Kheifets Leeka, Swanson John, Greenland Sander
Department of Epidemiology, UCLA School of Public Health, Los Angeles, California 90095-1772, USA.
Bioelectromagnetics. 2006 Oct;27(7):545-52. doi: 10.1002/bem.20249.
During the past 25 years concern has been raised about the possible health effects of extremely low frequency (ELF) electric and magnetic fields (EMFs), particularly regarding childhood leukemia. Comparison of changes in electricity consumption (a surrogate for exposure) to changes in childhood-leukemia rates, known as ecologic correlation, have been used to argue both for and against the association between magnetic fields and childhood leukemia. In this paper we explore what can be learned from such an ecologic approach. We first examine separately the evidence on trends in exposure to EMFs and on trends in leukemia rates, and then compare the two. Both incidence rates and exposures have increased, but there are so many approximations and assumptions involved in connecting the two trends that we cannot regard the ecologic evidence as providing any meaningful evidence for or against a causal link.
在过去25年里，人们对极低频（ELF）电场和磁场（EMF）可能对健康产生的影响表示关注，尤其是关于儿童白血病。将电力消耗的变化（作为暴露的替代指标）与儿童白血病发病率的变化进行比较，即所谓的生态相关性，已被用于支持和反对磁场与儿童白血病之间的关联。在本文中，我们探讨从这种生态学方法中可以学到什么。我们首先分别研究关于EMF暴露趋势和白血病发病率趋势的证据，然后对两者进行比较。发病率和暴露量都有所增加，但在将这两种趋势联系起来时涉及如此多的近似值和假设，以至于我们不能将生态证据视为支持或反对因果联系的任何有意义的证据。
