The Model of Equivalent Radiofrequency Electromagnetic Field Exposure for Biological Effect Assessment

Electromagnetic field biological effects of experimental animal exposure studies are the main part of scientific based hygienic regulations and safety standards development. This aspect sets the problem of comparing the different exposure conditions for various biological objects as their biological equivalence. This problem is relevant for radiofrequency electromagnetic exposure assessment coincidence in near and far field also. The aim of study was to develop the approach that allows improved interpretation of experimental animal study data for possible radiofrequency electromagnetic field human health effects prediction, as well as transfer between near, and far field exposure conditions. It is rational to use the electromagnetic energy absorption and time factor (exposure time) as the basic criteria for biological equivalence assessment of various exposure conditions. Energy absorption is the base significant parameter for biological effects research. Biologically equivalent time as exposure factor takes into account the differences of biological species sensitivity to radiofrequency electromagnetic field exposure. The proposed model is based on statement that initial animal exposure is equivalent to predicted human exposure by specific biological effect if they provide the same SAR value of animal and human and affects the biological object during appropriate equivalent time. The developed model was used to compare the experimental exposure conditions in near field with power density values standardized for far field in 0.3-3.0 GHz frequency range. The experimental male rats near field exposure was simulated to calculate the SAR values in nervous and blood systems which correspond to observed biological effects. The predicted human far field exposure was simulated to obtain the power density level provides the similar SAR values. Biologically equivalent exposure time for rat and human was used also to calculate and compare the final equivalent electromagnetic exposure loads for both biological objects.