This paper presents the distribution of electric field inside a human head as well as around the electromagnetic field source, i.e. the mobile phone. Specific Absorption Rate (SAR), which is obtained inside a human head and the thermal effect due to exposure to electric field from mobile phone was presented. For this research two different models of human head have been used. In the first case electromagnetic parameters of biological tissues of human head were modeled with a volumetric interpolation function that estimates the characteristics of a given tissue inside the human head while in the second case model with layers was used. The layers represent human head parts (skin, fat tissue, muscles, the skull, and the brain). The parts of the human head are based on their electromagnetic properties (conductivity, electric permittivity, and magnetic permeability). In order to obtain the electric field distribution for different cross-sections, the numerical calculation based on the Finite Integration Technique (FIT) and Finite Element Method (FEM) was performed.

Background/Aim. A mobile phone is a source of electromagnetic radiation located close to the head and consequently its intense use may cause harmful effects particularly in younger population. The aim of this study was to investigate the influence of electromagnetic field of the mobile phone on the pituitary gland of the child. Methods. In order to obtain the more accurate results for this research 3D realistic model of child's head whose size corresponds to an average child (7 years old) was created. Electric field distribution in child head model and values of Specific Absorption Rate (SAR) at the region of pituitary gland were determined. This study was performed for the frequencies of 900 MHz, 1800 MHz, and 2100 MHz, as the most commonly used in mobile communications. The special attention was dedicated to the values of the electric field and the values of the SAR in the pituitary gland. For all frequencies over 10 g and 1 g of tissue average SAR was calculated. The electric field distribution and values of average SAR for 10 g and 1 g trough the model of child's head were obtained by the using numerical calculation based on the Finite Integration Technique (FIT). Results. The largest value of electric field in the region of the pituitary gland was at the frequency of 900 MHz, as a consequence of the highest penetration depth. Lower values of the electric field in the region of the pituitary gland were at frequencies of 1,800 MHz and 2,100 MHz. The SAR in the pituitary gland decreased as the frequency increased as a direct consequence of lower penetration depth. Conclusion. The electric field strength from a mobile phone is higher than the value specified by standards for the maximum allowable exposure limits. The high values of the electric field are not only in the vicinity of a mobile phone but also in tissues and organs of the human head. Particular attention should be paid to the exposure of children to radiation of mobile phones. Smaller dimensions of children?s head and smaller thickness of tissues and organs have as a consequence greater penetration of electromagnetic waves.

Purpose: The purpose of this paper is to determine the impact of human age on the distribution of electric field and absorbed energy that originates from a mobile phone. Design/methodology/approach: This research was performed for frequencies of 900, 1800 and 2100 MHz, which are used in a mobile communication system. To obtain the most accurate results, 3 D realistic model of the child’s head has been created whereby the dimensions of this model correspond to the dimensions of a seven-year-old child. Distribution of the electric field and specific absorption rate (SAR) through the child’s head was obtained by numerical analysis based on the finite integration technique. Findings: The results discover that amount of absorbed energy is greater in the surface layers of the child’s head model when the electromagnetic (EM) characteristics of tissues are adjusted for the child. This deviation corresponds to different EM characteristics of biological tissues and organs of an adult person compared to a child. Research limitations/implications: The study deals with penetrated electrical field and absorbed EM field energy. There is space for further studies of other EM field effects (e.g. thermal effects). Practical implications: The analysis of obtained results leads to idea that mobile phones and devices aimed for children using should be modified to provide SAR values inside prescribed standards. Social implications: The obtained results are foundation for future research on influence of EM fields of mobile devices on human health. Originality/value: The proposed procedure offers the model for accurate estimation and quality analysis of SAR and EM field distribution inside child head tissue.

The frequent use of mobile phones in children causes public concern over possible harmful effects of electromagnetic radiation. In this paper, a numerical analysis based on the finite element method has been performed in order to assess the absorbed EM energy in the child head originating from a mobile phone at 1.8 GHz and 2.1 GHz. A realistic head model composed of specially shaped parts with different EM characteristics corresponding to a seven-year-old has been developed for that purpose. The results of the SAR (Specific Absorption Rate) distribution for the particular cross-sections and directions are presented and discussed.

A comparison between results obtained using different calculation methods, simulations and experimental results for different grounding electrodes of same dimension and characteristic is carried out in the paper. The procedures include Method of Moments (MoM), Point Matching Method (PMM) and standard equations for the design of a grounding system. Calculation for the grounding grid system, vertical and horizontal rod electrode was performed by using point matching method. Obtained values are compared with simulation results and with experimental results. Simulations where performed by COMSOL program package application. The potential distribution and resistances are determined.