Current
Home > Quantum Life and Medical Science Directorate > Dept. of Radiation Regulatory Science Research

Quantum Life and Medical Science Directorate

Dept. of Radiation Regulatory Science Research

Update:2021年4月1日更新
Display printing page

 QST is one of the Technical Support Organizations of the Nuclear Regulatory Agency in the fields of nuclear emergency and radiation protection. Radiation regulation should be improved to be more reasonable and reassuring based on scientific evidence and social consensus. In cooperation with other divisions of QST as well as domestic and international organizations, Department of Radiation Regulatory Science Research conducts the activities below so that the results of radiological sciences are quickly applied for the establishment of safety of public.

  • Collecting research information on the radiological sciences and medical and occupational exposure data
  • Providing the research results and data from national surveys of Japan to international organizations in the field of radiological sciences
  • Providing accurate information regarding radiation exposure in response to social needs
  • Leading the research necessary for assessing the effects of radiation and reducing the risk after exposure
  • Improving the techniques for effective decorporation after nuclear accident and subsequent radiation injury treatment
  • Understanding molecular mechanisms of radiation damages to elucidate and control biological responses

Research Theme

Japan's functions as a hub in the international information network on radiological protection

Every year, numerous research reports are published concerning the sources and effects of radiation, and protection from it. The results of this kind of radiation research and approaches to radiological protection are exchanged as information back and forth between numerous collaborating international agencies and organizations, before they are incorporated into Japanese law and regulations. The Radiation Protection Information Center gather the results of Japanese research into radiological medicine and data concerning exposure, and provides these information to international expert organizations, which helps to raise Japan's presence in international society. At the same time, we investigate international trends in the latest radiological protection, and report it to regulatory authoritiesphoto of Japan's functions as a hub in the international information network on radiological protection1
UNSCEAR

Japan's functions as a hub in the international information network on radiological protection

The response to the TEPCO Fukushima Daiichi reactor disaster has raised concern in society over the effects of radiation. The Radiation Protection Information Center has the role of providing the government, local authorities, citizens, experts, and various other stakeholders with accurate information about the impacts of radiation on people and the environment, and about science-based radiological protection systems. As one element in that work, we are compiling a "nowledge Base of Radiation Effects and Radiological Protection" which is a comprehensive collection of knowledge about current radiation-related regulations, systems for radiation management, international radiological protection, and the like. In the future, we will publish this knowledge base as a web-based system, to promote understanding and foster peace of mind about radiation, and to be of use in the preparation of future standards for radiological protection.

photo of Japan's functions as a hub in the international information network on radiological protection1
photo of Japan's functions as a hub in the international information network on radiological protection2

Quantification of doses and risks in order to identify radiological protection issues and propose solutions

There are some types of radiation exposure that are not subject to control in Japan. They are medical exposure to patients, public exposure to radioactive materials from natural sources, and exposure in non-human organisms. There are individual reasons why each of these is not controlled, and for some of them, the actual state of exposure is unknown. Therefore, we clarify the urgency of each issue and its solutions on the basis of scientific evidence, in the forms of dose estimation and risk estimates, and make proposals to regulatory authorities. Most of these issues are caused by low-dose exposure, and their doses and risk assessments involve some uncertainty. We research health and environmental risks and risk perception, in order to clarify the factors and degrees of uncertainty, and take appropriate action from the perspective of radiological protection.

protection issues and propose solutions

System development and nationwide surveys to ascertain patient exposure doses

The use of medical radiation is trending upwards around the world. The per-capita medical exposure among the Japanese public is high compared to other countries, accounting for a majority of ordinary exposure. Therefore, we are developing a system to automatically collect and database information on radiological diagnosis that is held by medical institutions, and a Web-based system (WAZA-ARI that evaluates the dosage received by organs from CT examinations. The data collected by the system is used to devise radiological protection measures for patients, such as setting guideline values for checking the appropriateness of imaging conditions in radiological examinations. This activity is extended nationwide through the Japan Network for Research and Information on Medical Exposure (J-RIME organized among related scientific associations.

photo of System development and nationwide surveys to ascertain patient exposure doses1

Waza-ari A web-based CT dose calculator-

photo of System development and nationwide surveys to ascertain patient exposure doses2

Studies on internal contamination and decorporation of actinides and radionuclides.

In vivo kinetics, tissue and cellular distribution, and metabolism of internal radionuclides including actinides are stuidied to reduce radiation dose from internal radioactive contamination. The information would be applied for more suitable estimation of the committed effective dose of the radionuclides.  Simultaneously, we investigate advanced biodosimetric technology to quantify the cellular damage by the internal contamination. Based on these data and knowledge of the mechanisms on metabolism, we evaluate internal decorporation effects of various substances, preparation forms for adequate drug-delivery, and the combination with commercial medical drugs quantitatively.

Figure for studies on internal contamination and decorporation of actinides and radionuclides

Research for the treatment of radiation injuries with growth factors

This research project aims at developing the treatments and preventions for radiation injuries following accidental exposure to a high dose of radiation, or adverse reactions such as radiation alopecia and gastrointestinal symptoms after radiation therapies.This project also focuses on elucidating radiation-induced DNA damage repair mechanisms and control of cell survival/death decision, thereby clarifying their roles in radiation injuries. In addition, the functions of growth factors (FGFs) and extracellular matrices (carbohydrates) in the niches of tissue stem cells during tissue regeneration after radiation exposure are studied in order to create the novel bioactive molecules for radioprotections and medications.

photo of Research for the treatment of radiation injuries with growth factors1photo of Research for the treatment of radiation injuries with growth factors2

Researching molecular mechanisms of primary radiation damages through Quantitative Redox Sensing

The challenges of Quantitative Redox Sensing Team are 1) identification and quantification of radiation-induced reactive species, i.e. free radicals and/or reactive oxygen species, caused in aqueous or lipidic environments, 2) evaluation of the primary density of those reactive species, 3) prediction of sequential redox chain-reactions, 4) seeking ways of chemical reactions to trigger biological responses and 5) elucidation of impact of LET on radiation induced biological responses. Goals of our research are to figure out chemical mechanisms of bio-molecular damages by ionizing radiations, and to chemically regulate radio-biological responses.

hoto of Researching molecular mechanisms of primary radiation damages through Quantitative Redox Sensing1photo of Researching molecular mechanisms of primary radiation damages through Quantitative Redox Sensing2

Research Group

  • Risks Analysis Group
  • Regenerative Therapy Research Group
  • Internal Decorporation Research Group
  • Quantitative RedOx Sensing Group