American Journal of Applied Sciences 5 (10): 1344-1347, 2008 ISSN 1546-9239 © 2008 Science Publications Corresponding Author: K.W. Tam, Wireless Communication Laboratory, Faculty of Science and Technology, University of Macau, Av. Padre Tomas Pereira, Taipa, Macao SAR, China Tel: (853) 3974496 Fax: (853) 28838314 1344 Electromagnetic Assessment on Human Safety of Mobile Communication Base Stations at University of Macau K.H. Chiang and K.W. Tam Wireless Communication Laboratory, Faculty of Science and Technology, University of Macau, Av. Padre Tomas Pereira, Taipa, Macao SAR, China Abstract: Assessment of the electromagnetic exposure due to the mobile communication base station at University of Macau is presented by two testing scenarios. The first scenario about 20 in-situ measurements and the maximum E-field strength was 2.46 V/m that well below the threshold and compliant to the safety guideline. The second scenario investigates on the distance effect of exposure due to the base station and it is found that the field strength decays by 0.12 dB/m. Thus, low radiation level estimated at the university when compared with the measured values. Key words: Radiation safety, Specific Absorption Rate (SAR), International Commission on Non- Ionizing Radiation Protection (ICNIRP) INTRODUCTION In the past few decades, the mobile communication has been evolved from analogue system to latest digital cellular communications. In Macau where is a small city with an area of around 28 Km 2 and located 60 Km from Hong Kong, its mobile communication also evolved from GSM 900 in 1995 to GSM 1800 and CDMA in 1999 and 2006 respectively. There are totally four public digital cellular communication operators in Macau and over 635,000 subscribers registered in 2006. This rapid development has also brought the persistent public concerns about the possible adverse health effects of electromagnetic emissions from digital cellular telephone base stations. It is thus necessary to carry out the electromagnetic compatibility assessment to identify whether the level of emission due to the base stations represents a risk for human health according to the international safety guideline. In particular, there is a digital cellular base station located in the hostel area nearby the central campus of University of Macau as shown in Fig. 1a. As illustrated, the base station antenna is installed in the rooftop of hostel building Block II as in Fig. 1b and these antennas are facing the central campus building named Choi Kai Yau shown in Fig. 1c where more than 35 classrooms and 40 office rooms are allocated. The base station is generally emitting the RF power of 42 dBm and 38 dBm for GSM 900/1800 and CDMA respectively. The purpose of this work was mainly to perform in-situ a b c Fig. 1: a Base station nearby Choi Kai Yau building, (b) A base station in the roof of block II building, (c) Choi Kai Yau building in the central campus