Long-term health consequences of atomic bomb radiation: RERF Life Span Study

Abstract

Abstract. To determine the possible late health effects of atomic-bomb radiation, Radiation Effects Research Foundation (RERF) has been conducting mortality follow-up on a fixed cohort of 120,000 members (Life Span Study cohort or LSS cohort) since 1950. Through record linkage with local cancer registries in Hiroshima and Nagasaki, RERF has also been conducting cancer incidence studies of atomic bomb survivors since 1958. The central finding of the study is an increase in cancer risk. Besides the increase in leukemia risk, increase in risks of solid cancers such as cancers of the breast, lung and colon have also been demonstrated. Radiation-induced leukemia occurred 2 to 3 years after exposure, reached its peak within 6 to 8 years after the bombing, and has since declined steadily. However, radiation-related solid cancer began to appear at later years and the risk still remains to be present, even today. An increase of solid cancer risk appears to be larger for those exposed as children than those exposed as adults. However, since a majority of those exposed as children are still alive and risk estimates for them are uncertain at this stage, it is essential to continue their follow-up. Recently, the LSS also demonstrates an excess risk of death from non-cancer diseases, largely from cardiovascular, digestive and respiratory diseases. Further investigation is of absolute necessity in order to determine whether or not the excess was caused by atomic bomb radiation.