Studies of Populations Exposed to Occupational Sources of Radiation

在83名飞行员（考虑到他们的宇宙辐射暴露水平增加）和51名飞行经验最少的大学教员中，进行了一项生物剂量学研究，通过评估宇宙辐射暴露和荧光原位杂交的染色体畸变频率来确定染色体畸变频率是否存在差异。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发起了一项全国性的队列研究，对1926-1980年间获得认证的146022名美国放射技师进行了癌症发病率和死亡率的研究。队列中73%为女性。从工作历史数据（收集于1983-89年、1994-98年、2003-2005年，并从2012年开始）以及与死亡信息的追踪和匹配中，我们发现在1950年之前首次工作的技术人员中，乳腺癌、慢性淋巴细胞白血病以外的白血病、皮肤基底细胞癌、黑色素瘤和循环系统疾病的发病率显著增加，并且在1960年之前首次工作的技术人员中甲状腺癌的发病率增加。第一次全面的历史职业剂量重建的高反应率和发展为研究职业性长期低至中等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，这是妇女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。俄罗斯核工作人员的癌症死亡率目前正在对26 000名马亚克核设施工作人员进行研究，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。对孕妇在Mayak设施工作期间宫内辐射照射所导致的癌症死亡率进行的剂量反应分析没有提供任何影响的证据。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。病例对照比为1:5，这一数量的病例提供了足够的能力来检验辐射与白血病风险之间存在关联的假设。如果先前在乌克兰切尔诺贝利清理者中观察到的CLL增加的模式得到证实，该研究还应具有足够的能力来检验这种风险与原子弹幸存者研究中看到的风险不同的假设。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）的科学家以及纽约哥伦比亚大学的科学家和顾问（通过与NCI的合同）共同进行的。这项研究的实地工作已经完成。一篇论文已经发表，报告了慢性淋巴细胞白血病和其他类型白血病的风险显著增加。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与会者和其他专家的反馈意见完善这一模块，并对新的核医学模块进行广泛的试点测试。USRT队列中不同部位紫外线和癌症的研究本项目旨在促进紫外线/维生素D在几种癌症中的作用的研究。我们最近完成了对USRT亚群的紫外线和循环25(OH)D的其他决定因素的分析，该分析已在AJE上发表。另一份关于个体在不同季节中25(OH)D追踪情况的分析报告将很快提交给《临床内分泌学》杂志。其他计划的分析包括25(OH)D和端粒长度之间的关系。我们还计划研究特定紫外线波长与各种皮肤和其他癌症之间的关系。波罗的海清理工人的白血病和其他癌症发病率工人接受的平均辐射剂量约为10 cGy。没有明确的证据表明，白血病、甲状腺癌或与辐射相关的癌症部位与普通人群的发病率相比，风险增加。研究发现，咽喉癌、食道癌、中枢神经系统癌和一系列与酒精有关的部位的癌症风险较高。口腔癌、咽喉癌、酒精相关部位和自杀的死亡率都很高。25年的随访表明，在该队列中，癌症发病率和死亡率的非辐射决定因素占主导地位，而不是辐射的直接影响。女性空乘人员的癌症发病率由于工作场所的暴露，包括宇宙辐射和跨越多个时区的昼夜节律紊乱，空乘人员患乳腺癌和其他癌症的风险可能会增加。我们正在调查9631名女性空乘人员患乳腺癌和其他癌症的风险，以及这种风险是否与宇宙辐射剂量有关。

Markers of Cosmic Radiation Exposure Among Flight CrewA biodosimetry study study was conducted to determine if there were differences in the frequency of chromosome aberrations by assess cosmic radiation exposure and frequency of chromosome aberrations by fluorescence in situ hybridization among 83 pilots (given their increased levels of cosmic radiation exposure) 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 who were certified during 1926-1980. The cohort with 73% females. From work history data (collected 1983-89, 1994-98, 2003-2005, and beginning in 2012) along with tracing and matching with death information, we found significantly elevated incidence risks for breast cancer, leukemias other than chronic lymphocytic leukemia, basal cell carcinoma of the skin, melanoma and circulatory diseases among technologists first working before 1950, and a suggested increase in thyroid cancer in those first working before 1960. The , and very high response rates and development of the first comprehensive historical occupational dose reconstruction 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. 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 provide no evidence of an effect. 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. With a case-control ratio of 1:5, this number of cases provides 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 pattern of CLL increases observed in the Chornobyl liquidators from Ukraine 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 andconsultants from Columbia University, New York (through a contract with NCI). The field work for the study has been completed. A paper has been published, reporting a significant increase risk of both chronic lymphocytic leukemia and other types of leukemia. 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 additional feedback from focus group attendees and other experts, and to perform extensive pilot testing of the new nuclear medicine module. Studies of UV and cancer at various sites in the USRT cohort This project is designed to facilitate study of the role of UV/ vitamin D in relation to several cancers. We recently completed an analysis in a USRT subpopulation of the UV and other determinants of circulating 25(OH)D, which is in press in AJE. An additional analysis of how well 25(OH)D tracks in individuals across seasons will soon be submitted to J Clin Endocrinology. Other analysis planned involve the relationship between 25(OH)D and telomere length. We also plan to examine the relationship between specific UV wavelengths and various skin and other cancers. Leukemia and Other Cancer Incidence in Baltic Clean-up Workers Workers received an average radiation dose of approximately 10 cGy. No clear evidence of increased risk was seen for leukemia, thyroid cancer or radiation-related cancer sites combined relative to incidence in the general population. An elevated risk was found for cancers of the pharynx, esophagus, central nervous system and a broad category of alcohol-related sites. Excess mortality was observed for cancer of the mouth and pharynx, alcohol-related sites taken together,and suicide. Twenty-five years of follow-up suggest that non-radiation determinants of cancer incidence and mortality predominate over direct effects of radiation in this cohort.Incidence of Cancers in Female Flight AttendantsFlight attendants may be at increased risk of breast and other cancers due to work-place exposures including cosmic radiation and circadian rhythm disruption from traveling across multiple time zones. We are investigating the risk of breast and other cancers in 9,631 female flight attendants and whether the risk is cosmic radiation dose-related.