Studies of Populations Exposed to Occupational Radiation

美国放射技术人员队列中的癌症和其他死亡风险 1982年，放射流行病学分支（REB）与明尼苏达大学合作，在146,022名美国人中开展了一项全国范围的癌症发病率和死亡率队列研究。S.放射技术人员。该队列中73%为女性，这提供了一个难得的机会来研究长期低剂量至中等剂量辐射暴露对乳腺癌和甲状腺癌的影响，这是女性辐射致癌最敏感的两个器官部位。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暴露的关系。2001年以来的主要研究结果包括：1950年以前，随着工作年限的增加，乳腺癌的死亡风险显著增加; 1950年以前，随着工作年限的增加，脑血管病的死亡风险显著增加;与SEER相比，发现乳腺癌（女性）、甲状腺癌和黑色素瘤的发病风险显著升高，并对无应答进行了调整。内部队列分析显示，与1940年以前工作相关的乳腺癌发病风险显著升高，与1950年以前工作相关的黑色素瘤和非黑色素瘤皮肤癌发病风险显著升高，与1950年以前工作>5年相关的非慢性淋巴细胞白血病发病风险适度升高，以及与1960年以前工作相关的甲状腺癌发病风险升高。而与肺癌没有关联。ZBRK 1和BRIP 1基因的突变分析显示，这些基因的突变不太可能占遗传性乳腺癌的很大比例;一级亲属中乳腺癌的亲属队列分析发现，与先证者的HER 2变异状态相关的风险无显著升高，与XRCC 1194和BRIP 1919变异相关的风险显著增加，并显著降低与APEX 148和BRCA 2 372变异相关的风险。在过去一年中，完成了第1版剂量评估，提供了1916年至1984年工作的每名技术人员的年度和累积职业徽章剂量（个人剂量当量）估计数，以及器官和组织吸收剂量，包括骨髓、女性乳房、甲状腺、卵巢、睾丸、肺和皮肤。年剂量被定义为密度分布，以考虑估计值中的不确定性。在调整其他主要乳腺癌风险因素的分析中，发现乳腺癌发病率与累积平均乳腺剂量（ERR=2.32）和基于100次乳腺剂量蒙特卡罗实现（ERR=3.96）的统计学显著线性剂量-反应关系。明年将进行第三次后续调查，将扩大遗传研究，以纳入前瞻性生物标本收集，并将进一步完善剂量评估。 俄罗斯核工人暴露于钚后的癌症死亡率 目前正在对一批26 000名Mayak核设施工人（前苏联）进行研究，因为他们是长期暴露于高剂量外部辐射和钚的独特职业群体。评估外部辐射照射影响的分析表明，白血病和所有实体癌都存在剂量-反应关系。对Mayak工人的死亡率分析表明，体内接触钚导致患骨癌和肝癌的风险过高，女性的风险高于男性。正在进行分析，评估肺癌，肝癌和骨癌的风险作为器官剂量的函数。 清洁工人白血病和其他癌症的发病率 目前正在对切尔诺贝利清理工人进行几项研究。1998年的癌症发病率正在三个队列中进行评估，其中包括来自爱沙尼亚、拉脱维亚和立陶宛的17，000名清理工人，他们在1986年反应堆事故后被派往Chornovich（乌克兰）。此外，在能源部和核管制委员会的支持下，国家癌症研究所正在对乌克兰大约11万名切尔诺贝利清理工人进行白血病和其他血液病的“巢式”研究。 飞行人员乳腺癌和其他癌症的发病率及染色体畸变 一项癌症发病率研究正在进行中，以确定女性空乘人员是否因宇宙辐射暴露而增加患乳腺癌或其他癌症的风险。一项旨在评估宇宙辐射照射的生物剂量学研究将通过荧光原位杂交对78名飞行员和50名飞行经验最少的大学教员的染色体畸变的诱发和持续性进行比较。

Cancer and Other Mortality Risks in a Cohort of U.S. Radiologic Technologists In 1982, the Radiation Epidemiology Branch (REB), in collaboration with the University of Minnesota, initiated a nationwide cohort study of cancer incidence and mortality among 146,022 U. S. radiologic technologists. The cohort is 73% female, offering a rare opportunity to study effects of protracted low- to moderate-dose radiation exposure on breast and thyroid cancer, the two most sensitive organ sites for radiation carcinogenesis in women. Other cancer and non-cancer serious disease outcomes are also being evaluated in relation to protracted low-to-moderate dose exposures. Major findings since 2001 include: Mortality risks for breast cancer increased significantly with increasing number of years worked before 1950; mortality from cerebrovascular diseases increased significantly with earlier year first worked and with number of years worked before 1950; significantly elevated risks were found for incident cancers of the breast (female), thyroid, and melanoma compared to SEER and adjusted for non-response. Internal cohort analyses revealed significantly elevated incidence risks for breast cancer associated with working before 1940, melanoma and non-melanoma skin cancers related to working before 1950, modest elevated risk for non-chronic lymphocytic leukemia related to working >5 years before 1950, and a suggested elevated risk for thyroid cancer with working before 1960, while no associations were found for lung cancer. Mutational analysis of ZBRK1 and BRIP1 genes revealed that mutations in these genes are unlikely to account for a significant fraction of inherited breast cancer; kin-cohort analyses of breast cancer among first-degree relatives found a non-significant elevated risk associated with HER2 variant status of probands, significantly increased risks associated with XRCC1 194 and BRIP1 919 variants, and significantly reduced risks associated with APEX 148 and BRCA2 372 variants. During the past year, a Version 1 dose assessment was completed, providing estimates of annual and cumulative occupational badge doses (personal dose equivalent) for each technologist for each year worked from 1916 through 1984, as well as absorbed doses to organs and tissues including bone-marrow, female breast, thyroid, ovary, testes, lung and skin. The annual doses are defined as density distributions to account for uncertainties in the estimates. In analyses adjusted for other major breast cancer risk factors, statistically significant linear dose-response relationships were found for breast cancer incidence with cumulative mean breast dose (ERR=2.32) and based on 100 Monte Carlo realizations of breast dose (ERR=3.96). During the coming year, a third follow-up survey will be conducted, the genetic studies will be expanded to incorporate a prospective biospecimen collection, and additional refinements will be made to the dose assessment. Cancer Mortality in Russian Nuclear Workers Exposed to Plutonium A cohort of 26,000 Mayak nuclear facility workers (in the former Soviet Union)is being studied because they comprise a unique occupational group for protracted exposure to external radiation at high doses, and exposure to plutonium. Analyses evaluating the effects of external radiation exposure showed dose-response relationships for leukemia and all solid cancers. Mortality analyses of the Mayak workers demonstrate that internal exposure to plutonium results in excess risk of bone and liver cancer, with higher risks for females than males. Analyses are underway that evaluate risk of lung, liver, and bone cancer as a function of doses to the organs. Leukemia and Other Cancer Incidence in Chornobyl Clean-Up Workers Several studies of Chornobyl clean-up workers are currently underway. Cancer incidence through 1998 is being evaluated in three cohorts, comprising 17,000 clean-up workers, from Estonia, Latvia, and Lithuania, who were sent to Chornobyl (Ukraine) following the reactor accident in 1986. In addition, with support from DOE and NRC, NCI is conducting a "nested" study of leukemia and other hematologic disease among the approximately 110,000 Chornobyl clean-up workers in Ukraine. Incidence of Breast and Other Cancers and Chromosome Aberrations in Flight Personnel A cancer incidence study is underway to determine whether female flight attendants are at increased risk of breast or other cancers due to cosmic radiation exposure. A biodosimetry study to assess cosmic radiation exposure will compare the induction and persistence of chromosome aberrations by fluorescence in situ hybridization (FISH) among 78 pilots compared with 50 university faculty with minimal flying experience.