Dosimetric Simulations of Brain Absorption of Mobile Phone Radiation–The Relationship Between psSAR and Age

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.

[1]  S. Tapert,et al.  Adolescent Brain Development and the Risk for Alcohol and Other Drug Problems , 2010, Neuropsychology Review.

[2]  J. Wiart,et al.  Analysis of RF exposure in the head tissues of children and adults , 2008, Physics in medicine and biology.

[3]  O. Gandhi,et al.  Electromagnetic absorption in the human head and neck for mobile telephones at 835 and 1900 MHz , 1996 .

[4]  K. Straif,et al.  Carcinogenicity of radiofrequency electromagnetic fields. , 2011, The Lancet. Oncology.

[5]  Kenneth R. Foster,et al.  Are Children More Exposed to Radio Frequency Energy From Mobile Phones Than Adults? , 2014, IEEE Access.

[6]  Devra Lee Davis,et al.  Exposure Limits: The underestimation of absorbed cell phone radiation, especially in children , 2012, Electromagnetic biology and medicine.

[7]  Niels Kuster,et al.  Age-dependent tissue-specific exposure of cell phone users , 2010, Physics in medicine and biology.

[8]  N. Kuster,et al.  A numerical and experimental comparison of human head phantoms for compliance testing of mobile telephone equipment , 2005, Bioelectromagnetics.

[9]  O.P. Gandhi,et al.  Inaccuracies of a plastic "pinna" SAM for SAR testing of cellular telephones against IEEE and ICNIRP safety guidelines , 2004, IEEE Transactions on Microwave Theory and Techniques.

[10]  Osamu Fujiwara,et al.  Comparison and evaluation of electromagnetic absorption characteristics in realistic human head models of adult and children for 900-MHz mobile telephones , 2003 .

[11]  M. Martínez‐Búrdalo,et al.  Comparison of FDTD-calculated specific absorption rate in adults and children when using a mobile phone at 900 and 1800 MHz. , 2004, Physics in medicine and biology.

[12]  N. Kuster,et al.  The dependence of electromagnetic energy absorption upon human head tissue composition in the frequency range of 300-3000 MHz , 2000 .

[13]  C Gabriel,et al.  Changes in the dielectric properties of rat tissue as a function of age at microwave frequencies. , 2001, Physics in medicine and biology.

[14]  O. Gandhi,et al.  Some present problems and a proposed experimental phantom for SAR compliance testing of cellular telephones at 835 and 1900 MHz. , 2002, Physics in medicine and biology.

[15]  A. Ahlbom.  Guidelines for limiting exposure to time-varying electric, magnetic, and electromagnetic fields (up to 300 GHz) , 1998 .

[16]  C. Gabriel.  Compilation of the Dielectric Properties of Body Tissues at RF and Microwave Frequencies. , 1996 .

[17]  N Lynnerup,et al.  Cranial thickness in relation to age, sex and general body build in a Danish forensic sample. , 2001, Forensic science international.

[18]  B. Persson,et al.  Microwaves from UMTS/GSM mobile phones induce long‐lasting inhibition of 53BP1/γ‐H2AX DNA repair foci in human lymphocytes , 2009, Bioelectromagnetics.

[19]  G. Bulla,et al.  Electromagnetic Absorption in the Head of Adults and Children Due to Mobile Phone Operation Close to the Head , 2006, Electromagnetic biology and medicine.

[20]  S. Margulies,et al.  Infant skull and suture properties: measurements and implications for mechanisms of pediatric brain injury. , 2000, Journal of biomechanical engineering.

[21]  R. D. Morris,et al.  Children Absorb Higher Doses of Radio Frequency Electromagnetic Radiation From Mobile Phones Than Adults , 2015, IEEE Access.

[22]  C. Gabriel,et al.  Variation of the dielectric properties of tissues with age: the effect on the values of SAR in children when exposed to walkie–talkie devices , 2009, Physics in medicine and biology.