Basic Studies on Mechanism of Biological Effects of Extremely Low Frequency Electric Fields

利用经卫生部授权并已确认安全性的电场暴露设备，对人体暴露极低频电场时的脑电、心电、血压、周围皮温进行同步测量和分析，测量脑电并分析σ，θ，α，β节律各频谱功率的变化，进而评价觉醒水平的变化。得到的结果如下。由于电场暴露后脑干诱发电位的低频成分增加，导致脑电诱发电位幅值指数下降，当电场作用于受试者时，体毛发生振动。因此，受试者会在野外暴露时检测到振动，因此心理效应可能会影响受试者。为了验证这种效应的可能性，引入了以下实验。为了通过野外暴露来遮盖头发的振动感，并长期保持唤醒水平，在相同的实验中，给受试者提供了脉动的风和白噪声。结果表明，在电场作用下，觉醒水平呈上升趋势，暴露后恢复到原来的水平。其次，对手部皮温、脑电地形图、心电图和血压进行了分析。虽然手部皮肤温度在电场暴露前呈上升趋势，但在电场暴露后转为下降趋势，而且在电场暴露后进一步加剧了下降趋势。在心率变异性频谱分析的基础上，分析交感神经系统和副交感神经系统的活动。在电场暴露过程中和电场暴露后，副交感神经活动减弱，交感神经活动激活。

Using electric field exposure equipment that it receives the authorization of Ministry of Health and Welfare and has already confirmed of the safety, EEG, ECG, blood pressure, peripheral skin temperature in exposing ELF( Extremely Low Frequency) electric field on human body were measured simultaneously and analyzed.The EEG was measured and the variation of each spectral power of σ, θ, α, β rhythm was analyzed, and thereafter the variation of arousal level was evaluated. The result was obtained as follows. The arousal level dropped in amplitude index of the BEG analysis because of the low-frequency-component of the BEG increasing after the electric field exposure.When a electric field was exposed to a subject, the body hair was vibrating. Hence the subject would detected the vibration as a field exposure, and therefore psychological effect might affect the subject. To verify the possibility of this effect, the following experiment was introduced. To covering the sense of vibrating hair by field exposure and maintaining the arousal level long time, fluctuating wind and white noise sound were presented to the subject in the same experiments. As a result, the arousal level tended to rise under electric field exposure, and it returns in original level after the exposure.Next, hand skin temperature, BEG, ECG and blood pressure were analyzed. Although hand skin temperature was upward trend before electric field exposure, it was changed to the declining tendency during the field exposure, and it intensified the declining tendency still more after the field exposure. The activity of sympathetic and parasympathetic nerve systems were analyzed based on the spectrum analyses of heart rate variability. During and after the electric field exposure, the parasympathetic nerve activity was weakened but the sympathetic nerve activity was activated.