Host: The Japan Radiation Research Society
Co-host: City of Kitakyushu, University of Occupational and Environmental Health, Japan
Research on the health effects of atomic bomb radiation has been conducted at RERF (or its predecessor, ABCC) since 1947. Early studies focused on acute health effects and the potential for heritable genetic effects, but in the 1950s the major prospective cohorts, that have been followed-up to the present, were formed: the Life Span Study (LSS) of mortality and cancer incidence among 120,000 A-bomb survivors and the Adult Health Study (AHS) biennial clinical examination program for a sub-cohort of about 20,000 survivors. Subsequently, cohorts were created of about 3,600 survivors who were in utero at the time of the bombing and 77,000 children of A-bomb survivors (F1 study), including 12,000 F1 individuals receiving clinical examinations. An important feature is that dose reconstructions permit reasonably precise individual A-bomb dose estimates to be assigned to most cohort members. A major finding has been that rates of most major types of cancer are associated with radiation dose, and that the association extends to the low dose range. More recently, we have found associations of radiation dose with cardiovascular and cerebrovascular disease mortality rates as well, but another 20+ years is required to fully characterize these risks. These diseases and other non-cancer effects (e.g., cataract, chronic inflammation), are being more thoroughly documented through clinical examinations and laboratory studies in the AHS. The F1 studies have been negative to date, but that cohort is only about 50 years old on average, so another 30+ years will be required to fully document their morbidity and mortality risk. The longitudinal biological samples that have been collected in the AHS are, and will continue to be, an unparalleled resource for learning about the mechanisms of radiation-induced human disease.
