Studies of Populations Exposed to Occupational Sources o

美国放射技术队列中的癌症和其他死亡风险1982年，辐射流行病学分部（REB）与明尼苏达大学合作，在146022名美国放射技术人员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，这为研究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。其他癌症和非癌症严重疾病的后果也正在评估与长期低至中等剂量照射有关的情况。2001年以来的主要发现包括：乳腺癌的死亡风险随着1950年以前工作年数的增加而显著增加；脑血管疾病死亡率随着首次工作年份和1950年以前工作年数的增加而显著增加；与SEER相比，发现乳腺癌（女性）、甲状腺癌和黑色素瘤的发生率显著升高，并对无反应进行了调整。内部队列分析显示，1940年以前工作的人患乳腺癌的风险显著升高，1950年以前工作的人患黑色素瘤和非黑色素瘤皮肤癌的风险显著升高，1950年以前工作的人患非慢性淋巴细胞白血病的风险适度升高，1960年以前工作的人患甲状腺癌的风险升高，而肺癌的风险未发现相关。ATM基因的突变分析表明，这些基因的突变不太可能占遗传性乳腺癌的很大一部分，但一些低频多态性可能会增加乳腺癌的风险。在过去一年中，我们完成了关于癌症和其他医疗结果、特定日历的就业因素（所进行的手术和相关保护措施）以及癌症风险因素的第三次综合调查。102,000名已知在世的第一次或第二次调查响应者中有近74,000人（72%）参加了第三次调查。我们发表了第一份乳腺癌半定量辐射风险评估报告。完成了乳腺癌的研究，并提交了一些基因通路（如ATM、双链断裂修复、碱基切除修复、细胞凋亡）的遗传多态性。在第三次调查中，我们为另外756宗乳癌个案采集静脉穿刺血样，并展开一项以邮寄方式采集DNA手指刺血样本的先导研究。此外，我们完成了Version-3.5剂量测定系统的开发。使用单个FISH测量对152个终生剂量估计的确证使我们有信心使用3.5版剂量估计进行剂量-反应分析并继续发表。暴露于钚和长期外部辐射的俄罗斯核工作人员的癌症死亡率正在对（俄罗斯联邦境内）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。暴露于外部辐射与白血病死亡率之间的剂量-反应关系得到证实；肺癌、肝癌和骨癌（作为单一类别分析）；以及除了肺癌，骨癌和肝癌以外的所有实体癌。按性别、暴露时年龄和暴露后时间划分的风险模式与在原子弹幸存者中观察到的情况大致相似。死亡率分析也清楚地表明，体内接触钚会导致患肺癌、肝癌和骨癌的风险过高，而这些部位受到的钚剂量最高。最近对肺癌死亡率进行的剂量-反应分析表明，钚对肺部的内剂量和外剂量都存在显著关联（p大于0.001）。

Cancer and Other Mortality Risks in a Cohort of U.S. Radiologic TechnologistsIn 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 the ATM genes revealed that mutations in these genes are unlikely to account for a significant fraction of inherited breast cancer but a few low-frequency polymorphisms may increase breast cancer risk. During the past year, we completed a third comprehensive survey of cancer and other medical outcomes, calendar-specific employment factors (procedures performed and related protection practices), and cancer risk factors. Nearly 74,000 of 102,000 (72%) known living first or second survey responders participated in the third survey. We published our first semi-quantitative radiation risk assessment for breast cancer. Studies of breast cancer and genetic polymorphisms in several gene pathways (e.g. ATM, double strand break repair, base excision repair, apoptosis) were completed and manuscripts submitted. Venipuncture blood samples were collected from another 756 breast cancer cases identified on the third survey, and a pilot study of DNA fingerprick blood sample collection by mail was launched. Additionally, we completed development of the Version-3.5 dosimetry system. Corroboration of 152 lifetime dose estimates using individual FISH measurements gives us confidence to use the Version 3.5 dose estimates to conduct dose-response analyses and proceed with publication.Cancer Mortality in Russian Nuclear Workers Exposed to Plutonium and Protracted External RadiationA cohort of 26,000 Mayak nuclear facility workers (in the Russian Federation) is being studied because they comprise a unique occupational group for protracted exposure to external radiation at high doses and exposure to plutonium. Dose-response relationships for exposure to external radiation were demonstrated for mortality from leukemia; cancers of the lung, liver and bone (analyzed as a single category); and all solid cancers other than lung, bone and liver cancer. Patterns of risk by sex, age at exposure and time since exposure were generally similar to those observed in A-bomb survivors. Mortality analyses have also clearly demonstrated that internal exposure to plutonium results in excess risks for cancers of the lung, liver and bone cancers, the sites receiving the highest doses from plutonium. Recently conducted dose-response analyses of lung cancer mortality indicated significant associations for both internal dose to the lung from plutonium and external dose (p greater than 0.001).