摘要目的 用固定队列研究方法研究温石棉矿工接触石棉粉尘量与肺癌发病的剂量反应关系,探讨不同石棉暴露剂量下的肺癌发病规律.方法 从2009年7月开始,采用回顾性队列研究方法,入选条件为1981年1月1日至1988年12月31日登记在册,工龄满1年,没有明显心肺疾病者,将符合标准的1932例石棉矿工纳入队列,追踪29年(1981至2009年),记录接尘矿工的个人信息、职业史、疾病史、健康资料,收集该矿历年粉尘浓度监测资料.应用寿命表法建立石棉尘质量浓度的剂量反应关系,拟合剂量患病概率回归方程,估算不同工作年限不同粉尘浓度下肺癌超额发病率.结果 工人累积接尘量与肺癌累积发病概率有明显的剂量反应关系,且吸烟组的肺癌累积发病概率明显高于非吸烟组.当每年累积接尘量(cumulative exposure,Ce)小于2000 mg/m3时,肺癌累积发病概率(Px)为6.58/万；当2000 mg/m3≤每年累积接尘量＜3000 mg/m3时,肺癌累积发病概率为91.72/万；当每年累积接尘量大于5000 mg/m3时,肺癌累积发病概率高达141.02/万.应用3种模型进行拟合,得出最优回归方程:Px =-0.0004 Ce2 +0.0052Ce-0.0011(r2=0.9387).开展本次研究的石棉矿生产车间2009年的平均粉尘浓度超标85倍,根据方程推测在此暴露环境下工作40年肺癌的超额发病率将达到112.598/万.结论 石棉矿工石棉累积接尘量与肺癌间存在明显的剂量反应关系,肺癌发病风险随暴露量的增加呈现上升趋势.

abstractsObjective To clarify the dose-response relationship between asbestos dust exposure and lung cancer incidence in chrysotile asbestos miners by fixed cohort study and to investigate the incidence rates of lung cancer in exposure to different concentrations of asbestos dust.Methods A retrospective cohort study was conducted in 1932 asbestos miners who registered from January 1,1981 to December 31,1988,had worked for at least 1 year,and had no obvious cardiopulmonary diseases; the cohort study began in July 2009 and covered a time span of 29 years (1981-2009).The personal information,occupational history,disease history,and health data of these miners were recorded,and the monitoring data on dust concentrations in the mine over the years were collected.The dose-response relationship between asbestos dust concentration and lung cancer incidence was established by the method of life table; a regression equation was fitted to predict the excess incidence rates of lung cancer under the conditions of different working years and dust concentrations.Results A significant dose-response relationship was observed between cumulative exposure (Ce) and cumulative probability (Px) of lung cancer incidence,and the smokers had a higher Px than nonsmokers.When Ce was less than 2000 mg/m3·each year,Px reached 6.58/10000; when Ce was not less than 2000 mg/m3·and less than 3000 mg/m3·each year,Px reached 91.72/10000; when Ce was more than 5000 mg/m3·each year,Px was as high as 141.02/10000.The three models were fitted to obtain the optimal regression equation:Px =-0.0004Ce2+ 0.0052Ce-0.0011 (r2=0.9387).In the workshop of asbestos mine in this study,the average dust concentration was 85 times higher than the limit in 2009,so the excess incidence rate of lung cancer was 112.598/10000 if the miners worked under this condition for 40 years,according to the equation.Conclusion There is a significant dose-response relationship between cumulative asbestos exposure and lung cancer incidence in chrysotile asbestos miners.The risk for lung cancer rises as asbestos exposure increases.