Topic

Development of a practicable computational procedure for the determination of the actual exposure in complex exposure scenarios with several different RF-sources

Start

01.12.2006

End

30.11.2007

Project Management

University of Wuppertal

Objective

Increasing mobile communication in occupational and private areas of life accompanies with a rising number of different sources of high frequency electromagnetic fields, which may contribute to the population's exposure. The goal of this research project was to develop a practicable computational procedure capable of estimating the actual exposure in complex scenarios with several different RF-sources.

The project was processed within the DMF; at the same time it aimed at contributing to the work done within the „miniWatt-II“-project, funded by the German Federal Ministry of Education and Research (BMBF).

Results

A procedure was described and implemented for estimating a person’s actual exposure in terms of SAR when exposed to high frequency electromagnetic fields emitted by different sources at the same time. The procedure makes use of a modular concept in order to enable the consideration of new sources and/or other body models in the future. At present a standing and a sitting adult body model based on data provided by the Visible Human Project is available. The procedure is based on a catalogue of datasets for the dissipated power P_V within the human body in exposure scenarios with single sources. The datasets have been prepared by means of numerical computer simulations. The practicable procedure which is proposed here, does not implicate any time-consuming numerical computations because it makes use of the results stored in the catalogue. To some extent results from other DMF-projects could be used for building up the catalogue. Information on whole body exposure scenarios is contained in the catalogue as well as information on scenarios, where there is only a certain part of the body exposed to electromagnetic fields. Radiating sources may be far away, in close proximity or even in contact with the human body. Altogether, approx. 850 files with P_V data for the different scenarios have been developed which can be combined to assess numerous user-specific situations with multiple sources. As a result the procedure gives whole-body-averaged SAR-values and localized SAR_10g-values for head/trunk and limbs respectively.

The procedure is demonstrated in the final report for two different scenarios, one indoor-scenario with six RF-sources and one outdoor-scenario with seven RF-sources. The final report is available for download in portable document format (2,2 MB).

Final Report

Conclusion

The procedure proposed by this research project provides a possible way of estimating a person’s exposure (whole-body-averaged and maximum local 10 g averaged SAR) in complex scenarios with multiple RF sources radiating at the same time and hence contributing to the overall exposure. The RF-sources may e.g. transmit at different frequencies and/or operate at different distances to the person’s body. Utilizing the procedure does not require any knowledge about numerical simulations techniques nor software tools. Because of its modular concept, the procedure can be adapted or extended to take into account future exposure scenarios if necessary.