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M. Bédja, I. M., M. Souques, J. Lambrozo, L. Le Brusquet, G. Fleury, A. Azoulay, F. Deschamps and A. Carlsberg. (2010). Methodology of a study on the French population exposure to 50 Hz magnetic fields. Radiat Prot Dosimetry, 142(2-4), 146–152.
Abstract: The characterisation of population exposure to a 50-Hz magnetic field (MF) is important for assessing health effects of electromagnetic fields. With the aim of estimating and characterising the exposure of the French population to 50-Hz MFs, two representative samples of the population were made. A random selection method based on the distribution of households in different regions of France was used. The samples were carried out starting from a random polling of telephone numbers of households (listed, unlisted fixed phones and cell phones only). A total of 95 362 telephone numbers were dialed to have 2148 volunteers (1060 children and 1088 adults). They all agreed to carrying an EMDEX II meter, measuring and recording MFs, and to filling out a timetable for a 24-hour period. In this article, the methodology of the sample selection and the collection of all necessary information for the realisation of this study are presented.
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Kaune WT, Z. L. E. (). Assessing historical exposures of children to power-frequency magnetic fields. J Expo Anal Environ Epidemiol., 1994(4), 149–70.
Abstract: One risk factor for human cancer currently being studied is residential exposure to power-frequency magnetic fields. A key problem in such research is how best to use contemporaneous measurements to assess past magnetic-field exposures. The main goal of the research presented in this paper was to examine the effectiveness of various surrogate measures in predicting historical exposures and to determine if residential power consumptions and the loads served by neighborhood electric networks could be used to improve the accuracy of such predictions. Residential magnetic-field data were collected during 24-h periods in the spring of 1990 and, again, in the winter of 1990-1991 for 35 children living in Western Massachusetts and Northern California. Measurements included spot magnetic fields in rooms occupied by subjects for an average of one or more hours per day, 24-h recordings at locations selected to emphasize ground-current and power-line fields, personal exposures, wire codes, residential power consumptions, and loads served by neighborhood electric networks. The geometric means of time-weighted-averaged (TWA) room spot magnetic fields measured during earlier and later visits to each home were 0.052 microT and 0.060 microT, respectively. Geometric-mean personal exposures for these visits were 0.084 microT and 0.111 microT and were significantly larger. Wertheimer-Leeper wire codes were associated with exposure. These codes, TWA spot fields, and the 24-h averages of the magnetic-field recordings taken to emphasize power-line contributions were about equally effective in explaining between-home variability in personal exposures measured eight months in the past or future. In contrast, personal exposure measurements were ineffective surrogates for past or future exposure. The study yielded little evidence suggesting that residential power consumption or neighborhood electric power flow are helpful in explaining temporal changes in personal exposure.
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Christ A, K. W., Hahn EG, Honegger K, Zefferer M, Neufeld E, Rascher W, Janka R, Bautz W, Chen J, Kiefer B, Schmitt P, Hollenbach HP, Shen J, Oberle M, Szczerba D, Kam A, Guag JW, Kuster N. (2010). The Virtual Family--development of surface-based anatomical models of two adults and two children for dosimetric simulations. Phys Med Biol., 55(23-38).
Abstract: The objective of this study was to develop anatomically correct whole body human models of an adult male (34 years old), an adult female (26 years old) and two children (an 11-year-old girl and a six-year-old boy) for the optimized evaluation of electromagnetic exposure. These four models are referred to as the Virtual Family. They are based on high resolution magnetic resonance (MR) images of healthy volunteers. More than 80 different tissue types were distinguished during the segmentation. To improve the accuracy and the effectiveness of the segmentation, a novel semi-automated tool was used to analyze and segment the data. All tissues and organs were reconstructed as three-dimensional (3D) unstructured triangulated surface objects, yielding high precision images of individual features of the body. This greatly enhances the meshing flexibility and the accuracy with respect to thin tissue layers and small organs in comparison with the traditional voxel-based representation of anatomical models. Conformal computational techniques were also applied. The techniques and tools developed in this study can be used to more effectively develop future models and further improve the accuracy of the models for various applications. For research purposes, the four models are provided for free to the scientific community.
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A Peyman, C. G., E H Grant, G Vermeeren and L Martens. (2009). Variation of the dielectric properties of tissues with age: the effect on the values of SAR in children when exposed to walkie–talkie devices. Phys Med Biol., 54, 227–241.
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.
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Peyman A, G. C. (2010). Cole-Cole parameters for the dielectric properties of porcine tissues as a function of age at microwave frequencies. Phys Med Biol., 55(413-419).
Abstract: We have applied the Cole–Cole expression to the dielectric properties of tissues in the frequency range 0.4–10 GHz. The data underpinning the model relate to pig tissue as a function of age. Altogether, we provide the Cole–Cole parameters for 14 tissue types at three developmental stages.
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