A Statistical Survey of Malignant Neoplasm Mortality among Atomic Bomb Survivors in Nagasaki

A statistical survey was conducted on 1,347 reported deaths due to malignant neoplasm in Nagasaki City, among whom 629 cases had history of exposure to the atomic bomb explosion on August 9, 1945. The following findings were resulted from this survey. 1. Neoplasm of the digestive organs has the highest incidence of 72.8 per cent in male and 53.8 per cent in female, followed by that of the respiratory system in male and the reproductive system in female. Neoplasm of the lymphatic and hematopoietic system, which is supposed to be related closely to radiation, is 6.2 per cent in male and 4.1 per cent in female, significantly higher than the average incidence in Japan. 2. Higher neoplastic mortality was found in the younger generation as compared to the national rate, and majority of the cases in this age group belong to categories No. 200 to 205, namely malignant neoplasm of the lymphatic and hematopoietic system. If one exclude this 200-205 disease group, there is found no difference of incidence between the local, or the exposed, and the national neoplastic mortality in age distribution. 3. Control study of neoplastic mortality in Nagasaki Prefecture disclosed the incidence lower than the rate either of the nation or of the exposed, while the last two are almost identical