Studies of Populations Exposed to Occupational Sources of Radiation

利用荧光原位杂交技术对83名飞行员和51名具有最低飞行经验的大学教员进行了生物剂量学研究，以评估宇宙辐射暴露和染色体畸变频率。航空公司飞行员和大学教师的平均易位频率没有差异，但商用飞机飞行年限和易位频率在飞行员中有显著增加的趋势。此外，在调整年龄和飞行年数后，飞行员个人诊断过程中的辐射暴露与易位频率呈正相关。一些饮食和维生素补充剂也与易位频率有关。1982年，REB在146022名美国放射技师中发起了一项全国性的癌症发病率和死亡率队列研究。该队列73%为女性，应答率非常高，为研究职业性长期低至中剂量辐射暴露对乳腺癌和甲状腺癌的影响提供了难得的机会，这是女性辐射致癌的两个最敏感的器官部位。所有其他癌症和非癌症严重疾病的结果也正在评估与长期低至中等剂量照射有关的情况。目前，我们正在扩大这项研究的范围，使其包括一项与辐射照射和循环维生素d水平变化有关的皮肤癌研究。俄罗斯核工人的癌症死亡率。正在对26 000名马亚克核设施工人进行研究，因为他们是长期暴露于高剂量外部辐射和暴露于钚的独特职业群体。改进的剂量测定法和更新的死亡率数据证实了白血病和所有实体癌的外部剂量-反应关系的早期发现。死亡率分析清楚地表明，肺癌、肝癌和骨癌的风险随着钚剂量的增加而增加。目前正在对Mayak设施中产妇就业造成的子宫内辐射照射有关的癌症死亡率进行剂量反应分析。切尔诺贝利白血病研究这是美国-乌克兰联合开展的一项病例对照研究，研究切尔诺贝利事故发生后乌克兰一群清理工人的白血病和其他血液病，研究时间为1986年至2006年，是在切尔诺贝利清理工人中开展的最大的分析研究之一，考虑到事故发生以来的整个观察期、队列规模（约110,000人）和集体剂量。该队列共确诊了137例白血病，包括79例慢性淋巴细胞白血病（CLL）。在1:5的病例对照比下，这一数量的病例将提供足够的力量来检验辐射与白血病风险之间存在关联的假设。如果先前提出的CLL增加模式得到证实，这项研究也应该有足够的能力来验证这样的假设，即风险与原子弹幸存者研究中看到的不同。这项研究是由乌克兰辐射医学研究中心（RCRM）的科学家、美国国家癌症研究所（NCI）的科学家和纽约哥伦比亚大学的科学家和顾问（通过与NCI的合同）进行的。尽管在美国越来越多地使用核医学程序，但对医疗辐射工作人员的暴露模式知之甚少。在美国放射技术人员（USRT）研究中，20%的放射技术人员在其工作历史中曾担任核医学技术人员。2010年11月，环境研究局举行专题小组讨论，由8至10名专家就历史实践提供意见。基于这些发现，以及文献，我们为从事核医学程序的放射技术人员开发了详细的访谈工作模块。我们计划根据焦点小组参与者子集第二次会议的反馈改进该模块，并对新的核医学模块进行广泛的试点测试。生殖系遗传变异和染色体畸变风险在Mayak核武器设施的工人队列中，REB正在阐明生殖系遗传变异对染色体畸变频率的贡献。这些工人受到外部γ和内部钚辐射。USRT队列研究包括一个亚队列中关于终生紫外线辐射暴露、宿主对不良紫外线辐射影响的易感程度以及维生素D暴露的各种决定因素的自我报告数据。我们已经检查并计划继续检查紫外线辐射暴露与各种癌症结果之间的关系，包括可能与癌症风险相关的紫外线辐射暴露的特定模式，检查维生素D的决定因素并评估随时间推移对维生素D状态的跟踪，波罗的海清理工人白血病和其他癌症发病率1998年所有癌症发病率都在两个队列中进行了评估，包括10,000名清理工人，来自爱沙尼亚和拉脱维亚，他们在1986年反应堆事故后被派往切尔诺贝利（乌克兰）。工作人员接受的平均辐射剂量约为10 cGy。与普通人群相比，该组白血病风险发生率没有显著升高。甲状腺癌的发病率增加了，但这似乎是由于，至少部分是由于甲状腺筛查。目前正在扩大这项研究，包括来自立陶宛的7 000名清洁工人，并进行了几年的后续工作。我们对9631名女性空乘人员进行了一项研究，调查她们因暴露在宇宙辐射下而患乳腺癌和其他癌症的风险。该调查收集了6341名在世或代理受访者的问卷。目前正在通过死亡证明或医疗记录确认癌症诊断。

Markers of Cosmic Radiation Exposure Among Flight Crew A biodosimetry study to assess cosmic radiation exposure and frequency of chromosome aberrations by fluorescence in situ hybridization among 83 pilots and 51 university faculty with minimal flying experience. The mean frequency of translocations did not differ between the airline pilots and a comparison group of university faculty, however there was a significant increasing trend among the pilots for number of years flying commercial aircraft and translocation frequency. In addition, radiation exposure from personal diagnostic procedures among the pilots was positively associated with translocation frequencies after adjustment for age and number of years flying. Some diet and vitamin supplements were also associated with translocation frequency. Cancer and Other Mortality Risks in a Cohort of U.S. Radiologic Technologists In 1982, the REB, initiated a nationwide cohort study of all cancer incidence and mortality among 146,022 U. S. radiologic technologists. The cohort with 73% females, and very high response rates offers a rare opportunity to study effects of occupational protracted low- to moderate-dose radiation exposure on breast and thyroid cancer, the two most sensitive organ sites for radiation carcinogenesis in women. All other cancer and non-cancer serious disease outcomes are also being evaluated in relation to protracted low-to-moderate dose exposures. Presently we are expanding the scope of the study to include a study of skin cancer in relation to radiation exposure and variation in levels of circulating vitamin D. Cancer Mortality in Russian Nuclear Workers A cohort of 26,000 Mayak nuclear facility workers is being studied because they comprise a unique occupational group for protracted exposure to external radiation at high doses and for exposure to plutonium. Improved dosimetry and updated mortality data confirm earlier findings of external dose-response relationships for leukemia and for all solid cancers. Mortality analyses have clearly demonstrated that risks for lung cancer, liver cancer and bone cancer increase with increasing dose from plutonium. Dose-response analyses of cancer mortality in relation to in utero radiation exposure from maternal employment at the Mayak facility are underway. Chernobyl Leukemia Study This is a joint US-Ukrainian case-control study of leukemia and other hematological diseases in a cohort of clean-up workers in Ukraine following the Chornobyl accident, carried out from 1986 to 2006 - one of the largest analytical studies performed in Chornobyl liquidators, taking into account the whole period of observation since the accident, cohort size (approximately 110,000) and collective dose. A total of137 cases of leukemia have been ascertained in the cohort, including 79 cases with chronic lymphocytic leukemia (CLL). With a case-control ratio of 1:5, this number of cases would provide adequate power to test the hypothesis of an association between radiation and leukemia risk. The study should also have adequate power to test the hypothesis that the risk is different from that seen in the atomic bomb survivors study if the previously suggested pattern of CLL increases is confirmed. The study is conducted by scientists of the Ukrainian Research Center for Radiation Medicine (RCRM), scientists from the U.S. National Cancer Institute (NCI) and scientists and consultants from Columbia University, New York (through a contract with NCI). Dosimetry for Nuclear Medicine Patients Despite the growing use of nuclear medicine procedures in the United States, very little is known regarding patterns of exposure in medical radiation workers. 20% of radiologic technologists in the U.S. radiologic technologist (USRT) study have reported working as nuclear medicine technologists at some time in their job history. In November 2010, REB held a focus-group discussion in which 8 to 10 experts provided input on historical practices. Based on these findings, as well as the literature, we have developed a detailed interview work module for radiologic technologists working with nuclear medicine procedures. We plan to refine this module based on feedback from a second meeting of a subset of focus group attendees, and to perform extensive pilot testing of the new nuclear medicine module. Germline Genetic Variation and Risk of Chromosome Aberrations among Mayak Nuclear Workers REB is elucidating the contribution of germline genetic variation to the frequency of chromosomal aberrations in a cohort of workers at the Mayak nuclear weapons facility. These workers were exposed to external gamma and internal plutonium radiation. Studies of UV and cancer at various sites in the USRT cohort The USRT cohort study includes self-reported data on lifetime UV radiation exposure, host susceptibility to adverse UV radiation effects, as well as various determinants of vitamin D exposure over time in a sub-cohort. We have examined and plan to continue to examine the association between UV radiation exposure and various cancer outcomes, including the particular patterns of UV radiation exposure that may relate to cancer risk, to examine the determinants of vitamin D and to assess tracking of vitamin D status over time Leukemia and Other Cancer Incidence in Baltic Clean-up Workers All cancer incidence through 1998 was evaluated in two cohorts, comprising 10,000 clean-up workers, from Estonia and Latvia, who were sent to Chornobyl (Ukraine) following the reactor accident in 1986. Workers received an average radiation dose of approximately 10 cGy. Leukemia risk incidence was not significantly elevated in this group compared to the general population. Thyroid cancer incidence was increased, but this appeared to have been due, at least in part, to thyroid screening. The study is being extended to include a cohort of 7,000 clean-up workers from Lithuania and additional years of follow-up. Incidence of Cancers in Female Flight Attendants We are investigating the risk of breast cancer and incidence of other cancers in a study of 9,631 female flight attendants due to cosmic radiation exposure. Surveys from living or proxy respondents have been collected from 6,341 female flight attendants. Confirmation of cancer diagnoses from death certificates or medical records is ongoing.