RESUMEN
A radiofrequency (RF) electromagnetic radiation safety assessment had been carried out at public access points within the compound of a teaching hospital. The frequency band investigated ranged from 87.5 MHz to 2.6 GHz. Eighty-eight measurements were made using a spectrum analyser coupled with a log-periodic antenna. The objective was to determine the level and nature of RF fields within the immediate premise of the facility where patients of health conditions are kept and treated. Results complied with the International Commission of Non-Ionising Radiation (ICNIRP) guidelines. The values of the resolved electric field at four spatial heights ranged from 1.00 ± 0.144 mV/m to 1.174 ± 0.169 V/m. Power densities varied from 2.65 ± 0.38 nWm-2 to 3.66 ± 0.528 mWm-2. There were relatively high contributions from frequencies above 900 MHz compared with contributions from lower frequency bands.
Asunto(s)
Campos Electromagnéticos , Exposición a Riesgos Ambientales/análisis , Hospitales de Enseñanza , Monitoreo de Radiación/métodos , Ghana , HumanosRESUMEN
Heightened awareness of the ever-expanding use of radiofrequency (RF) techniques and technology has led to mounting concerns from the general public and the scientific community regarding the possible health effects that may arise as a consequence of exposure to RF radiations and has drawn the attention of many researchers the world over. A survey of the RF electromagnetic radiation at public access points in the vicinity of 20 frequency-modulated (FM) radio stations has been made in Accra, Ghana. The fundamental object was to determine the levels of RF fields from FM broadcast antennae within 10-200 m radius about the foot of the FM base station and at a height of 1.5 m above the ground at selected locations. A spectrum analyser and a bi-conical antenna element sensitive and effective within the frequency band of 30-300 MHz were used. Results obtained indicated that the levels of electric field strength ranged from 5.4E-04 V m(-1) at FM station 'O' to 7.4E-08 V m(-1) at FM station 'D'. At a transmission frequency range of 88-108 MHz, the variation of power densities is from 2.5E-10 to 1.5E-17 Wm(-2). These values are very low and are far below the reference level set by the International Commission on Non-Ionizing Radiation Protection and therefore do not pose any known hazard to the inhabitants of Accra, Ghana. The electric field levels presented in this work are comparable with those reported from epidemiological studies conducted elsewhere.