Shunichi Yamashita graduated from the Nagasaki University School of Medicine in March 1978 and spent almost three years from July 1984 to March 1987 as the first endocrine research fellow at the Cedars-Sinai Medical Center, Los Angeles. In October 1990, Dr Yamashita became Professor of Molecular Medicine and International Radiation Health at the Atomic Bomb Disease Institute, Nagasaki University School of Medicine. He has been deeply involved in Chernobyl and Semipalatinsk medical aid and research projects for 25 years. Professor Yamashita is the Adviser to the Governor of Fukushima Prefecture on Health Risk Management immediately after the Fukusihma Nuclear Power Plant (NPP) accident. He was dispatched from Nagasaki university to Fukushima for two years after the Fukushima NPP accident. Since April 2013, he has been mainly in Nagasaki University but partly in Fukushima Medical University. He is still in charge of the Fukushima health Management Survey, especially for the thyroid examination as a part-time Vice-President of Fukushima Medical University. Professor yamashita is the Director of the WHO collaborating centre for research on Radiation emergency Medical Preparedness and Response Network, council member of the Science Council of Japan and a member of the Nuclear Disaster Expert Group of the Prime Minister's Office in Japan. He is the former President of the Japan Thyroid Association.
In terms of basic data on radiation and health, the Radiation Effects Research Foundation’s (RERF) long-term survey study of the atomic bomb survivors is the most precise for assessing the consequences of external radiation exposure and cancer death rates. The painfully tragic atomic bombing, as well as other data related to radiation exposures, contributed to the accumulation of scientific knowledge and the creation of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), which reviews the sources and effects of ionizing radiation every few years. In addition, the atomic bomb survivor follow-up studies have formed the bedrock of the International Commission on Radiological Protection’s (ICRP) activities. The ICRP has been working since late 1920-es toward the standards and policy proposals for nuclear safety, such as workplace regulations regarding radiation exposure. The International Atomic Energy Agency (IAEA) formulated its Basic Safety Standards (BSS) based on both the scientific knowledge and policy proposals. Each country, including Japan has devised, on the basis of these recommendations, nuclear safety measures according to their individual circumstances.
However, listening to the discussions and debates on radiation exposure risks since the Fukushima Nuclear Power Plant accident to date, it appears that the international standards, which use the linear no-threshold (LNT) cancer risk model, established from the standpoint of radiation protection do not reflect the real health risks themselves. In particular, the meaning of LNT model and biological effects of low dose radiation exposure have been unsatisfactorily understood. Thus, an inadequate understanding stemming from insufficient knowledge of radiation biology and molecular epidemiology has been exposed.
There is an urgent need in narrowing the gaps between our scientific understandings and public risk perception, which sometimes manifests in fear and anxiety, and even in an anger toward radiation and radioactivity. Here, the current situation and relevant problems of Fukushima will be introduced focusing on the Fukushima Health Management Survey results.