,064 workers in Vienna. Of these, 1630 male workers aged greater than or equal to 40 were selected because of their occupational exposure to silica and 'inert' dusts, and were matched for age, time at which observation was begun, and smoking with 1630 subjects from the same source but without such exposure. Follow-up of 99.8% of the members of these two cohorts resulted in 60,237 person-years of observation, while identification of the underlying cause of death for 98.8% of them (by autopsy in greater than 50%) up to the end of 1985 showed a significantly higher mortality from lung cancer in dust-exposed subjects (179 cases) as compared with those not so exposed (141 cases) and with the local population (standardized mortality ratio (SMR 169). This excess lung cancer mortality was found in all subgroups (SMR in foundries 164, other metal industries 133, ceramics and glass 237, stone and construction 294), consistent with the hypothesis that long-term heavy occupational exposure to silica and 'inert' dusts promotes lung cancer. The only other cancer site for which the number of cases was significantly greater in those exposed to dust was the stomach (SMR 166).