Knave B, Gamberale F, Bergström S, Birke E, Iregren A, Kolmodin-Hedman B, Wennberg A
Scand J Work Environ Health. 1979 Jun;5(2):115-25. doi: 10.5271/sjweh.2661.
In the present epidemiologic study, 53 workers with a long-term (more than five years) exposure to the electric field of 400 kV substations were examined and compared with a matched reference group of 53 nonexposed workers from the same power companies. Matching variables included age, geographic location and employment time. The aim of the study was to investigate the possibility of persistent, chronic health effects in the exposed group as a consequence of exposure. The investigation indluded the nervous system (neurasthenic symptoms, psychological tests, electroencephalography), the cardiovascular system (symptoms, blood pressure, electrocardiography), and the blood (hemoglobin, red blood cells, reticulocytes, white blood cells including differential count, thrombocytes, sedimentation rate). Fertility was also assessed. The results showed no differences between the exposed and reference groups as a consequence of the long-term exposure to the electric fields. The groups differed, however, in that the exposed group had (a) consistently better results on the psychological performance tests, (b) a fewer number of children, especially boys, and (c) somewhat higher education. The differences in test results were due to the higher education among the exposed. The difference in number of children was also thought to be related to factors other than exposure since it was found to be present already 10--15 years before the work in 400 kV substations began.
在本次流行病学研究中，对53名长期（超过五年）暴露于400 kV变电站电场的工人进行了检查，并与来自同一家电力公司的53名未暴露工人组成的匹配对照组进行了比较。匹配变量包括年龄、地理位置和工作时间。该研究的目的是调查暴露组因暴露而产生持续性慢性健康影响的可能性。调查包括神经系统（神经衰弱症状、心理测试、脑电图）、心血管系统（症状、血压、心电图）和血液（血红蛋白、红细胞、网织红细胞、白细胞包括分类计数、血小板、血沉率）。还评估了生育能力。结果显示，长期暴露于电场后，暴露组和对照组之间没有差异。然而，两组之间存在以下不同：（a）暴露组在心理表现测试中始终取得更好的成绩；（b）子女数量较少，尤其是男孩；（c）受教育程度略高。测试结果的差异是由于暴露组的教育程度较高。子女数量的差异也被认为与暴露以外的因素有关，因为在开始在400 kV变电站工作之前的10至15年就已发现这种差异。
