A Thermodynamic Perspective on the Interaction of Radio Frequency Radiation with Living Tissue

The existence of biological effects of radio frequency (RF) radiation on living tissue is well established, including also effects which are athermal, that is not caused by plain warming. Still the exact mechanisms of interaction between the RF radiation and the living tissue are mostly unknown. In this work a thermodynamic perspective relevant to some aspects of those yet unknown mechanisms is presented. This perspective reveals that living tissue under RF radiation should not be assumed to be in thermal equilibrium since it is governed by two temperatures: The ambient temperature of its surroundings and a vastly higher temperature TR which is assigned by certain criteria to the RF radiation. The criteria presented here to determine the radiation temperature TR are not unique and other approaches may lead to different temperature values, however TR as presented here has an interesting physical significance. The possible relevance of this approach to the interaction mechanisms is presented; specifically some molecules in the living tissue may acquire much more energy than the one associated with the ambient temperature and biological effects may occur.