INSTITUTE OF PHYSICS PUBLISHING

PHYSICS IN MEDICINE AND BIOLOGY

Phys. Med. Biol. 49 (2004) 345­354

PII: S0031-9155(04)66623-1

Comparison of FDTD-calculated specific absorption

rate in adults and children when using a mobile phone

at 900 and 1800 MHz

M Mart´nez-Burdalo, A Mart´n, M Anguiano and R Villar

´

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i

Consejo Superior de Investigaciones Cient´ficas, Instituto de F´sica Aplicada, C/Serrano 144,

i

i

28006-Madrid, Spain

E-mail: mercedes@iec.csic.es

Received 24 July 2003, in final form 21 November 2003

Published 5 January 2004

Online at stacks.iop.org/PMB/49/345 (DOI: 10.1088/0031-9155/49/2/011)

Abstract

In this paper, the specific absorption rate (SAR) in scaled human head models

is analysed to study possible differences between SAR in the heads of adults

and children and for assessment of compliance with the international safety

guidelines, while using a mobile phone. The finite-difference time-domain

method (FDTD) has been used for calculating SAR values for models of both

children and adults, at 900 and 1800 MHz. Maximum 1 g averaged SAR

(SAR1 g) and maximum 10 g averaged SAR (SAR10 g) have been calculated in

adults and scaled head models for comparison and assessment of compliance

with ANSI/IEEE and European guidelines. Results show that peak SAR1 g and

peak SAR10 g all trend downwards with decreasing head size but as head size

decreases, the percentage of energy absorbed in the brain increases. So, higher

SAR in children's brains can be expected depending on whether the thickness

of their skulls and surrounding tissues actually depends on age. The SAR

in eyes of different sizes, as a critical organ, has also been studied and very

similar distributions for the full size and the scaled models have been obtained.

Standard limits can only be exceeded in the unpractical situation where the

antenna is located at a very short distance in front of the eye.

(Some figures in this article are in colour only in the electronic version)

1. Introduction

The development of cellular communications and, in particular, the widespread use of mobile

phones during the last few years have motivated a great social and scientific concern about

possible harmful effects of the electromagnetic radiation from these sources on the user's

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