2005 Periódico Tchê Química  
There has been a dramatic increase in the use of mobile phone technology in the last decades, with widespread benefits in many professional and private activities. In parallel with this, the concern regarding the possibility of adverse health effects due to the absorption of electromagnetic fields by humans also increased. For several years, many research groups in different countries were developing research projects on these subjects in the areas of medicine, biophysics, engineering, etc.
more » ... , the World Health Organization (WHO) has coordinate efforts including many countries to access the existing scientific evidence of harmful health effects of non ionizing radiation (NIR) emitted from different communication equipment, such as the mobile phones and their base stations, with special emphasis to the non-thermal effects. In principle, the base stations radiate more energy. However, their antennas are usually located on the top of elevated towers (or masts) and the radiated energy is mainly concentrated in the horizontal direction. Therefore people are usually far from these antennas, and also in directions reasonably apart from those of maximum radiation. Because the conventional monopole (or whip) antennas being used now in mobile phones typically show a circular radiation pattern in the horizontal plane, they may radiate substantial levels of energy in almost all directions, very close to the body and during considerable time. It is observed that when they are operated very close to the user's head (e.g., 2,5 cm or less) , most of energy is absorbed in the head tissues (such as the bone, the brain, eye, etc), and less energy is radiated to the nearest base station. This situation is undesirable since quality of communication is worse, and the Specific Absorption Rate (SAR) in the user's head and the battery drain are increased.
doi:10.52571/ptq.v2.n04.2005.agosto/1_pgs_7_29.pdf fatcat:s7ucrdbfgrfdjk6hyxz34zdany