Responsibility beyond 60 years.

T his year marks the 60th anniversary of the atomic bombings of Hiroshima and Nagasaki that ended World War II. Whatever the historical circumstances at the time, the bombings were tragic experiences for the cities and for the many who sustained severe blast, heat, and radiation injuries. The horrifying consequences prompted efforts to control nuclear arms proliferation, an issue that still remains a top foreign policy priority. The cities have made remarkable recoveries, and the survivors maintain indomitable spirits, allowing themselves to serve as a reference point for modern radiation safety in the world. As the size of this population of survivors grows smaller, we must not lose a sense of responsibility to support them and to investigate and understand the health consequences engendered by these events. This week, the World Health Organization and Nagasaki University hold a joint meeting to review the latest information on radiation-induced effects in the atomic bomb survivors and to consider the implications of this research for international policies. Since the bombings, follow-up investigation of the health of the survivors has continued. States and Japan became equal funding partners, creating the Radiation Effects Research Foundation to continue the study. The main epidemiological investigation of atomic-bomb survivors is the Life Span Study. It is based on a large cohort from a general population of both sexes and all ages, encompassing a wide range of accurately known doses and incorporating accurate recordings of disease incidence and mortality. The original cohort had 120,000 survivors. This included large representative groups of young people, who are the people currently being monitored. At present, about 43% of the Life Span Study cohort is still alive. A major finding is that radiation-associated cancers continue to occur as a small enhancement of the background rates. Through the year 2000, 8% of the deaths from solid cancers in individuals exposed to radiation could be attributed to radiation. Many of these radiation-related cancer deaths were recorded in recent years of monitoring, indicating that as the survivors age and enter the cancer-prevalent period in their lives, significant additional radiation-related deaths can be expected. Radiation-associated deaths from leukemia (46% of all leukemia deaths) peaked within 10 years of the bombings and no longer occur. Noncancer deaths are also showing a small but significant relationship, with radiation exposure making up 1.4% of these deaths. That finding requires explanation of the underlying mechanisms. Genetic effects are being investigated, although …