Kavet R, Tell R A
Richard Tell Associates, Inc., Las Vegas, NV 89131.
Health Phys. 1991 Jul;61(1):47-57. doi: 10.1097/00004032-199107000-00005.
As the use of video display terminals (VDTs) has expanded, questions have been raised as to whether working at a VDT affects the risk of adverse pregnancy outcome. A particular focus for these questions has been the very low frequency (VLF) magnetic field produced by a VDT's horizontal deflection coil. VDTs also produce VLF electric fields, extremely low frequency (ELF) electric and magnetic fields, and static electric fields, Ten studies of pregnancy outcome in VDT operators have been conducted in six countries, and with one exception, none has concluded that magnetic fields from VDTs may predispose pregnant operators to spontaneous abortion or congenital malformation. The epidemiologic studies conducted thus far do not provide a basis for concluding that VDT work and adverse pregnancy outcome are associated. Studies of fetal resorptions and malformations in rodents exposed to VLF magnetic fields have produced inconsistent findings. Two laboratories in Sweden that studied mice have reported positive results, one laboratory showing field-related malformations (but not resorptions) and the other showing field-related resorptions (but not malformations). Two Canadian laboratories have reported negative results in rats and mice. Studies of avian embryos have also yielded inconsistent results, but lacking a maternal-fetal placental interface, avian embryos are a questionable model for evaluating human reproductive risks. Finally, VLF electric and magnetic fields measured at the operator position are in compliance with field strength standards and guidelines that have been established around the world.
随着视频显示终端（VDT）使用的增加，人们开始质疑在VDT前工作是否会增加不良妊娠结局的风险。这些问题特别关注的是VDT水平偏转线圈产生的极低频（VLF）磁场。VDT还会产生VLF电场、极低频（ELF）电场和磁场以及静电场。六个国家已经对VDT操作人员的妊娠结局进行了十项研究，除一项研究外，没有一项研究得出VDT产生的磁场会使怀孕操作人员易发生自然流产或先天性畸形的结论。迄今为止进行的流行病学研究并未提供证据表明VDT工作与不良妊娠结局有关。对暴露于VLF磁场的啮齿动物进行的胎儿吸收和畸形研究结果并不一致。瑞典的两个实验室对小鼠进行研究后报告了阳性结果，一个实验室显示出与磁场相关的畸形（但不是吸收），另一个实验室显示出与磁场相关的吸收（但不是畸形）。加拿大的两个实验室对大鼠和小鼠进行研究后报告了阴性结果。对鸟类胚胎的研究结果也不一致，但由于缺乏母胎胎盘界面，鸟类胚胎作为评估人类生殖风险的模型存在疑问。最后，在操作人员位置测量的VLF电场和磁场符合世界各地制定的场强标准和指南。
