Finite element simulation of the electromagnetic absorption in human head

Potential health risks associated with the usage of cellular phones is a debated issue. The electromagnetic waves in the radio frequency band, emitted by the cellular phone, are absorbed by the bodily tissues, particularly those in the head, resulting to heating. Standards have been set for the allowed amount of exposure in terms of specific absorption rate (SAR), which is the energy absorbed by a unit mass of tissue per unit time. The absorption rate depends on the geometry, properties and relative location of the source as well as the geometry and the electromagnetic properties of the absorbing tissue. While it is possible to determine the absorption level through experimentation, numerical simulation offers a convenient way of estimating it for actual or hypothetical configurations. While finite difference time domain (FDTD) method is the most widely used approach in the numerical simulation of such phenomena, finite element method (FEM) studies are relatively rare. The objective of this work is to establish a FEM environment to simulate the electromagnetic absorption and the resulting temperature rise associated with the tissues in the head due to cellular phone usage. The analyses have been performed using COMSOL package. The SAR value has been found to exceed the set standards if the phone transmits with a relatively high power. The resulting temperature rise has been typically small but its long term health effects are a matter of further research.