Hirata A, Ito N, Fujiwara O. Influence of electromagnetic polarization on the whole-body averaged SAR in children for plane-wave exposures. Phys Med Biol. 54(4):N59-N65. January 14, 2009 Ahead of print.
The objective of this study was to determine the effects of polarization of incident electromagnetic waves on the whole body averaged specific absorption rate (WBSAR). WBSAR is a measure of basic restriction for radio-frequency (RF) whole body exposure.
In the present study, a model for WBSAR absorption for nine-month old model was developed by linearly reducing three-year-old Japanese infant model using a plane wave with both vertical polarization (VP) and the horizontal polarization (HP). The major concern in this study was on the WBSAR in children for general public.
The results showed that WBSAR for exposures with vertical polarization is smaller than horizontal polarization for frequencies above 2 GHZ. The results of WBSAR were confirmed using vertical polarization and horizontal polarization for three-year-old, five-year-old, and seven-year-old child models. The reason for this difference is attributed to the component of the surface area perpendicular to the electric field as evidenced by the results of the study which show that SAR averaged over the trunk is similar for the different polarizations and the difference was observed at the top of the head, the shoulders, and the instep.
The results of the current study were compatible with previous studies showing that the dominant factor influencing the WBSAR in this frequency region is the surface area of the body model.