Cancer patterns in the oil shale area of the Estonian S.S.R.

Age-adjusted incidence rates of stomach, lung, and skin cancer among urban (1967-1972) and rural (1963-1972) population of four administrative districts in the Estonian S.S.R. have been presented. In the Kohtla-Järve district (oil shale area) there was an excess of stomach and lung cancer. High rates of stomach cancer in towns and boroughs of oil shale area may be explained by migration. A great proportion of migrants comes from regions, where incidence rates are 1.6-2.5. times higher than among estonians. Elevated levels of stomach cancer incidence in rural areas of Kohtla-Järva district remained unexplainable. In a retrospective cohort study of 2069 workers who had been exposed to oil shale products from 10 to 20 years an excess of skin cancer in females was found.