Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, North Bethesda, Maryland, USA.
Program in Epidemiology, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.
J Expo Sci Environ Epidemiol. 2014 Jan-Feb;24(1):9-16. doi: 10.1038/jes.2012.86. Epub 2012 Aug 22.
The epidemiologic evidence for the carcinogenicity of lead is inconsistent and requires improved exposure assessment to estimate risk. We evaluated historical occupational lead exposure for a population-based cohort of women (n=74,942) by calibrating a job-exposure matrix (JEM) with lead fume (n=20,084) and lead dust (n=5383) measurements collected over four decades in Shanghai, China. Using mixed-effect models, we calibrated intensity JEM ratings to the measurements using fixed-effects terms for year and JEM rating. We developed job/industry-specific estimates from the random-effects terms for job and industry. The model estimates were applied to subjects' jobs when the JEM probability rating was high for either job or industry; remaining jobs were considered unexposed. The models predicted that exposure increased monotonically with JEM intensity rating and decreased 20-50-fold over time. The cumulative calibrated JEM estimates and job/industry-specific estimates were highly correlated (Pearson correlation=0.79-0.84). Overall, 5% of the person-years and 8% of the women were exposed to lead fume; 2% of the person-years and 4% of the women were exposed to lead dust. The most common lead-exposed jobs were manufacturing electronic equipment. These historical lead estimates should enhance our ability to detect associations between lead exposure and cancer risk in the future epidemiologic analyses.
职业性铅暴露与癌症关系的流行病学证据并不一致,需要改善暴露评估以估计风险。我们通过校准职业暴露矩阵(JEM),评估了中国上海 40 年来采集的 20084 例铅烟和 5383 例铅尘测量值,对一个基于人群的女性队列(n=74942)的历史职业性铅暴露进行了评估。我们使用混合效应模型,通过职业和 JEM 等级的固定效应项,将强度 JEM 评分与测量值进行校准。我们从职业和行业的随机效应项中开发了职业/行业特定的估计值。当 JEM 对职业或行业的概率评分很高时,该模型将估计值应用于受试者的工作;其余工作被认为未暴露。模型估计表明,暴露随着 JEM 强度评分的增加而单调增加,且随时间减少 20-50 倍。累积校准 JEM 估计值和职业/行业特定估计值高度相关(Pearson 相关系数=0.79-0.84)。总体而言,5%的人年和 8%的女性接触铅烟;2%的人年和 4%的女性接触铅尘。最常见的铅暴露职业是制造电子设备。这些历史铅暴露估计值应增强我们在未来的流行病学分析中检测铅暴露与癌症风险之间关联的能力。