Low-Dose Exposure to Ionizing Radiation in Adulthood and Subsequent Cancer

摘要 与大多数致癌物不同的是，大多数致癌物一旦被识别就会减少或消除，电离辐射暴露 过去 3 年来，美国的人口数量有所增加。典型美国人的年辐射剂量增加了一倍 在此期间，主要是由于诊断性医疗程序的辐射暴露增加，例如 CT检查。此类手术的剂量通常相当低，但可能会随着时间的推移而重复 超过成年后增加。 该项目的目的是加强对重复低剂量相关癌症风险的了解 成年后暴露于电离辐射。最有前途的癌症风险流行病学研究之一 在低剂量电离辐射暴露后，对接受过单独治疗的人进行队列研究 通过个人辐射剂量计监测辐射暴露情况。我们组建了一个国际化的 来自世界上信息最丰富的一些群体的 308,000 名辐射剂量计监测工作人员组成的队列 英国、法国和美国。在这里，我们提出了每个群组的主要更新以及 一套创新的分析，可直接解决与辐射防护和决策相关的问题 关于低剂量率外部电离辐射暴露。具体来说，我们建议评估：1）癌症 特定地点的电离辐射风险； 2）与年龄相关的低剂量电离辐射易感性变化； 3） 自接触以来，老年人患癌症的相对率随时间的推移而持续存在，占 竞争风险； 4) 低剂量电离辐射暴露影响的人口水平估计 癌症风险。拟议的研究可能会对该领域产生持续的影响，并产生重大影响 对国家和国际辐射防护建议的贡献。证据来自 拟议的研究将有助于为成本效益评估提供信息，并了解增加 接触电离辐射对癌症发病率的影响。

ABSTRACT Unlike most carcinogens, which have been reduced or removed once recognized, ionizing radiation exposure has increased in the USA over the last 3 decades. The typical American's annual radiation dose has doubled over that period primarily due to increasing exposure to radiation from diagnostic medical procedures, such as CT exams. The doses from such procedures are typically quite low, but may be repeated over time and increase over adulthood. The aim of this project is to strengthen understanding of cancer risk associated with repeated, low dose exposure to ionizing radiation in adulthood. Among the most promising epidemiological studies of cancer risk following low dose ionizing radiation exposures are cohort studies of people who have been individually monitored for radiation exposure through personal radiation dosimeters. We have assembled an international cohort of 308,000 radiation dosimeter-monitored workers from some of the world's most informative cohorts in the United Kingdom, France, and USA. Here we propose major updates of each these cohorts and an innovative set of analyses to directly address questions relevant to radiation protection and decision making regarding low dose rate external ionizing radiation exposures. Specifically, we propose to assess: 1) cancer site-specific ionizing radiation risks; 2) age-related changes in susceptibility to low dose ionizing radiation; 3) persistence with time since exposure in excess relative rate of cancer among older adults, accounting for competing risks; and, 4) population-level estimates of the impact of low dose ionizing radiation exposures on cancer risk. The proposed study is likely to exert a sustained influence on the field and make a major contribution to national and international radiation protection recommendations. The evidence from the proposed study will help to inform cost-benefit assessments, and understanding of the role of increasing exposures to ionizing radiation on cancer rates.