Preston-Martin S, Navidi W, Thomas D, Lee P J, Bowman J, Pogoda J
Department of Preventive Medicine, University of Southern California School of Medicine, Los Angeles 90033-9987, USA.
Am J Epidemiol. 1996 Jan 15;143(2):105-19. doi: 10.1093/oxfordjournals.aje.a008717.
A measurement study of residential magnetic fields and brain tumors in children that was added onto an ongoing case-control interview study in Los Angeles County, California, include 298 children under age 20 years with a primary brain tumor diagnosed from 1984 to 1991 and 298 control children identified by random digit dialing. Magnetic fields were determined for all Los Angeles homes where these 596 children lived from conception to diagnosis (1,131 homes) by mapping and coding the wiring configurations outside the home and by taking a series of exterior spot and profile measurements. In addition, for a subset of subjects (35%; 211 homes) 24-hour measurements were taken in the child's room and one other room. Although measured fields are consistently highest in the highest of the five wire code categories, fields in homes in this category are much lower in Los Angeles than in Denver, where the code originated. Brain tumor risk appears not to relate to measured fields inside (p for trend for child's room = 0.98) or outside (p for trend for front wall = 0.82) the home. An apparent increase in risk among children living at diagnosis in homes with underground wiring appears to be an artifact introduced by using current controls for historical cases because this apparent excess risk disappeared in an analysis restricted to the later years of the study when cases and controls were accrued concurrently. Our study does not show an overall association of pediatric brain tumors with measured fields, with "very high" wiring configurations, or with any of several other potential sources of exposure, such as use of various electrical appliances, but the prevalence of high fields (> 2 mG) and very high fields (> 3 mG) in Los Angeles homes was too low to detect a moderate effect of the magnitude reported in other studies.
一项关于儿童居住环境磁场与脑肿瘤的测量研究被纳入了加利福尼亚州洛杉矶县正在进行的病例对照访谈研究中。该研究包括298名20岁以下的儿童，他们在1984年至1991年间被诊断出患有原发性脑肿瘤，以及通过随机数字拨号确定的298名对照儿童。通过绘制和编码房屋外部的布线配置，并进行一系列外部点测量和剖面测量，确定了这596名儿童从受孕到诊断期间居住的所有洛杉矶家庭（1131所房屋）的磁场。此外，对于一部分受试者（35%；211所房屋），在儿童房间和另一个房间进行了24小时测量。尽管在五个电线代码类别中最高的类别中测量到的磁场始终最高，但洛杉矶这类房屋中的磁场比该代码起源地丹佛的要低得多。脑肿瘤风险似乎与房屋内（儿童房间趋势p值 = 0.98）或房屋外（前墙趋势p值 = 0.82）测量到的磁场无关。在诊断时居住在有地下布线房屋中的儿童中，风险明显增加似乎是由于对历史病例使用当前对照引入的假象，因为在仅限于研究后期同时累积病例和对照的分析中，这种明显的额外风险消失了。我们的研究没有显示出小儿脑肿瘤与测量到的磁场、“非常高”的布线配置或其他几种潜在暴露源（如使用各种电器）之间的总体关联，但洛杉矶家庭中高磁场（> 2 mG）和非常高磁场（> 3 mG）的患病率过低，无法检测到其他研究报告的中等程度影响。
