Vistnes A I, Gjötterud K
Department of Physics, University of Oslo, Oslo, Norway.
Bioelectromagnetics. 2001 Apr;22(3):200-4. doi: 10.1002/bem.39.
When evaluating possible mechanisms by which low frequency electromagnetic fields may have a biological effect, arguments based on photon energy have often been used in a misleading way. For visible light the concept of photons has proved to be very useful in explaining experimental findings. However, the concept of photons cannot be used without major modifications in describing phenomena related to near field problems at power frequency (50 or 60 Hz) electric and magnetic fields. For this regime, the photon description is very complex. A very high number of highly coherent photons must be used in a quantum electrodynamic description of low frequency electromagnetic field phenomena. Thus, one-photon interaction descriptions must be replaced by multiple-photon interaction formalism. However, at low frequencies, a classical electromagnetic field description is far more useful than quantum electrodynamics. There is in principle no difference in how much energy an electron can pick up from a low frequency electric field as compared to from a high frequency photon. Thus, the total gain in energy is not limited to the energy carried by a single photon, which is E = hv, where h is Planck's constant and (v) is the frequency of the radiation. However, the time scale of the primary event in a mechanism of action is very different for ionizing radiation compared to power line frequency fields. The advice is to consider the time scale given by the inverse of the frequency of the fields, rather than photon energy, when one use physics as a guidance in evaluating possible mechanisms for biological effects from low frequency electromagnetic fields.
在评估低频电磁场可能产生生物效应的潜在机制时，基于光子能量的论点常常被误导性地使用。对于可见光而言，光子概念已被证明在解释实验结果方面非常有用。然而，在描述与工频（50或60赫兹）电场和磁场相关的近场问题现象时，若不进行重大修正，光子概念就无法使用。对于这种情况，光子描述非常复杂。在对低频电磁场现象进行量子电动力学描述时，必须使用大量高度相干的光子。因此，单光子相互作用描述必须被多光子相互作用形式所取代。然而，在低频时，经典电磁场描述远比量子电动力学有用。原则上，电子从低频电场中获取的能量与从高频光子中获取的能量并无差异。因此，总能量增益并不局限于单个光子所携带的能量E = hv，其中h是普朗克常数，v是辐射频率。然而，与电力线频率场相比，电离辐射作用机制中主要事件的时间尺度有很大不同。建议在以物理学为指导评估低频电磁场生物效应的可能机制时，考虑由场频率的倒数给出的时间尺度，而非光子能量。
