Langholz Bryan, Ebi Kristie L, Thomas Duncan C, Peters John M, London Stephanie J
Department of Preventive Medicine, University of Southern California, Los Angeles, CA 90089-9011, USA.
Ann Epidemiol. 2002 Oct;12(7):482-7. doi: 10.1016/s1047-2797(01)00317-9.
To investigate the relationship between traffic density and the risk of childhood leukemia.
The study group consisted of 212 cases and 202 controls from the London et al. (1991) study of childhood leukemia conducted in the Los Angeles area during 1978 to 1984. Using GIS methods, traffic counts on all streets within 1500 feet of each subject's residence of longest duration were determined. From these counts, an integrated distance-weighted traffic density measure was calculated for each subject for use as the analytic variable. Additional information, including magnetic fields and wire-code, was obtained from the original case-control study. Association between traffic density and leukemia, and confounding and effect modification by other variables, were assessed using standard matched case-control analyses.
Although the unadjusted traffic density-childhood leukemia rate ratios were slightly elevated, this weak association was explained by confounding by wire code. Wire code remained associated with leukemia after controlling for traffic density. There was little evidence of effect modification between traffic density and magnetic fields, wire code or other variables.
There is no evidence of an association of traffic density with childhood leukemia in the Los Angeles case-control study.
研究交通密度与儿童白血病风险之间的关系。
研究组由212例病例和202例对照组成，这些病例和对照来自1978年至1984年在洛杉矶地区进行的伦敦等人（1991年）关于儿童白血病的研究。使用地理信息系统（GIS）方法，确定每位受试者居住时间最长的住所1500英尺范围内所有街道的交通流量计数。根据这些计数，为每位受试者计算一个综合的距离加权交通密度测量值，用作分析变量。其他信息，包括磁场和电线编码，从原始病例对照研究中获取。使用标准匹配病例对照分析评估交通密度与白血病之间的关联，以及其他变量的混杂和效应修正。
尽管未调整的交通密度与儿童白血病发病率比值略有升高，但这种微弱关联可通过电线编码的混杂来解释。在控制交通密度后，电线编码仍与白血病相关。几乎没有证据表明交通密度与磁场、电线编码或其他变量之间存在效应修正。
在洛杉矶病例对照研究中，没有证据表明交通密度与儿童白血病有关联。
