Study reveals no risk of harm from radio frequency electronic magnetic field | 24 October 2019
According to the findings of a study to measure radio frequency (RF) electronic magnetic field (EMF) radiation in Seychelles, there is no evidence which indicates that there are risks of radiation that are harmful to human health from the 25 sites explored in the study.
The measurement task, initiated by the Department of Information Communications Technology (DICT) in 2018, sought to address public concern as to the health implications of radiation exposure from base stations.
Following the tender process in November 2018, LS Telecom of South Africa was appointed to undertake the complete measurement of non-ionising electronic magnetic field (EMF) exposure at 25 identified sites in Seychelles for a sum of $120,255.93.
After having carried out the research in collaboration with local partners, the findings of the study were officially presented to local partners DICT, Cable and Wireless Seychelles Ltd, Airtel Seychelles Ltd and the Public Health Authority (PHA) by Professional Technologist of LS Telecom Vaughan Taylor who outlined the methodology employed for the measurement as well as the results.
Mr Taylor noted that the primary aim of the measurement task was to perform narrowband EMF measurements across the entire base of mobile telephony technologies presently being used in Seychelles, including 2G, 3G and 4G, that are being used by the two licensed operators, Cable and Wireless Seychelles Ltd and Airtel Ltd and the results of each measurement tabulated and compared against the International Commission for Non-Ionizing Radiation (CNIRP) public exposure limits guidelines.
Three types of quantitative indicators were employed to conduct exposure assessments around operational RF radio transmitting facilities; electric field strength, magnetic field strength and power density. For measurements around mobile phone base stations, it is acceptable for these to be done on the far field because the measurements will be performed some distance away from the radiating antenna systems.
With regards to the findings of the study, Mr Taylor noted that the electromagnetic fields generated from mobile phone base station sites are non-constant in time and vary in proportion to the traffic throughput and established connection qualities to the respective end-users.
“In off-peak hours, the generated exposure may subside to a minimal nominal value, this being only produced through permanent signalisation information by the base station and will vary in terms of the mobile telephony system or standard in question. Due to worst case considerations, the exposure at highest operational state of the site is to be determined,” Mr Taylor said.
“The maximal exposure, documented in the report therefore contains an extrapolation factor, to determine the maximal operational state of the base station,” Mr Taylor noted.
He further stated that the highest exposure levels measured were at Mont Buxton and that the report sets out remedial actions that Airtel Seychelles Ltd can employ to mitigate radiation exposure. Among the recommendation are for the present tower structure at Mont Buxton on which the antennae are installed onto, to be extended by the mobile operator by 11 metres to limit the degree of exposure on the occupants within the dwelling below the site, along with further optimisation of the antennae.
However, director general of Communications Division, Jeffery Dogley, noted that the results indicate that the radiation levels are within the set limits and pose no threat to public health.
He warned that the public should be more concerned about the use of their smart phones which are closer to their bodies than bay stations and which also expose them to radiation.
Mr Taylor also noted that part of the responsibility for the completion of the project was also to provide in-service training for employees of DICT, in which a list of topics were covered including standards for exposure limits, status of bio-electromagnetic research, field strength variations in time and space, basic measurement principles, as well as appropriate measurement techniques for FM, DAB, LTE and an outlook to 5G.
Through the training, technicians from DICT are better equipped to carry out such measurements in future.