Comparison and evaluation of electromagnetic absorption characteristics in realistic human head models of adult and children for 900-MHz mobile telephones

The controversy on the dosimetry in children´s heads for mobile telephones is still inconsistent. Gandhi´s group [1996, 2002] reported a considerable increase of the spatial peak specific absorption rate (SAR) in children´s heads, while Kuster´s group [1998] claimed that there was not a significant difference in the SAR between children and adults. In this paper, based on Japanese children´s statistical data on external shapes of heads, we developed two kinds of children´s models from a Japanese adult head model. Using the children´s head models, we calculated the local peak SAR under the same conditions as those previously employed by Gandhi´s and Kuster´s groups. Compared to the local peak SAR in the adult head model, we found a considerable increase in the children´s heads when we fixed the output power of the monopole-type antenna, but no significant differences when we fixed the effective current of the dipole-type antenna. This finding suggests that the contradictory conclusions drawn by the above two groups may be due to the different conditions in their numerical peak SAR calculations.