Abstract:
RF radiation exposure from antennas mounted on rooftop mobile phone base stations have become a serious issue in recent years due to the rapidly developing technologies in wireless telecommunication. The heightening numbers of base station and their closeness to the general public has led to possible health concerns as a result of exposure to RF radiations. The primary objective of this study was to assess the level of RF radiation emitted from roof top mobile phone base station antennas and compare the measured results with the guidelines set by International Commission on Non-ionization Radiation. The maximum and minimum average power density measured from the rooftop sites inside buildings were 2.46x10-2 and 1.68x10-3 W/m2 respectively whereas that for outside buildings at the same rooftop site was also 7.44x10-5 and 3.35x10-3 W/m2 respectively. Public exposure quotient also ranged between 3.74x10-10 to 1.31x10-07 inside buildings whilst that for outside varied between 7.44x10-10 to 1.65x10-06. Occupational exposure quotient inside buildings varied between 1.66x10-11 to 2.11x10-09 whereas that for outside ranged from 3.31x10-09 to 3.30x10-07 all at the rooftop site. The results obtained for a typical tower base station also indicated that the maximum and minimum average power density was 4.57x10-1W/m2 and 7.13x10-3 W/m2 respectively. The public exposure quotient varied between 1.58x10-09 to 1.01x10-07 whilst that for occupational exposure quotient ranged between 3.17x10-10 to 2.03x10-08. The values of power densities levels inside buildings at rooftop sites are low compared to that of tower sites. This could be due to high attenuation caused by thick concrete walls and ceilings. The results obtained were found to be in compliance with ICNIRP and FCC guidance levels of 4.5 W/m2 and 6 W/m2 respectively.
