Study of development and application of a new model for radiation-associated cancer risk by using geographical information of atomic bomb survivors' residence

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K10500
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 58030:Hygiene and public health-related: excluding laboratory approach
• Research Institution: Hiroshima University
• Principal Investigator: Yoshinaga Shinji 広島大学, 原爆放射線医科学研究所, 教授 (50270616)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: がんリスク / 自然放射線 / 原爆被爆者 / 統計モデル

Outline of Final Research Achievements

Based on the database of A-bomb survivors maintained by the Research Institute for Radiation Biology and Medicine, Hiroshima University, the present research was conducted for the purposes of evaluating cancer risk among A-bomb survivors in Hiroshima in relation to residential history, quantifying cancer risk taking into account of residential history, and developing and applying new cancer risk models taking into account natural radiation exposure dose related to residential location.
Although the cancer risk assessment of A-bomb survivors could not be conducted because the extracting and processing of various data including residential histories of the study subjects in the database did not proceed as planned, the major cancer risks due to natural radiation by prefectures were analyzed using statistical models, and a significant association with terrestrial gamma radiation was found for stomach cancer and lung cancer among men.

Free Research Field

放射線疫学

Academic Significance and Societal Importance of the Research Achievements

日本人が居住する地域の大地や宇宙放射線など自然放射線による被ばくは，1年間の平均が約2ミリシーベルトと推定されているが，そのうち外部被ばくについては居住地域によっては数倍以上も変動があることが知られている。本研究は，日本における自然放射線への被ばくによるがんリスクを都道府県別に評価し，一部のがんで有意に上昇する可能性を指摘した。本研究は生態学的研究という限界はあるものの，原爆被爆者や職業被ばく集団の研究においても，自然放射線による被ばくを適切に考慮する必要性を指摘した。