Energy absorption by the human body from RF and microwave emissions in Sri Lanka

This paper presents the computed Specific Absorption Rate (SAR) in the human eye using measured field strengths from RF signals radiated by FM radio, TV and mobile cellular base stations operating in the 900 MHz band, in different parts of Sri Lanka. The SAR values in the eye are well below the internationally recognized FCC standards on human exposure to RF radiation. Calculations were carried out using the Finite Difference Time Domain (FDTD) method. The estimated SAR distribution in some organs of the human body due to exposure from signals of frequencies ranging from 100 MHz to 2500 MHz, based on an incident field of strength 1 V/m, are also presented. Some of the most vital organs of the human body, the eye, the testis, the brain and the kidney, have been examined. Results indicate that in all the organs investigated except in the testis, the maximum SAR increases with increasing frequency. Among the four organs the highest SAR of value 0.308 W/kg is in the eye and it occur at the highest frequency. The SAR distribution in the eye shows that beyond 900 MHz its maximum value shifts towards the interior of the eye and at 2500 MHz it is almost at the centre of the eye. In the kidney, at low frequencies, the highest SAR is at the front layers and it gets shifted to the centre of the kidney at 900 MHz and beyond this frequency the peak SAR shifts towards the interior. SAR values inside the four vital human body organs analyzed in this paper are below FCC standards and therefore at present we are safe.