Speaker
Description
In the face of rapidly expanding 5G technology and an ever-increasing number of IoT devices, children today are beginning to use smartphones at younger ages, leading to heightened concerns about radio frequency electromagnetic field (RF-EMF) exposure. While conventional dosimetry evaluations often focus on worst-case conditions—such as maximum transmission power right next to the head—accurate assessments for epidemiological research require modeling realistic, everyday usage scenarios. To address this need, this study employed finite-difference time-domain (FDTD) simulations at 1.95 GHz (4G) and 3.65 GHz (5G) using numerical body models representing a six-year-old boy and a fourteen-year-old boy. Each model was assigned three seated postures that reflect common smartphone usage: holding the device vertically or horizontally in front of the face, and holding it beside the head. The simulations assumed an antenna input power of 20 dBm and calculated the 10 g localized Specific Absorption Rate (SAR). While the highest SAR values typically appeared in the left hand or arm—the regions closest to the phone—these values remained well below the 4 W/kg guideline reference level, at most only around 9% of that limit. Notably, although there was minimal difference between child and adolescent models, the 1.95 GHz scenario produced higher SAR values than the 3.65 GHz case, attributable to differences in radiated electric fields. By capturing realistic device usage and user posture, these findings help refine dosimetry models for epidemiological studies, ultimately providing more meaningful insights into potential health effects than worst-case evaluations alone.
