Numerical Evaluation of Specific Absorption Rate in Human Head and Torso for Wearable Wireless Devices in Underground Mine Scenarios

Abstract

The radiofrequency field levels may increase in confined environments, such as underground mines, due to reflections from inner boundaries (walls and arches). This study investigated the specific absorption rate (SAR) in the head and torso of a miner wearing a wireless device in underground mine scenarios. Two high-resolution voxel models were used to analyse the effects of a tunnel structure, a metal arch and a safety helmet at 2.4 GHz and 868 MHz. The results indicated that the SAR increase is modest for all simulated underground mine scenarios and was maximum in the presence of a metal arch. At 868 MHz, some observed that the SAR was greater in deep tissues of the head and torso as compared to SAR at 2.4 GHz. Also, the torso is a better site for mounting wearable devices on the body to mitigate exposure.

Evaluating radiofrequency electromagnetic field exposure in confined spaces: a systematic review of recent studies and future directions

“…Recently, Ashraf et al. conducted a pilot study that did not consider the underground mine environment’s high temperature ( 70 ) . Therefore, assessing long-term workers’ exposure to RF-EMF in high-temperature environments is essential for different occupational settings.…”

“…Ashraf et al. (42) investigated SAR for wearable dipole antennas in different underground mine scenarios at 868 and 2400 MHz ( 70 ) . The study investigated different underground mine tunnel scenarios using a concrete structure and metal steel arch.…”