A mortality study of a cohort of slate quarry workers in the German Democratic Republic.

Following reports from other countries indicating an excess risk of lung cancer among silicotics, a historical cohort of workers employed for at least one year at a company in charge of slate extraction and processing during the period 1953-1985 in the German Democratic Republic has been constructed and followed up for mortality from 1970 to 1985. The results of the study show a mortality excess for infectious and respiratory diseases. The overall lung cancer mortality is not in excess but shows a tendency to increase with time since first exposure. A mortality excess from lung cancer is concentrated among workers receiving compensation for silicosis, suggesting a possible carcinogenic risk for individuals suffering from this pathological condition.