Assessment of non-ionizing radiation from radio frequency energy emitters in the urban area of Natal City, Brazil

The massive increase of wireless communications in the world calls for responsible actions by governments in order to prevent possible health hazards. In addition to cellular towers overcrowding in urban areas, it is also important to consider other radio frequency radiations from different sources. The electric field intensity is one of the fundamental parameters to assess the exposure of human beings to Non-Ionizing Radiation (NIR). In this study, all main non-ionizing radiation sources in the urban area of Natal, Brazil (a city of about 860.000 inhabitants) were located and characterized with respect to frequency band, telecommunications service and integrated electric field strength. Measurements of far electric field intensity with frequency ranging from 30 MHz to 3 GHz were made in a survey of 140 outdoor points spread across all the 167.26 km2 area of the city. The results obtained have made it possible to draw a map of the regions of the city according to different electric field and exposure ratio (ER) intensities. In 71.4% of the sampled outdoor points, the highest exposure ratio measured were originated from TV broadcasting services, 22.1% from Transmissions Cellular Towers and  6.4% from Frequency Modulated Broadcasting.   Key words: Non-ionizing radiation, electric field intensity, TV broadcasting, radio frequency radiation, measurement of radio frequency radiation, propagation in Urban Areas, International Commission on Non-Ionizing Radiation Protection (ICNIRP).