EXPOSURE TO RADON AND CANCER RISK

目的：1)在考虑主动和被动暴露于香烟烟雾的情况下，评估终生居住暴露于氡和肺癌风险的作用。2)汇集其他住宅氡暴露研究的数据，并将观察到的风险估计值与根据铀矿工人研究预测的风险估计值进行对比，从而有助于国家对氡暴露相关风险的估计。2)探索肺癌的其他危险因素，包括通过与地理数据系统的联系确定的环境暴露。感兴趣的因素包括颗粒物空气污染、饮用水中的砷、海拔以及从个人访谈中确定的许多职业、医疗和生活方式因素。3)探讨住宅氡暴露与儿童癌症风险的关系。成就：现已完成数据分析，以评估与住宅氡暴露有关的肺癌和儿童白血病风险。对于肺癌的研究，已经创建了一个统一的数据结构，使我们能够连接一个复杂的，多层次的数据集。已对居住地址进行地理编码，以便与有关家庭氡水平因素的地理数据库建立联系。还确定了与氡水平有关的住房特征，并评估了处理缺失暴露数据的方法。虽然氡水平低于预期，但我们对感兴趣的暴露时间窗的覆盖范围相当好。20%的研究对象完全覆盖了诊断前25岁至5岁之间的年龄。60%的患者在诊断或面谈前25至5年有完整的数据。结果表明，所研究的低剂量氡对肺癌的总体风险很小，但数据与根据已知对矿工的影响推断的估计是一致的。已经获得了关于空气污染微粒物质的数据，并制定了一项绘图策略，以估计研究样本中所有房屋的暴露情况。地图已经完成，分析已经开始评估这种接触与肺癌风险之间的联系。将采用类似的方法将居民与饮用水中砷的信息联系起来。其他分析将侧重于高风险亚型和其他肺癌风险因素，如环境烟草烟雾暴露、职业因素、海拔和既往肺部疾病。

Aims:1) To assess the role of lifetime residential exposure to radon and risk of lung cancer while taking into account active and passive exposure to cigarette smoke. 2) To contribute to national estimates of risk associated with radon exposure by pooling data with other studies of residential radon exposure and contrasting observed risk estimates with those predicted based on studies of uranium miners. 2) To explore other risk factors for lung cancer, including environmental exposures ascertained through linkage with geographically based data systems. Factors of interest include particulate matter air pollution, arsenic in drinking water, altitude, and numerous occupational, medical, and lifestyle factors ascertained from personal interviews. 3) To explore the risk for childhood cancers associated with residential radon exposure. Accomplishments: Data analysis has now been completed to assess lung cancer and childhood leukemia risk associated with residential radon exposure. For the lung cancer study, a uniform data structure has been created, allowing us to link a complex, multi-level data set. Residence addresses have been geocoded to facilitate linkage with geographical databases on factors associated with radon levels in homes. Housing characteristics associated with radon levels have also been identified and methods for dealing with missing exposure data have been evaluated. Although radon levels are lower than predicted, our coverage of the exposure time-window of interest is quite good. 20% of study subjects have complete coverage of the years between age 25 and 5-years before diagnosis. 60% have complete data for the years between 25 and 5 years prior to diagnosis or interview. Results suggest little overall lung cancer risk from radon at the low doses studied, but the data are consistent with estimates based on extrapolating from known effects in miners. Data on particulate matter air pollution have been obtained and a mapping strategy has been devised to estimate exposures for all houses in the study sample. Maps have been completed and analysis has begun to evaluate the link between this exposure and lung cancer risk. A similar approach will be used to link residences to information on arsenic in drinking water. Additional analyses will focus on high risk subtypes and other lung cancer risk factors such as environmental tobacco smoke exposure, occupational factors, altitude, and prior lung disease.