Background: Smoking is a major cause of lung cancer. Studies of lung cancer among miners have shown that occupational exposure also played an important role. The aim of this study is to investigate radon, cigarette use and other risk factors of lung cancer in Yunnan tin miners and to provide a scientific basis for the prevention and control of occupational lung cancer.
Methods: A prospective cohort study was conducted among Yunnan tin miners, the associations between potential risk factors for lung cancer were analyzed by multivariate Cox regression model. Effects of age at first radon exposure and radon exposure rate on lung cancer risk were analyzed. The relationship between cumulative working level month and lung cancer was analyzed according to smoking status. The joint effect of tobacco use and cumulative radon exposure was analyzed based on additive and multiplicative models.
Results: Increased risk of lung cancer was associated with age at enrollment, tobacco use, prior bronchitis, and cumulative arsenic and radon exposure, while higher education level was associated with decreased lung cancer risk. An inverse effect of radon exposure rate was observed. There was no significant association between lung cancer risk and first radon exposure age. There was a significant additive interaction between tobacco use and radon exposure on lung cancer risk.
Conclusions: Several risk factors may contribute to the high incidence of lung cancer in Yunnan tin miners. Further studies are warranted to evaluate joint effect of different risk factors.
背景与目的 吸烟是肺癌的主要病因，在矿工肺癌病因的研究中发现，职业暴露因素也起重要作用。本研究旨在分析氡暴露、吸烟等危险因素对云锡矿工肺癌的影响，为预防和控制肺癌高发提供科学依据。方法 利用前瞻性队列研究方法，对云锡矿工肺癌高危人群暴露因素对肺癌死亡的影响进行Cox多因素分析；分析矿工肺癌危险与初始氡暴露年龄及氡暴露率的关系，分析不同吸烟、氡暴露水平下肺癌死亡的危险，并对吸烟和累积氡暴露量之间的交互作用进行分析。结果 进入研究时的年龄、吸烟量、累积氡砷暴露、既往慢性支气管炎为云锡矿工肺癌的独立危险因素，教育程度是矿工肺癌的保护性因素；肺癌危险与氡暴露率间存在逆剂量率效应，但与初始氡暴露年龄无明显关联；吸烟和氡暴露对肺癌危险有显著的相加交互作用。结论 云锡矿工肺癌高死亡率是多种因素共同作用的结果，危险因素间的交互作用值得进一步深入研究。