铀矿工氡职业暴露与肺癌风险:巢式病例-对照研究

Occupational exposure to radon and lung cancer risk in uranium miners: A nested case-control study

[目的]探讨铀矿工氡职业暴露与肺癌的关系。[方法]采用回顾性巢式病例-对照研究的方法,以1958—2000年在某铀矿山工作,且由当地省市级医院确诊为肺癌的72例男性死亡病例为病例组,以与病例组年龄相差不超过5岁、同性别、1∶4配比方法选取的288例铀矿工为对照组,采用条件logistic回归方法对职业性氡暴露与肺癌关系进行分析,并计算氡致肺癌的危险系数[每工作水平月(WLM)引起的肺癌风险增量]。[结果]病例组及对照组的氡暴露量几何均数分别为171.8 WLM和127.5 WLM。单因素条件logistic回归分析显示:病例组与对照组的首次下井年龄、坑龄、年龄差异无统计学意义;吸烟(OR=1.88,95%CI:1.07~3.31)和氡职业暴露(OR=1.61,95%CI:1.19~2.16)增加肺癌风险。多因素条件logistic回归分析显示:吸烟及氡暴露仍是矿工肺癌发生的主要危险因素,吸烟致肺癌的OR为2.27(95%CI:1.26~4.09),氡致肺癌的OR为1.62(95%CI:1.18~2.24)。使用OR=1.62计算出氡致肺癌的危险系数为0.36%WLM-1,即每WLM的职业氡暴露可使铀矿工患肺癌死亡的风险增加0.36%。[结论]除吸烟外,氡职业暴露是铀矿工肺癌的主要危险因素。

[Objective] To assess the relationship between lung cancer and occupational exposure to radon in uranium miners.[Methods] By retrospective nested case-control study design, 72 male deaths who had been employed in a uranium mine from 1958 to 2000 and diagnosed as lung cancer by local prefecture-level hospitals were selected as the case group, and 288 uranium miners as the control group. Both groups were matched on age（within 5 years） and sex at a case-to-control ratio of 1∶4. Conditional logistic regression method was used to assess the relationship between occupational radon exposure and lung cancer and to calculate the risk coefficient of lung cancer contributed by radon [the increased risk of lung cancer contributed by per working level month（WLM）].[Results] The cumulative exposure doses of radon in the case group and the control group were 171.8 WLM and 127.5 WLM respectively. The results of single-factor conditional logistic regression analysis showed that there were no differences in the age for first entering wells, length of underground mining service, and age between the case group and the control group, and smoking（OR=1.88, 95%CI： 1.07-3.31） and occupational radon exposure（OR=1.61, 95%CI： 1.19-2.16） were the risk factors for lung cancer. The results of multiple conditional logistic regression analysis showed that smoking（OR=2.27, 95%CI： 1.26-4.09） and radon exposure（OR=1.62, 95%CI： 1.18-2.24） were still the risk factors for lung cancer. The risk coefficient was 0.36% WLM-1 if OR was 1.62, indicating that the occupational radon exposure per WLM increased the risk of death from lung cancer among uranium miners by 0.36%. [Conclusion] Besides smoking, occupational exposure to radon is the major risk factor for lung cancer among uranium miners.