Occurrence of cancer in a small cohort of asbestos-exposed workers

During the construction period of a saltpeter plant from 1928 through 1929, 21 young men of equal age were heavily exposed to asbestos dust for 1 a. During an observation period from 1 January 1943 to 30 June 1980 three cases of lung cancer and two cases of mesothelioma were observed in the cohort. The number of lung cancers to be expected was 0.21. Radiographic changes associated with asbestos exposure were present in 17 of the 18 available chest radiographs.