Nonthermal mechanism of interactions between electromagnetic fields and biological systems: A calmodulin example

The possible mechanisms of interactions of electromagnetic fields (EMF) with biological systems are often discussed in bioelectromagnetics in light of thermal versus nonthermal mechanisms. This paper attempts to show the principle difference between the biophysical and engineering approaches to biological mechanisms of EMF initiated bioeffects. While biophysical approach is based on experimentally obtained data on biological responses to the applied EMF, the engineering approach strongly relies on specific absorption rate (SAR) value. With experimental data, comparing effects of low- and high-frequency electromagnetic fields, discussing modulation of radiofrequency (RF) signals, the author demonstrates the superiority of the nonthermal approach. Biological windows, resonance mechanism, and various reported biological effects of geomagnetic fields are also in favor of the nonthermal mechanisms. Finally, one potential nonthermal mechanism involving the role of calmodulin in cellular functions is shown in this paper.