قياس مستويات التعرض الاشعاعي لأشعة التردد الراديوي المنبعثة من المصادر المختلفة في البيئة الفلسطينية
علاء الدين محمد صبح هماش
Alaa aldin Mohammad Subeh Hammash
This study presents the results of exposure levels to radio frequency radiation emitted from various electromagnetic sources in the Palestinian environment. These sources include FM and TV broadcasting stations as well as mobile phone base stations. A database of sources officially registered at the Palestinian Ministry of Telecommunications and IT, has been established. All relevant technical data has been provided by this ministry and in case of mobile phone base stations by the Palestine Cellular Communications Ltd (Jawwal). This database includes information about 550 mobile phone base stations, 37 TV and 56 FM broadcasting stations. Locations and types of these sources are illustrated on a West Bank map using GIS techniques. Power density and electric field strength are measured in about 35 locations distributed over the West bank area. These locations include centers of the main cities, highly populated areas as well as rural areas. Also a 24 hours activity level is investigated for a mobile phone base station to determine the maximum activity level for this kind of radio frequency radiation sources. All measurements were conducted at a height of 1.7 m above ground level using two spectrum analyzers (BK 2650 and Narda SRM 3000), with different antennas capable of collecting radio frequency signals in the frequency bandwidth from 75 MHz to 3 GHz. Contributions from all relevant radio frequency sources to the total exposure are evaluated in the city centers and found to be 66% from FM radio, 2% for TV broadcasting and 32% from mobile phone base stations. This indicated that the main source of exposure in our environment is FM radio broadcasting and not mobile phone base station (which is the main source of public concern). The average value of power density resulted from FM radio broadcasting in all locations is 0.148 μW/cm2, from TV broadcasting is 0.007 μW/cm2 and from mobile phone base station is 0.089 μW/cm2. The maximum power density measured at any location was 2.66μW/cm2, and is resulted from FM radio broadcasting at the city center of Ramallah. This maximum measured power density is about 1.3% of the maximum permissible level (200 μW/cm2) recommended by the International Commission on Non-Ionizing Radiation Protection for the general public.
الدراسات البيئية , Environmental Studies