Brain SAR of average male Korean child to adult models for mobile phone exposure assessment. (5th February 2019)

• Record Type: Journal Article
• Authors: Lee, Ae-Kyoung; Park, Jin Seo; Hong, Seon-Eui; Taki, Masao; Wake, Kanako; Wiart, Joe; Choi, Hyung-Do
• Is Part Of: Physics in medicine & biology. Volume 64:Number 4(2019:Feb.)
• Publication Date: 2019-02-05
• Subjects: RF exposure -- age -- specific absorption rate -- anatomical morphology; Biophysics -- Periodicals; Medical physics -- Periodicals; 610.153
• DOI: 10.1088/1361-6560/aafcdc
• Languages: English
• ISSNs: 0031-9155

Abstract

Abstract: This paper aims to implement average head models of Korean males and investigate age-related differences in the brain for exposure from radiation from mobile phones. Four male head models composed of a total of 69 structures were developed through a statistical investigation of the anatomical morphology for the age groups of 6, 9, 15 and 20–24 years in age, which are named KR-6, KR-9, KR-15, and KR-22 herein. Three numerical bar phone models with a dual-band built-in antenna were applied to calculate the specific absorption rate (SAR) in the brain; the body lengths of models M avg and M long have the mean value and upper 5th percentile value of commercial bar phone models, respectively, with an antenna at the bottom, whereas M rev has an antenna on top of the phone body, which is the same as in M avg but rotated 180°. The cheek and tilt positions were employed for SAR simulations. As a result, a higher peak spatial-average SAR (psSAR) was observed in the brain for the child groups of KR-6 and KR-9 than for the adult groups of KR-15 and KR-22. In most configurations, the position-averaged psSAR10 g in the child brain was 62% ( M long, 835 MHz), 61% ( M avg, 835 MHz), 102% ( M long, 1850 MHz), 108% ( M avg, 1850 MHz), and 125% ( M rev, 1850 MHz) higher than in the adult brain. The higher frequency of 1850 MHz showed a wider difference in the brain psSAR between the child and adult groups owing to the shorter penetration depth. When a long phone with an antenna at the bottom operates at a higher frequency, it significantly reduces the brain exposure.