Comparative SAR assessment in adults and children exposed to electromagnetic fields of radio frequency devices

Exposure to radio frequency electromagnetic fields has raised scientific and public concern regarding possible adverse effects to people exposed to such radiation. At cellular mobile communication frequencies, the most important parameter used to assess human exposure to electromagnetic fields is SAR (Specific Absorption Rate). This paper will firstly address two exposure scenarios related to adult exposure to GSM electromagnetic fields : Human exposure to 900 MHz GSM base station electromagnetic fields, whereby with EMR-300 is measured field strength on different points located meters away from base station antenna. Using SAR prediction formula we have calculated induced SAR values for people located near base station antenna. The obtained results are compared with maximum permissible levels and basic restrictions of international safety standards. Human exposure to mobile phone GSM electromagnetic fields, whereby with a software (FDTD code) have simulated human head exposure to mobile phone radiation and have calculated Spatial Peak SAR over 1 g and 10 g of human body biological tissues. Secondly, in order to investigate comparison of radio frequency energy absorption by head of children and adults, the Spatial Peak SAR over 1g and 10g is calculated for: uniformly down-scaled adult head with increased dielectrical parameters compared to adult ones and uniformly down-scaled adult head with adult dielectrial parameters. SAR results are presented graphically and tabulary while comparative assessment is given in order to emphasize influence of head size and change of dielectrical parameters on radio frequency energy absorption by human tissues, and give possible answer whether children should be treated as special group regarding radio frequency exposure. Even not an all inclusive approach is considered, obtained results indicate that SAM may be considered conservative for assessment of children exposure compliance to radio frequency electromagnetic fields. Key-Words: Radio frequency, GSM, SAR, SAM, base station antenna, field strength, mobile phone, child, dielectrical properties.