Department of Epidemiology, Human Genetics and Environmental Sciences, Southwest Center for Occupational and Environmental Health, The University of Texas Health Science Center at Houston (UTHealth) School of Public Health, 1200 Pressler Street, Houston, TX, 77030, USA.
Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, TX, 78701, USA.
J Expo Sci Environ Epidemiol. 2019 Jun;29(4):510-519. doi: 10.1038/s41370-019-0126-5. Epub 2019 Feb 15.
Epidemiology studies relying on one address to assign exposures over time share common methodological limitations in failing to account for mobility that may introduce potential exposure misclassification. Using Texas birth certificate and cancer registry data, we identified predictors of residential mobility among mothers of children diagnosed with early childhood leukemia in Texas from 1995 to 2011. We used U.S. Environmental Protection Agency (EPA) National Air Toxics Assessment data to estimate residential levels of benzene and 1,3-butadiene based on addresses at birth and diagnosis and applied mixed-effects ordinal logistic regression models to evaluate differences in exposure classification between the two time periods. In total, 55% of children moved from time of birth to diagnosis, although they generally did not move far (median distance moved was 8 km). Predictors of mobility, at delivery, included younger age, being unmarried and living in neighborhoods with high benzene levels, and, at diagnosis, increasing child's age and living in neighborhoods with low poverty rates. We observed that the odds of being assigned to a higher exposure quartile at diagnosis relative to the time of birth decreased by 31% for 1,3-butadiene (OR = 0.69, 95% CI 0.59-0.82) and by 12% for benzene (OR = 0.88, 95% CI 0.75, 1.05).
流行病学研究依赖于一个地址来随时间分配暴露，因此存在共同的方法学局限性，无法考虑可能导致潜在暴露分类错误的迁移。我们使用德克萨斯州出生证明和癌症登记处的数据，确定了 1995 年至 2011 年期间在德克萨斯州被诊断患有幼儿白血病的儿童的母亲的居住流动性的预测因素。我们使用美国环境保护署（EPA）国家空气毒物评估数据，根据出生和诊断时的地址来估计苯和 1,3-丁二烯的居住水平，并应用混合效应有序逻辑回归模型来评估两个时间段之间暴露分类的差异。总的来说，55%的儿童在出生到诊断期间搬家，尽管他们通常搬得不远（搬家的中位数距离为 8 公里）。分娩时的流动性预测因素包括年龄较小、未婚以及居住在苯含量高的社区，诊断时的流动性预测因素包括儿童年龄增加和居住在贫困率低的社区。我们观察到，与出生时相比，在诊断时被分配到更高暴露四分位的可能性对于 1,3-丁二烯降低了 31%（OR=0.69，95%CI 0.59-0.82），对于苯降低了 12%（OR=0.88，95%CI 0.75, 1.05）。
