Sergio Mancini

A radio-frequency system for in vivo pilot experiments aimed at the studies on biological effects of electromagnetic fields

An exposure system consisting of two long transversal electromagnetic (TEM) cells, operating at a frequency of 900 MHz, is presented and discussed. The set-up allows simultaneous exposure of a significant number of animals (up to 12 mice per cell) in a blind way to a uniform plane wave at a frequency of 900 MHz, for investigating possible biological effects of exposure to electromagnetic fields produced by wireless communication systems. A heating/refrigerating system has also been designed for maintaining comfortable environmental conditions within the TEM cells during experiments. An accurate dosimetric study has been performed both numerically and by means of direct measurements on phantoms and living mice. The results have shown that good homogeneity of exposure and adequate power efficiency, in terms of whole-body specific absorption rate (SAR) per 1 W of input power, are achievable for the biological target.

DOSIMETRY OF A SET-UP FOR THE EXPOSURE OF NEWBORN MICE TO 2.45-GHZ WIFI FREQUENCIES

This work describes the dosimetry of a two waveguide cell system designed to expose newborn mice to electromagnetic fields associated with wireless fidelity signals in the frequency band of 2.45 GHz. The dosimetric characterisation of the exposure system was performed both numerically and experimentally. Specific measures were adopted with regard to the increase in both weight and size of the biological target during the exposure period. The specific absorption rate (SAR, W kg(-1)) for 1 W of input power vs. weight curve was assessed. The curve evidenced an SAR pattern varying from <1 W kg(-1) to >6 W kg(-1) during the first 5 weeks of the life of mice, with a peak resonance phenomenon at a weight around 5 g. This curve was used to set the appropriate level of input power during experimental sessions to expose the growing mice to a defined and constant dose.

Characterization of a train compartment scenario for the individual exposure assessment

Previous studies identified the train compartment as the place where people can experience the highest exposure levels to electromagnetic fields in the radiofrequency range. Thus, in this study, a possible scenario of a train compartment has been reproduced and characterized, both numerically and experimentally, in order to assess the individual exposure. A very good agreement between the electric field values measured and simulated has been found. Results indicate that the individual exposure may increase, depending on the number of active cell phones, the coverage condition, and the position inside the compartment, while remaining well below the limits imposed by the international regulations.

Experimental Calibration Procedure at 1.8 GHz of Electric Field Probes in a Slotted Waveguide

The world wide diffusion of hand held mobile devices has been focusing the attention of researchers on the energy coupling of the RF electromagnetic fields produced by this type of devices with biological systems. This kind of interaction is well described by the physical quantity SAR (Specific Absorption Rate), it is therefore worthwhile to define a measurement procedure of SAR distribution in biological samples. Moreover the necessity to base an experimental measurement on a rigorous standard procedure is a matter of primary importance particularly when different laboratories and research groups are involved in the same problems. In the case of SAR measurements electrically short probes are commonly used in order to measure the local radio frequency electric field induced in biological systems exposed to a mobile device. Hence in the global experimental procedure becomes important the problem of calibrating in a standard way the electric field probe. The goal of this work is to present a method for calibrating electric-field probes for use both in air and in tissue at the frequency range of 1.8–1.9 GHz.

Characterization of an Exposure System Operating at Frequencies of Hand Held Mobile Devices

In order to study biological effects of electromagnetic fields several kinds of exposure system have been designed depending on different frequencies and targets (Basset et al.; 1971; McRee et al. 1971; Raganella et al., 1990). Due to the necessity of increasing the biological studies at the frequency of handhold mobile devices (Marino, 1994; Marino et al., 1995) a new exposure system has been developed. The system features have been performed according with the requirements of several experimental activities of our laboratories: the investigation of biological effects in vivo and in vitro, the exposure of multiple samples, the duration of exposure from few hours to several weeks.