Computational study of electromagnetic wave induced by mobilephones on brain tissues and its biological implications

The mobile devices, mobile phones in particular, have become an integral part of today's society with billions of users worldwide. Despite much research efforts have been done over decades, possible adverse effects of radiofrequency (RF) radiation on human health are still unclear. Although some research results show that there is elevated risk of causing cancer in human brains, other studies lead to inconclusive results. One major concern is whether brain tumors will be induced by mobile phone's RF radiation and other sources of electromagnetic waves around us. The objective of this study is to develop an effective computational method to investigate and characterize the spatial distribution of RF energy absorbed by different parts of the brain, which caused by use the mobile phone in a close distance, and study its biological implications. In this thesis, we use mathematical models and computer simulation to generate 3D distributions of the specific absorption rate (SAR) induced by mobile phone use in human head models. One digital brain model is developed based on MRI scan data, and the other is an IEEE phantom for benchmark tests. A generic phone model is also developed to study interaction of RF radiation and the brains. The Finite Difference Time Domain (FDTD) method is used to solve Maxwell equations that govern the biophysical response in the brain tissues. SAR distributions due to exposure to an electromagnetic field from mobile phones are estimated based on the solution to the Maxwell equations. Using 3-D SAR distributions, which are quantitative measures of energy deposited in the brain tissues in specific locations, we may determine most susceptible (stressful) regions that may be affected by the use of cellular phones. We hypothesize that the brain cells are affected by the long-term exposure of radiation that imposes stressful conditions resulting in alteration or mutations of the DNA sequences in brain cells. Finally, biological experiments are suggested to test our hypothesis using heat shock proteins (e.g. HSP27) as biomarkers to quantify long-term EM effects.