IOWA AND MISSOURI RADON LUNG CANCER STUDIES

根据对地下矿工的研究推断出的风险估计， 预测居民氡子体暴露量约占 在美国，每年有19,000人死于肺癌。既往病例对照 流行病学研究，这些研究考察了居民和 氡暴露和肺癌，缺乏验证这些风险的能力 估计。对氡暴露的剂量评估不准确，很高的百分比 代理调查对象、不充分的病理检查和较低的住宅氡 集中暴露导致错误分类并限制了解释 这些研究中。爱荷华州氡肺癌I期研究旨在 克服其中的许多限制。第一阶段的研究使用了先进的氡 剂量评估，独立的组织学审查，以及研究人群 其特点是地理稳定，活病例比例高，以及 可能会有高氡暴露。第一阶段研究表明，暴露于 居民区的氡气会增加患肺癌的风险。至 为了完善这些估计，我们现在提出第二阶段研究，以检查 居民氡产品(子体)暴露量与大气环境污染的关系 肺癌的发展。因为氡子体会产生实际的辐射 对肺组织的剂量，而不是氡气本身，以减少 进一步的照射错误分类，氡剂量估计需要考虑到 计算住宅氡子体暴露量。这需要测量实际 气载氡子体浓度和累积氡暴露 随着时间的推移，后代。第二阶段的研究将得出更准确的回溯 用一种新的回溯性氡子体积分估算氡剂量值 基于玻璃的探测器。《特指目标I》考察了暴露于 住宅区氡子体与发展成肺的风险增加有关 癌症，在控制了混杂因素之后。我们将进行现场校准 和实验室验证的回溯性氡“玻璃”探测器，以及 通过纳入氡子体暴露来分析风险估计，而不是 而不是暴露在氡气中。特定目标II将确定形状是否 剂量反应曲线最好地描述了 居民氡子体暴露与肺癌风险呈线性或非线性关系。 特定目标三将审查暴露于氡子体是否有助于 腺癌的发展以及其他肺癌的组织学 类型。对于AIMS II和AIMS III，我们将使用风险暴露估计的汇集分析 源自可追溯的氡子体“玻璃”探测器，用于 来自爱荷华州和密苏里州氡肺癌研究的受试者。汇聚的 来自相似地域的两项大规模流行病学研究之间的数据 地区，爱荷华州和密苏里州，将允许我们增加样本大小和统计 权力。

Risk estimates, extrapolated from studies of underground miners, predict that residential radon progeny exposure accounts for approximately 19,000 lung cancer deaths each year in the United States. Previous case-control epidemiologic studies, which examined the relationship between residential radon exposure and lung cancer, lacked the ability to verify these risk estimates. Inaccurate dose assessment of radon exposure, a high percentage of proxy respondents, inadequate pathologic review, and low residential radon concentrations led to exposure misclassification and limited the interpretation of these studies. The Iowa Radon Lung Cancer Phase I study was designed to overcome many of these limitations. The Phase I study utilized advanced radon dose assessments, independent histologic review, and a study population that was characterized by geographic stability, high percentage of live cases, and potential for high radon exposure. The Phase I study demonstrated that exposure to residential radon gas increases the risk of developing lung cancer. To refine these estimates, we now propose Phase II studies that examine the association between residential radon product (progeny) exposure and the development of lung cancer. Because radon progeny deliver the actual radiation dose to the lung tissues, rather than radon gas itself, in order to reduce further the exposure misclassification, radon dose estimates need to take into account exposure to residential radon progeny. This requires measuring actual airborne radon progeny concentrations and integrating the exposure to radon progeny over time. The Phase II study will derive more accurate retrospective radon dose estimates by using a novel retrospective radon progeny integrating glass-based detector. Specific Aim I examines the hypothesis that exposure to residential radon progeny is associated with increased risk of developing lung cancer, after controlling for confounders. We will perform field calibration and laboratory validation of the retrospective radon "glass" detectors, and analyze the risk estimates by incorporating exposures to radon progeny, rather than exposures to radon gas. Specific Aim II will determine whether the shape of the dose response curve that best describes the relationship between residential radon progeny exposure and lung cancer risk is linear or nonlinear. Specific Aim III will examine whether exposure to radon progeny contributes to the development of adenocarcinoma, as well as other lung cancer histologic types. For Aims II and III we will use pooled analyses of exposure estimates that are derived from retrospective radon progeny "glass" detectors for subjects from the Iowa and Missouri Radon Lung Cancer Studies. The pooling of data between two large-scale epidemiologic studies from a similar geographic area, Iowa and Missouri, will allow us to increase sample size and statistical power.