Currents Induced in Human Bodies During Radiofrequency Exposure Near a Cellular Phone Base Station

Abstract

Currents induced in human feet near a cellular phone base station were calculated by the finite-difference time-domain method and measured by a parallel plate meter at 1,869 MHz. From simulation results and measurement data, it is found that the theory of finite-difference time-domain method agrees well with the experiment. It is also found that the maximum foot currents of 20.73 and 18.51 mA were obtained by measurements and calculations when a human stands barefoot at a distance of 10 m from the cellular phone base station, respectively. From measurements and calculations, the foot currents are reduced by a factor of about 0.72–0.91 and 0.8 when the condition is changed from standing barefoot to wearing shoes, respectively. Layer currents distributed in the human body are also obtained by the finite-difference time-domain method. It is found that the highest layer currents distributed in the human body occur in the area of the chest. From the layer current profiles, it is also found that the maximum induced body current density is below the excitation threshold level of 1 mA/cm2. The impact of clothes on the induced currents is also presented. It is found that there is only a little difference in the magnitude of current distributions between the human model with and without clothes.