Liu Liqun, Wan Xia, Chen Gongbo, Ma Xiangyun, Ning Bofu, Yang Gonghuan
Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing 100730, China.
Xuanwei Center for Disease Control and Prevention, Xuanwei 655400, China.
Zhongguo Fei Ai Za Zhi. 2017 Aug 20;20(8):528-537. doi: 10.3779/j.issn.1009-3419.2017.08.05.
Since 1970s, Xuanwei in Yunnan province has been one of the towns with highest lung cancer mortality in China. Moreover, the characters of high female lung cancer mortality and sub-regional clustering high lung cancer mortality have not changed. In this study, we further described the exposure situation of risk factors of lung cancer in Xuanwei nowadays, in order to explore the trend of the distribution of lung cancer there.
Firstly we divided the 26 towns of Xuanwei city to high-, median- and low- lung cancer areas by the lung cancer mortality in 2010-2012. We chose 2 towns within each area according to topography and orientation, and randomly picked 4 villages in each town to be our study area. We did a questionnaire about lung cancer related risk factors upon the sample population in the study area. We calculated the exposure percentages of each risk factor, in whole sample population and subgroups, for nowadays and for 10 years ago (only living environmental risk factors), and compared them between areas or time points using standardized rates and the statistical test of standardized rate comparison, or chi-square test.
65%-80% male in the study area has a history of smoking; 60%-90% non-smoker has been exposed to second hand smoke. These situations are worse in high and median lung cancer areas. 50% male in median lung cancer area have coal mining work experience, which is 2 times of the percentages in the other two areas; while 15%-25% people in high lung cancer area have other occupational exposure history to particulate air pollution, which is 3-5 times of the percentages in the other two areas. From ten years ago until nowadays, 80% families in median lung cancer area use 2 tons or more smoky coal per year; more than 90% families burn coal for household heating; more than 60% families suffer from smog in the kitchen during cook; 60% families most frequently use stove in the ground with chimney. Only 20% families in high lung cancer area now use 2 tons or more smoky coal per year. Now 50%-75% families in the study area use 700 kilowatt-hours of electricity per year, much more than ten years ago. 80% residents in low lung cancer area eat fatty or pickled or smoked food at least 3 days per week; while in high and median lung cancer areas the percentages are 50%-60%.
According to data obtained in this survey, current distribution of smoky coal use has differed from the distribution of high-, median- and low- lung cancer areas. Tobacco use and second hand smoke, the use of smoky coal and occupational exposure to particulate matters could be the main risk factors for lung cancer in Xuanwei now. The relations between lung cancer and stove type, dietary habit and so on deserve further study.
自20世纪70年代以来，云南省宣威市一直是中国肺癌死亡率最高的地区之一。此外，女性肺癌死亡率高以及肺癌死亡率在局部地区聚集的特征并未改变。在本研究中，我们进一步描述了宣威市目前肺癌危险因素的暴露情况，以探索该地肺癌分布的趋势。
首先，我们根据2010 - 2012年的肺癌死亡率将宣威市的26个镇分为肺癌高发、中发和低发地区。根据地形和方位在每个地区选择2个镇，并在每个镇随机抽取4个村庄作为研究区域。我们对研究区域内的样本人群进行了关于肺癌相关危险因素的问卷调查。我们计算了当前以及10年前（仅生活环境危险因素）整个样本人群和亚组中各危险因素的暴露百分比，并使用标准化率和标准化率比较的统计检验或卡方检验在不同地区或时间点之间进行比较。
研究区域内65% - 80%的男性有吸烟史；60% - 90%的非吸烟者曾接触过二手烟。这些情况在肺癌高发和中发地区更严重。肺癌中发地区50%的男性有煤矿开采工作经历，是其他两个地区百分比的2倍；而肺癌高发地区15% - 25%的人有其他职业性接触颗粒物空气污染的历史，是其他两个地区百分比的3 - 5倍。从10年前到现在，肺癌中发地区80%的家庭每年使用2吨或更多的烟煤；超过90%的家庭烧煤用于家庭取暖；超过60%的家庭在做饭时厨房有烟雾；60%的家庭最常使用地面有烟囱的炉灶。目前肺癌高发地区只有20%的家庭每年使用2吨或更多的烟煤。现在研究区域内50% - 75%的家庭每年用电700千瓦时，比10年前多得多。肺癌低发地区80%的居民每周至少有3天食用油腻、腌制或烟熏食品；而在肺癌高发和中发地区，这一比例为50% - 60%。
根据本次调查获得的数据，目前烟煤使用的分布与肺癌高、中、低发地区的分布不同。烟草使用和二手烟、烟煤使用以及职业性接触颗粒物可能是目前宣威市肺癌的主要危险因素。肺癌与炉灶类型、饮食习惯等之间的关系值得进一步研究。
