Schnelzer Maria, Hammer Gaël P, Kreuzer Michaela, Tschense Annemarie, Grosche Bernd
Federal Office for Radiation Protection, Department of Radiation Protection and Health, Ingolstaedter Landstr. 1, 85764 Oberschleissheim, Germany.
Health Phys. 2010 Jan;98(1):20-8. doi: 10.1097/HP.0b013e3181b8ce81.
The possible confounding effect of smoking on radon-associated risk for lung cancer mortality was investigated in a case-control study nested in the cohort of German uranium miners. The study included 704 miners who died of lung cancer and 1,398 controls matched individually for birth year and attained age. Smoking status was reconstructed from questionnaires and records from the mining company's health archives for 421 cases and 620 controls. Data on radon exposure were taken from a job-exposure matrix. Smoking adjusted odds ratios for lung cancer in relation to cumulative radon exposure have been calculated with conditional logistic regression. The increase in risk per Working Level Month (WLM) was assessed with a linear excess relative risk (ERR) model taking smoking into account as a multiplicative factor. In addition, the potential impact of temporal factors on the ERR per WLM was examined. Lung cancer mortality risk increased with increasing radon exposure, yielding a crude ERR per WLM of 0.25% (95% CI: 0.13-0.46%). Adjustment for smoking led only to marginal changes of the radon-associated lung cancer risks. The adjusted ERR per WLM was very similar (0.23%, 95%-CI: 0.11-0.46%) to the crude risk and to the risk found in the Wismut cohort study. This stability of the radon-related lung cancer risks with and without adjustment for smoking suggests that smoking does not act as a major confounder in this study and presumably also not in the cohort study.
在一项嵌套于德国铀矿矿工队列中的病例对照研究中，调查了吸烟对氡气相关肺癌死亡率风险的潜在混杂效应。该研究纳入了704名死于肺癌的矿工以及1398名在出生年份和年龄上进行个体匹配的对照。通过问卷调查以及矿业公司健康档案记录，对421例病例和620名对照的吸烟状况进行了重构。氡暴露数据取自工作暴露矩阵。采用条件逻辑回归计算了与累积氡暴露相关的肺癌吸烟调整比值比。采用线性超额相对风险（ERR）模型评估了每工作水平月（WLM）的风险增加情况，并将吸烟作为一个相乘因子考虑在内。此外，还研究了时间因素对每WLM的ERR的潜在影响。肺癌死亡率风险随氡暴露增加而升高，每WLM的粗ERR为0.25%（95%置信区间：0.13 - 0.46%）。对吸烟进行调整仅导致氡相关肺癌风险出现微小变化。调整后的每WLM的ERR与粗风险以及在维姆施图特队列研究中发现的风险非常相似（0.23%，95%置信区间：0.11 - 0.46%）。无论是否对吸烟进行调整，氡相关肺癌风险都具有这种稳定性，这表明在本研究中吸烟并非主要混杂因素，在队列研究中可能也不是。
