著者
工藤 伸一 石田 淳一 吉本 恵子 水野 正一 大島 澄男 古田 裕繁 笠置 文善
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.51, no.1, pp.12-18, 2016 (Released:2016-07-06)
参考文献数
16
被引用文献数
5

Radiation Effects Association has carried out radiation epidemiological study for nuclear industry workers during 1990-2010. We assembled a cohort of 204,103 workers. The average cumulative dose was 13.8 mSv (median 1.0 mSv, interquartile range (IQR) 0.0-10.7 mSv) and the average follow-up period was 14.2 year. The present report has not concluded that low-dose radiation increases cancer mortality based on the follow-up data through 2010. One reason is that analyses among 75,442 respondents― the average cumulative dose was 25.8 mSv (median 6.3 mSv, IQR 0.2-28.0 mSv) and the average follow-up period was 8.3 year―to the lifestyle surveys revealed the decrease of the ERR after adjusting for smoking habits or educational year, suggesting that confounder has a large effect on the association between radiation exposure and mortalities in the cohort. Another reason is that in analyses on all cohort members, no significant ERR was observed in all death, and leukemia excluding chronic lymphoid leukemia. Significant ERR was seen in all cancers excluding leukemia, but this significance of the ERR might be affected by confounder such as smoking, because the significance of the ERR in all cancers excluding leukemia originates in the significance of the ERR in lung cancer.
著者
工藤 伸一 石田 淳一 吉本 恵子 古田 裕繁 笠置 文善
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.52, no.4, pp.265-274, 2017 (Released:2018-02-24)
参考文献数
33
被引用文献数
1

Although many radiation epidemiological studies have been carried out, there is still uncertainty about the health effects of low dose and low dose-rate radiation in humans. One reason for this uncertainty is that the risk of radiation itself may be too small to detect. Another possible reason is that the main components of cohorts or statistical method vary in each study. Comparing the Excess Relative Risks (ERRs) with other studies is often one approach; however, few studies have denoted the validity of comparing ERRs. To verify the differences in study methods, we summarized them and the results of radiation epidemiological studies to date. Some of these studies targeted high background residents or patients who received CT scans. In the present work, we focused on cohort studies among nuclear industry workers because they assured more accurate dose measurements and had no possibility of reverse causation (i.e., patients who received CT scans had worse health conditions, which prompted the need for the scans). In addition, we limited the studies to those that summarize derived excess relative risks of mortality based on a linear model.
著者
工藤 伸一 西出 朱美 吉本 恵子 古田 裕繁 三枝 新
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.54, no.1, pp.29-39, 2019-04-18 (Released:2019-09-03)
参考文献数
30

In August 2018, the latest analysis of the UK National Registry for Radiation Workers (NRRW 3rd update) has been published. The NRRW studies have been published almost every ten years since the first analysis (1992). The series of NRRW aimed to analyse cancer risk from low dose occupational radiation exposure. This latest analysis is the study using third analysis data and an additional ten years of follow-up information, but did not include additionally dosimetry information. As the set of ten years lag period, only the risks of cancer were analysed, but excluding leukaemia risks owing to its lag period as two years. The same statistical methods were used in the series of NRRW study. This review provides an outline and summary of the key points of NRRW 3rd update. We denote introduction in chapter 1, summary in chapter 2, comparison with previous studies and other studies in chapter 3, discussion about results in chapter 4, meaning and limitation in chapter 5 and conclusion in chapter 6.