Variation of the dielectric properties of tissues with age: the effect on the values of SAR in children when exposed to walkie–talkie devices

TLDR

At microwave frequencies, the observed variations are mainly due to the reduction in the water content of tissues as an animal ages. In vitro dielectric properties of ageing porcine tissues were measured from 50 MHz to 20 GHz, uncertainties assessed, and the data were used to compute SAR values for 3‑ and 7‑year‑old children exposed to walkie‑talkie RF. Ageing reduces permittivity and conductivity in most tissues, yet SAR values for 3‑ and 7‑year‑old children are not significantly different from adults.

Abstract

In vitro dielectric properties of ageing porcine tissues were measured in the frequency range of 50 MHz–20 GHz, and the total combined uncertainties of the measurements were assessed. The results show statistically significant reduction with age in both permittivity and conductivity of 10 out of 15 measured tissues. At microwave frequencies, the observed variations are mainly due to the reduction in the water content of tissues as an animal ages. The results obtained were then used to calculate the SAR values in children of age 3 and 7 years when they are exposed to RF induced by walkie–talkie devices. No significant differences between the SAR values for the children of either age or for adults were observed.