Dosimetric Assessment of Multi-Frequency Smartwatch Electromagnetic Exposure on Children’s Sensitive Organs

Abstract To assess the electromagnetic effect on the children’s sensitive organs when they using the smartwatches, this study analyzes the electromagnetic dose absorbed by the children, especially calculate the combind electromagnetic exposure, We propose a multi-frequency smartwatch antenna (GPS L1, LTE FDD band1, 2.4G Wi-Fi/Bluetooth) and construct a 6-year-old human model including ten tissues from three sensitive organs (brain, eyes, heart). The Specific Absorption Rate (SAR) distributions are simulated under speaking and listening postures at different frequencies using CST Studio Suite. Furthermore, the SAR distributions under multi-frequency combined electromagnetic exposure are evaluated to investigate the superposition effects of electromagnetic fields. The results show that, when the child uses the smartwatch for 4G communication in the listening posture, the maximum local SAR reaches 1.683 W/kg, which is nearly half of the ICNIRP exposure limit. Electromagnetic radiation in the child’s brain is mainly concentrated on the surface of the cerebrum and cerebellum, while the radiation in the eyes is mainly distributed in the outer and anterior tissues. Under combined electromagnetic exposure, the SAR values of tissues increase by 1.17 to 3.53 times compared with single-frequency conditions but remain within safety limits. Considering the long-term use of smartwatches, the potential health risks to developing children still deserve attention.