RF radiation exposure levels from the Valombola base station, in the faculty of engineering and IT vicinity, Ongwediva, Namibia

Mobile telecommunication has become an indispensable part of our daily lives. The increasing demand for mobile communication services in Namibia has seen an increase in the installation of mobile base transceiver stations (MBS´s) in and around residential areas, schools and hospitals. Mobile service providers usually increase the number of base stations in an area for better signal reception, thus catering for the high demand. This situation has caused a growing health concern from the general public, especially those living in close proximity to the base stations. In Namibia, MBS radiation exposure levels are not readily available to the general public to promote consumer safety information. EMF generated by a base station changes with time because of the variation of user traffic. In this study, an EMF-839 field meter equipped with a 3-axis high frequency probe was used to measure EMF levels around the GSM 900 MHz mobile base stations located at the vicinity of the Faculty of Engineering and IT. Measurements were taken for a period of over 2 months at predefined locations in the faculty of Engineering and IT vicinity, to consider the effect of time variation and the user traffic. The measured values are time averaged over 6 minute samples, to obtain the average electric field strength value for each point of interest. An Augmented Dickey Fuller (ADF) statistical test is used to determine the stability of the measured time series at each measurement point. The results showed that all the data time series were stationary. The measurement results are analysed on a daily, weekly and monthly basis. Comparisons are made against limits set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) for EMF exposure risk assessment. The highest estimated average RMS value was found to be 1.86 V/m, which is well below the 41.25V/m at 900MHz exposure limit set by the ICNIRP for the general public.