Dosimetry for infant exposures to electronic article surveillance system: Posture, physical dimension and anatomy

Abstract

The use of electronic article surveillance (EAS) systems has become popular in many public sites. As a consequence, concern has risen about infant exposure to magnetic fields (MFs) from this kind of device. To evaluate infant exposure to MFs of an EAS system (operating at 125 kHz and 13.56 MHz), we numerically compared dosimetric results among adult, child and infant models. Results revealed that postures insignificantly influenced dosimetric results if there was a similar cross-sectional area under exposure. Although safety limits are unlikely to be exceeded, the infant has higher SAR values for brain and central nervous system tissues compared with adult (1.5x at 125 kHz and 112x at 13.56 MHz), which deserve further investigation. Infant's specific anatomy (e.g., non-proportionally large head and high fat content) did not induce higher SAR values. The numerical models developed in the study (stroller and postured infant models) could be freely used for nonprofit academic research.

Exposure assessment of one-year-old child to 3G tablet in uplink mode and to 3G femtocell in downlink mode using polynomial chaos decomposition

“…A numerical model of a one year-old child developed by Li et al (2014) has been used to perform the simulations. Further details about that infant model can be found in Li et al (2015). The mass of the model is 9.90 kg, the height is 74 cm and it is segmented in 27 tissues.…”

“…Only in 2014, Li and colleagues developed a 12 month-old Chinese infant model from magnetic resonance (MR) images including 27 tissues. This numerical model of an infant was then used in Li et al (2015) and in Li and Wu (2015), to assess the exposure to several RF sources by means of deterministic dosimetry. In detail, in the first study, Li and colleagues investigated the exposure to (i) a transverse electromagnetic plane-wave RF source, in the range of frequencies 20 MHz-3 GHz, (ii) a dipole simulating 3G and 4G wireless communications in the frequency bands 2.1, 2.4 and 2.53 GHz placed close to the infant head and (iii) a PC tablet operating in data-transfer mode in the same range of frequencies as the dipole and positioned in front of the eye.…”

Measurement and Exposure Assessment of Intermediate Frequency Magnetic Fields From Electronic Article Surveillance (EAS) Gates in Libraries

“…Assessment of the induced electric field in the body is needed to ensure conformity with the basic restrictions in the proximity to the gatepost. Some dosimetric research has been performed on EM-EAS gates ( 17 , 18 ), but they used the simulated magnetic fields generated by a model of a gatepost consisting of two coils. In addition, they did not take the elliptical polarization of the magnetic field due to the phase difference of coil currents into account.…”