Assessment of the role of specific absorption rate of mobile phones on the induction of microwave-induced survival adaptive responses after exposure to lethal doses of gamma radiation

Background: Whether exposure to common electromagnetic fields affects human health adversely has been a controversial issue. The main goal of this study was to assess the role of 900 MHz microwave radiations with different specific absorption rates (SARs), emitted from some widely used cell phones, on the induction of adaptive response in male Balb/c mice after receiving a lethal dose of gamma radiation. Materials and Methods: This study was conducted on 120 male Balb/c mice. The animals were divided into groups of 20 mice each (6 groups). Group one (the control group) received neither microwave radiation nor the lethal dose of gamma radiation. Group two was exposed only to the lethal dose of 8.8 Gy. The mice in group three were first exposed to low SAR 900 MHz microwave radiations emitted from a cell phone for six hours (3 hours in the morning and 3 hours in the afternoon) for 5 days and then were exposed to a lethal dose of 8.8 Gy on day six. The mice in group 4 were treated as those in group 3 but with a moderate SAR and the mice in group 5 were also treated as those in groups 3 and 4 but with a high SAR. The mice in group six were exposed only to high SAR 900 MHz microwaves. Results: All groups were monitored for 12 days and their daily mortality rates were recorded. The results showed that there was a statistically significant difference between group two (the animals exposed only to lethal dose of gamma radiation) and the groups with a pre-exposure to microwave radiations before receiving the lethal dose. Conclusion: To the best of our knowledge, this is the first study that investigates the role of SAR on the induction of microwave-induced survival adaptive response. It can be concluded that 900 MHz microwaves emitted from cell phones, regardless of their SAR can induce adaptive responses which make the animals more resistant to subsequent lethal doses of ionizing radiation. These findings also confirm our preliminary findings obtained in a previous study.