FIRST ANALYSIS OF MORTALITY AND OCCUPATIONAL RADIATION EXPOSURE BASEDON THE NATIONAL DOSE REGISTRY OF CANADA

A cohort mortality study of occupational radiation exposure was conduc ted using the records of the National Dose Registry of Canada. The coh ort consisted of 206,620 individuals monitored for radiation exposure between 1951 and 1983 with mortality follow-up through December 31, 19 87. A total of 5,426 deaths were identified by computerized record lin kage with the Canadian Mortality Data Base. The standardized mortality ratio for all causes of death was 0.61 for both sexes combined. Howev er, trends of increasing mortality with cumulative exposure to whole b ody radiation were noted for all causes of death in both males and fem ales. In males, cancer mortality appeared to increase with cumulative exposure to radiation, without any clear relation to specific cancers. Unexplained trends of increasing mortality due to cardiovascular dise ases (males and females) and accidents (males only) were also noted. T he excess relative risk for both sexes, estimated to be 3.0% per 10 mS v (90% confidence interval 1.1-4.8) for all cancers combined, is withi n the range of risk estimates previously reported in the literature.