Safety assessment of electromagnetic exposure for adult and child passengers standing on the subway platform

Abstract

The objective of this work is to evaluate the safety of adult and child passengers exposed to a radio frequency (RF) source, i.e., a leaky coaxial cable (LCX) on the subway platform. An adult model, a child model, and an LCX model have been numerically designed in COMSOL Multiphysics software. The distributions of the induced electric field (E-field), specific absorption rate (SAR), magnetic field ( H-field) and the head temperature increase in adult and child passenger models were calculated at 900 MHz. The induced fields in the passengers were compared with that without screen doors. The results show that the E-field, SAR and H-field in the whole body of the child are 2.00 × 10 -2 V/m, 1.07 × 10 -7 W/kg, and 2.94 × 10 -4 A/m, respectively. The E-field, SAR and H-field in the central nervous system of the child are 1.00e × 10 -2 V/m, 2.44 × 10 -8 W/kg, and 2.41 × 10 -4 A/m, respectively. The maximum values of the E-field, SAR and H-field in the adult passenger are 1.49–2.34 times higher than those of the child. The E-field, SAR, and H-field in the passenger models without a screen door are larger than those with a screen door. The screen door has a partial shielding effect on the RF electromagnetic field. The values of the maximum temperature that increases in adult and child head tissue are 0.2114 and 0.2111℃ after waiting 6 minutes exposure, respectively. All calculated results are well below the International Commission on Non-Ionizing Radiation Protection (ICNIRP) limits for general public exposure, indicating that RF electromagnetic exposure caused by the LCX on the subway platform is not a threat to passenger’s health.

Keywords

• electromagnetic exposure
• safety assessment
• sar
• subway platform