Exposure of the Public to Rf Fields in Multi-Transmitter Environments

Abstract

A contributory reason for the general heightened sense of concern about RF radiations may be the announcement by the International Agency for Research on Cancer (IARC) in 2011 that mobile phone radiations are possibly carcinogenic. It may also be due to lack of reliable and accessible information and the misunderstanding that arises thereof. This research attempted to address this problem by making detailed examination of the nature and level of the RF fields in multi-transmitter environments using a log periodic RF antenna coupled to an Anritsu Spectrum analyser by a coaxial cable with a load impedance of 50 Q. The spatial average plane wave electric field strength obtained ranged from 0.9 ± 0.1 mVm-1 to 1181.8 ± 166.6 mVm'1. The maximum plane-wave electric field strength transmitted into wet skin was 0.2276 ± 0.0321 Vm’1. This value was 2.28% more than the field strength transmitted into dry skin at the same frequency and location. SAR values ranged from 24.34 ± 3.43 pW/kg to 2.10E-05 ± 2.99E-06 pW/kg. The estimated worst-case scenario maximum energy associated with the transmitted electric fields was 1850.23 ± 261.13 MJ in dry skin. The highest power density determined was 3.70 ± 0.51 mW/m2. The total exposure quotient was 0.004% of the recommended limit of unity. The levels of the electric fields in the multi-transmitter environment assessed were well within the recommended limits of ICNIRP. The SAR associated with the field strength levels transmitted into the tissues equally complied with the recommended ICNIRP limit. The results compared well with those published by Deatanyah et al. The methodology employed may be potentially applied for improved exposure assessment in multi-transmitter environments.