Background and objective: Qujing, located in Southwest China, is an area with an extremely high lung cancer incidence. Combustion of coal has exposed local people to great health hazards. The aim of this study is to achieve a thorough understanding of the relationship between environmental pollution and the high incidence of lung cancer in Qujing, Yunnan Province, China. The results would provide a scientific basis and support for the etiology of lung cancer, as well as suggestions on improving the environmental conditions in the area.
Methods: A total of 280 rural villages were selected through stratified cluster random sampling. Environmental background and pollution were investigated, including details on fuel type, coking plant, metal smelting, and chemical plant, among others. Logistic regression analysis was used to analyze the investigated factors.
Results: Out of the total number of local villages studied, 78.1% of those with high incidence often use smoky coal and coking. On the other hand, 78.8% of the low-incidence areas use smokeless coal or wood. Logistic regression analysis indicated that the coal type used for everyday life was a main risk factor related to lung cancer (P<0.05). Using smoky and coking coals create an alarmingly high risk for developing lung cancer. Meanwhile, smokeless coals and wood seemed to have no significant relationship to the lung cancer incidence.
Conclusions: The fuel type used for everyday life is an important factor in the high incidence of lung cancer in Qujing. Evidently, the use of smoky coal and coke increased the incidence of lung cancer, whereas smokeless coal and wood seem to bring about the contrary.
背景与目的: 我国云南省东北部的曲靖是全世界肺癌高发地区之一，当地居民长期暴露在燃煤烟气中，本研究旨在全面了解我国云南曲靖肺癌高发区的环境背景和污染情况，为肺癌病因学研究提供科学依据，同时也为改善环境状况提供数据支持。
方法: 采用多阶段、分层、整群、概率抽样方法随机抽取280个自然村，了解当地自然村使用燃料的种类、附近有无炼焦厂、铁锌厂、化工厂等环境背景和污染情况，并采用二项Logistic回归分析方法对调查因素进行分析。
结果: 高发区78.1%的自然村使用烟煤和焦煤，低发区78.8%的自然村使用无烟煤和木柴。二项Logistic回归分析方法显示，上述因素中仅有燃料种类进入方程（P < 0.05），烟煤和焦煤的使用与肺癌高发具有正关联作用，而使用木柴、无烟煤不会对肺癌的高发产生影响。
结论: 当地居民使用燃料类型是影响肺癌高发的重要因素，其中烟煤和焦煤对当地肺癌高发有促进作用，而无烟煤或者木柴作用不大或有抑制作用。