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.