Green L M, Miller A B, Villeneuve P J, Agnew D A, Greenberg M L, Li J, Donnelly K E
Department of Public Health Sciences, University of Toronto, Canada.
Int J Cancer. 1999 Jul 19;82(2):161-70. doi: 10.1002/(sici)1097-0215(19990719)82:2<161::aid-ijc2>3.0.co;2-x.
A population-based case-control study was conducted in Ontario, Canada, to assess the relation between the risk of childhood leukemia and residential exposure to magnetic fields. Participating subjects consisted of 201 cases, diagnosed at 0 to 14 years of age during 1985-1993, ascertained from the records at the Hospital for Sick Children (Toronto), and 406 individually matched controls. Where possible, point-in-time measurements of magnetic fields were made in all residences occupied by subjects during the period of inquiry in the defined catchment area. Three different classification schemes of wire code were assigned to each residence. Detailed information was collected by interviewer-administered questionnaires, which enabled risk estimates to be adjusted for socio-economic characteristics, medical history of parent(s) and child and environmental exposures. Inconsistent elevations in risk were associated with time-weighted averages of magnetic fields both inside and outside the home for subjects having residential point-in-time measurements that represented at least 70% of their etiological period. These risks increased in magnitude when analysis was restricted to children under 6 years of age at diagnosis or to those with acute lymphoblastic leukemia. For children younger than 6 years at diagnosis, outside perimeter measurements of the residence, > or = 0.15 microT, were associated with increased leukemia risk (OR = 3.45, 95% CI = 1.14-10.45). Evaluation of different exposure times for point-in-time magnetic field measurements and wire configuration suggested that exposures earliest in the etiological period were associated with greater risks for children diagnosed at a younger age (OR = 2.50, 95% CI = 1.14-5.49). Our findings did not support an association between leukemia and proximity to power lines with high current configuration.
在加拿大安大略省开展了一项基于人群的病例对照研究，以评估儿童白血病风险与居住环境中磁场暴露之间的关系。参与研究的对象包括201例病例，这些病例于1985年至1993年期间被确诊为0至14岁，是从多伦多病童医院的记录中确定的，以及406名个体匹配的对照。在可能的情况下，在规定集水区调查期间，对研究对象居住过的所有住所进行了磁场的即时测量。为每个住所分配了三种不同的电线编码分类方案。通过访员管理的问卷收集了详细信息，这使得能够根据社会经济特征、父母和孩子的病史以及环境暴露情况对风险估计进行调整。对于居住即时测量值占其病因期至少70%的研究对象，风险的不一致升高与家中内外磁场的时间加权平均值有关。当分析仅限于诊断时年龄小于6岁的儿童或急性淋巴细胞白血病患者时，这些风险的幅度会增加。对于诊断时年龄小于6岁的儿童，住所周边外部测量值≥0.15微特斯拉与白血病风险增加相关（比值比=3.45，95%可信区间=1.14-10.45）。对即时磁场测量的不同暴露时间和电线配置的评估表明，病因期最早的暴露与诊断时年龄较小的儿童的更大风险相关（比值比=2.50，95%可信区间=1.14-5.49）。我们的研究结果不支持白血病与靠近高电流配置的输电线之间存在关联。
