Thermal effects of microwave radiation on biogenic magnetite particles and circuits: theoretical evaluation of cellular phone safety aspects

Microwave heating of biogenic magnetite particles in human brain tissue is evaluated theoretically using a resistive heating eddy current model. Calculations based on particle size, electrical conductivity of magnetite, and power output from cellular telephones indicate that local heating of submicron magnetite particles is insignificant in comparison with thermal background effects at present power output levels and magnetite concentrations. Specific cells (magnetocytes) containing large numbers of biogenic magnetite particles may form complex circuits leading to increased heating, although this is still insignificant. The presence of unknown quantities of superparamagnetic particles in the circuit, however, may alter these results.