Annual report of National Institute of Radiological Sciences of the fiscal year 1981

This institute was established in 1957, and has engaged in the research on the injuries of human bodies by radiation and the medical utilization of radiation, and in the training of engineers for this field. Recently, the peaceful use of atomic energy has advanced, and the research on the safety of environmental radiation has become important. Also the social concern to the medical utilization of radiation has heightened. The works carried out in fiscal 1981 were as follows. As the special research which is carried out on large scale utilizing the all-roundness of the institute, the research on the estimation of the danger of low level radiation to human bodies, the investigation of the exposure to environmental radiation due to nuclear facilities, and the research on the medical utilization of particle accelerators were performed. As the designated research to be promoted urgently, the revaluation of radiation dose in the atomic bombing of Hiroshima and Nagasaki, the research on the refining of cell growth genes and their action, the research on the radiation effect to the in vitro culture system of the initial embryos of mammals, and the examination of the various factors modifying the natural killer cell activity of man were carried out. The summaries of these researches as well as those of ordinary researches are reported. (Kako, I.)