Am J Epidemiol. 2013 May 1;177(9):989-96. doi: 10.1093/aje/kws343. Epub 2013 Apr 4.
We employed the parametric G formula to analyze lung cancer mortality in a cohort of textile manufacturing workers who were occupationally exposed to asbestos in South Carolina. A total of 3,002 adults with a median age of 24 years at enrollment (58% male, 81% Caucasian) were followed for 117,471 person-years between 1940 and 2001, and 195 lung cancer deaths were observed. Chrysotile asbestos exposure was measured in fiber-years per milliliter of air, and annual occupational exposures were estimated on the basis of detailed work histories. Sixteen percent of person-years involved exposure to asbestos, with a median exposure of 3.30 fiber-years/mL among those exposed. Lung cancer mortality by age 90 years under the observed asbestos exposure was 9.44%. In comparison with observed asbestos exposure, if the facility had operated under the current Occupational Safety and Health Administration asbestos exposure standard of <0.1 fibers/mL, we estimate that the cohort would have experienced 24% less lung cancer mortality by age 90 years (mortality ratio = 0.76, 95% confidence interval: 0.62, 0.94). A further reduction in asbestos exposure to a standard of <0.05 fibers/mL was estimated to have resulted in a minimal additional reduction in lung cancer mortality by age 90 years (mortality ratio = 0.75, 95% confidence interval: 0.61, 0.92).
我们采用参数 G 公式分析了南卡罗来纳州 1 个纺织制造工人队列的肺癌死亡率，这些工人在职业上接触过石棉。共有 3002 名成年人，登记时的中位年龄为 24 岁（58%为男性，81%为白种人），1940 年至 2001 年间随访了 117471 人年，观察到 195 例肺癌死亡。温石棉暴露以每毫升空气中纤维年数表示，根据详细的工作史估计每年的职业暴露。16%的人年涉及暴露于石棉，暴露者的中位暴露量为 3.30 纤维年/毫升。在观察到的石棉暴露下，90 岁时的肺癌死亡率为 9.44%。与观察到的石棉暴露相比，如果该工厂按照目前职业安全与健康管理局规定的石棉暴露标准<0.1 纤维/毫升运营，我们估计该队列在 90 岁时的肺癌死亡率将降低 24%（死亡率比=0.76，95%置信区间：0.62，0.94）。进一步将石棉暴露标准降低至<0.05 纤维/毫升，估计 90 岁时肺癌死亡率会有最小的额外降低（死亡率比=0.75，95%置信区间：0.61，0.92）。
