Dosimetric simulations of brain absorption of mobile phone radiation : the relationship between psSAR and age

Abstract

As children develop, they differ from adults in a number of important ways, including anatomy, metabolism, immune system, and the extent of myelination of the nervous system. As a consequence, equivalent exposures to radiation from mobile phones result in different doses to specific tissues in children compared with adults. Higher doses are likely to have more severe implications in the young. A young child’s skull is not only smaller and thinner than an adult’s, but also has dielectric characteristics closer to those of soft tissues, probably due to a higher water content. The young skull better matches the electromagnetic characteristics of the skin and brain. As a result, finite-difference time-domain (FDTD) simulations confirm field penetration and higher specific absorption rate (SAR) in deeper structures in the young brain. If the peak spatial SAR (psSAR) is modeled in the entire head, as current testing standards recommend, the results for adults and children are equivalent. Our anatomically based evaluations rely on FDTD simulations of different tissues within the brain and confirm that the psSAR in a child’s brain is higher than in an adult’s brain.