Exposure To Radon And Cancer Risk

我们开展了一项与氡居住暴露相关的肺癌风险病例对照研究。该研究测量了所有成人住所以及重要的儿童住所的氡水平，并试图考虑到家庭内部和时间的暴露变化。这项研究包括男性和女性，吸烟者和不吸烟者，以探索吸烟和氡之间可能的相互作用。该研究包括1474例病例和1811例对照。只有129例肺癌患者从未吸烟，但大多数患者在癌症诊断时都不吸烟。平均氡暴露水平较低；在犹他州，测量家庭的平均水平为1.5 pCi/L，康涅狄格州为0.9 pCi/L。只有3%的康涅狄格州家庭和7%的犹他州家庭超过了美国环保署的“行动水平”4 pCi/L。我们计算了所有参与者的累积和平均氡暴露估计。在控制了特定十年的吸烟和其他相关变量和相互作用后，估计了与氡相关的过量相对风险。虽然我们的结果似乎与其他研究一致，包括基于矿工的推断，但在这项研究中，几乎没有证据表明与氡有关的肺癌的相对风险过高。当数据局限于不需要代理数据的参与者、在20年感兴趣的暴露窗口期间具有完全覆盖（即没有估算数据）的参与者、不吸烟者或康涅狄格州的参与者时，估计值更高，但没有统计显著性结果。我们发现肺癌风险的增加与TSP平均暴露量的增加有关。风险主要在康涅狄格州增加，那里的TSP可能比犹他州更好地标记空气污染中的致癌物质。肺癌风险随TSP水平的升高而增加。吸烟和TSP的影响似乎是倍增的。本研究的氡数据已与北美其他病例对照研究的数据汇总，以便更精确地估计与低剂量住宅氡暴露有关的风险。一篇报告汇集数据结果的专著已经准备好出版，一篇总结汇集结果的简短论文已经提交出版

We carried out a case-control study of lung cancer risk associated with residental exposure to radon. The study measured radon levels in all adult residences as well as in a significant childhood residences and attempted to take into account exposure variations within a home and over time. The study included men and women and both smokers and non-smokers in order to explore possible interactions between smoking and radon. The study includes 1474 cases and 1811 controls. Only 129 of the lung cancer cases had never smoked, but most were nonsmokers at the time of cancer diagnosis. The average radon exposure levels were low; the average level in measured homes was 1.5 pCi/L in Utah and 0.9 pCi/L in Connecticut. Only 3% of Connecticut homes and 7% of Utah homes exceeded the US EPA's "action level" of 4 pCi/L. We calculated cumulative and average radon exposure estimates for all participants. The excess relative risk associated with radon was estimated after controlling for decade-specific smoking and other relevant variables and interactions. While our results appear to be consistent with those of other studies - including extrapolations based on miners, there is little evidence of any excess relative risk of lung cancer associated with radon in this study. Estimates were greater when data were restricted to participants who did not require proxy data, to those with complete coverage (i.e no imputed data) during the 20-year exposure window of interest, to nonsmokers, or to Connecticut, but no result is statistically significant. We found an increase in lung cancer risk associated increasing average exposure to TSP. Risk was increased predominantly in Connecticut, where TSP may be a better marker of carcinogenic agents in air pollution than in Utah. Lung cancer risk increased with increasing level of TSP. The effects of smoking and TSP appeared to be multiplicative. Radon data from this study have been pooled with data from other case-control studies in North America for a more precise estimate of risk associated with low-dose residential radon exposure. A monograph reporting results from the pooled data has been prepared for publication and a brief paper summarizing the results of the pooling has been submitted for publication