2023-08-16 カリフォルニア大学校アーバイン校(UCI)
◆この研究は、30万人以上の労働者を対象に行われ、放射線被ばくとがん死亡率の関連性を調査しています。今回の研究結果は、放射線保護の基準を見直す上で重要な情報となるとされています。
<関連情報>
- https://news.uci.edu/2023/08/16/uc-irvine-led-study-links-low-dose-radiation-to-higher-cancer-risk/
- https://www.bmj.com/content/382/bmj-2022-074520
フランス、英国、米国の労働者における電離放射線低線量被曝後のがん死亡率(INWORKS):コホート研究 Cancer mortality after low dose exposure to ionising radiation in workers in France, the United Kingdom, and the United States (INWORKS): cohort study
David B Richardson,Klervi Leuraud,Dominique Laurier,Michael Gillies,Richard Haylock,Kaitlin Kelly-Reif,Stephen Bertke,Robert D Daniels,Isabelle Thierry-Chef,Monika Moissonnier,Ausrele Kesminiene,Mary K Schubauer-Berigan
The British Medical Journal Published 16 August 2023
DOI:https://doi.org/10.1136/bmj-2022-074520
Abstract
Objective To evaluate the effect of protracted low dose, low dose rate exposure to ionising radiation on the risk of cancer.
Design Multinational cohort study.
Setting Cohorts of workers in the nuclear industry in France, the UK, and the US included in a major update to the International Nuclear Workers Study (INWORKS).
Participants 309 932 workers with individual monitoring data for external exposure to ionising radiation and a total follow-up of 10.7 million person years.
Main outcome measures Estimates of excess relative rate per gray (Gy) of radiation dose for mortality from cancer.
Results The study included 103 553 deaths, of which 28 089 were due to solid cancers. The estimated rate of mortality due to solid cancer increased with cumulative dose by 52% (90% confidence interval 27% to 77%) per Gy, lagged by 10 years. Restricting the analysis to the low cumulative dose range (0-100 mGy) approximately doubled the estimate of association (and increased the width of its confidence interval), as did restricting the analysis to workers hired in the more recent years of operations when estimates of occupational external penetrating radiation dose were recorded more accurately. Exclusion of deaths from lung cancer and pleural cancer had a modest effect on the estimated magnitude of association, providing indirect evidence that the association was not substantially confounded by smoking or occupational exposure to asbestos.
Conclusions This major update to INWORKS provides a direct estimate of the association between protracted low dose exposure to ionising radiation and solid cancer mortality based on some of the world’s most informative cohorts of radiation workers. The summary estimate of excess relative rate solid cancer mortality per Gy is larger than estimates currently informing radiation protection, and some evidence suggests a steeper slope for the dose-response association in the low dose range than over the full dose range. These results can help to strengthen radiation protection, especially for low dose exposures that are of primary interest in contemporary medical, occupational, and environmental settings.
