Pathophysiology of cell phone radiation: oxidative stress and carcinogenesis with focus on male reproductive system

The health effects of radiofrequency electromagnetic waves (RF-EMW) emitted from cell phones have been debated greatly [1,2]. Researchers initially were concerned about how microwave radiation affected human biological systems by increasing tissue temperature--in other words, its thermal effects [3]. To protect the public from excessive exposure to RF-EMW, limits were established by international organizations such as the ICNIRP (International Commission on Non Ionizing Radiation Protection) [4]. For example, the limit of radiation exposure from a mobile phone in the United States and Europe is 1.6 Watts/kg and 2.0 Watts/kg, respectively [1,4].Recent studies demonstrated microwaves emitted from the cell phone, i.e., RF-EMW do not produce thermal effect at specific absorption rate (SAR) of 1.6 Watts/Kg [5-7]. However, researchers have demonstrated that RF-EMW from commercially available cell phones have non-thermal effects [8,9]. The literature contains controversial reports on the effects of RF-EMW on, mitochondria, apoptosis pathway, heat shock proteins, free radical metabolism, cell differentiation, DNA damage and the plasma membrane [1,9-16].Among the effect of RF-EMW on various body organs, effect of RF-EMW on brain is the most researched area [17-24]. Additionally, recent studies suggest that RF-EMW emitted from cell phones can reduce the fertilizing potential of men [25]. It is important to note that many men carry their cell phones in a trouser pocket (or clipped to their belts on waist) while using a hands-free device such as Bluetooth. This technology exposes the testes to more high power density cell phone radiation than a cell phone would in the 'Stand by mode' in a trouser pocket. Due to this reason, investigating effect of RF-EMW on male fertility is also important.In this article, we review the effects of RF-EMW on free radical metabolism and carcinogenesis as well as the epidemiological, in vitro animal and in vitro human studies that have assessed th