An Experimental Multi-Frequency System for Studying Dosimetry and Acute Effects on Cell and Nuclear Morphology in Rat Tissues

Abstract

Abstract-Simultaneous exposure to multiple electromagnetic signals with widely differing carrier frequencies is a reality of daily life, but its possible effects on health are unknown. In this study, we exposed rats to non-thermal levels of 900 and 2450 MHz TEM-mode radiation, applied individually or simultaneously, and we obtained estimates of 1 g mean SAR (specific absorption rate) in various tissues using a numerical model of the rat and finite-difference timedomain software. The experimental system comprised a GTEM (gigahertz TEM) chamber connected to two vector signal generators, a signal mixer and amplifier, a directional coupler, a spectrum analyzer and a power meter. Tissue sections from rats sacrificed 24 h after exposure, and from negative controls and positive controls exposed to gamma radiation, were stained with haematoxylin-eosin for evaluation of general cell morphology and with DAPI (4', 6-diamidino-2-phenylindole) for evaluation of apoptosis. Lesions, tissue destruction and apoptosis were only observed in positive controls. The results for rats exposed to either frequency, or to both simultaneously, were similar to those of unexposed negative controls. It remains to determine whether chronic exposure is similarly innocuous.

Evidence of cellular stress and caspase-3 resulting from a combined two-frequency signal in the cerebrum and cerebellum of Sprague-dawley rats

“…The apparent absence of biological effects on rat tissue morphology was inconclusive in a prior study [ 13 ] that compared biological effects of a single RF with those of two simultaneous RF signals. In contrast, the current work allowed us to experimentally determine that the biological effects of the simultaneous interaction of radiofrequencies were neither additive nor greater than the effects of applying each signal separately.…”

“…In previous work, we observed that the acute interaction of several radiofrequencies with non-thermal SAR did not increase cellular apoptosis in eight different types of tissue [ 13 ]. However, in the current work we found a significant increase in pre-apoptotic activity (see Results).…”

“…However, there are no studies that provide information about stress-induced cellular change after simultaneous exposure to several frequencies, which is the most common scenario for EMF interaction in humans. We recently carried out a study with an experimental multi-frequency model on eight different rat tissues [ 13 ]. The absence of acute tissue effects in that work failed to answer: 1) whether absorbed energy and/or biological effects are additive in tissue, and 2) if the interaction mechanism for combined frequencies is the same as that for a single frequency in live tissue.…”

Are Exposures to Multiple Frequencies the Key to Future Radiofrequency Research?

“…In these studies (not included in Table 8 ), restrained male rats were exposed at up to 0.2 W/kg in a GTEM cell, and SARs were estimated using numerical phantoms. In the first study, it was reported that single or simultaneous exposure had no effect on cellular morphology and apoptosis in eight tissues, including the brain, muscle, and testicles ( 54 ). In the second study, effects on cellular stress responses were investigated in the cerebral cortex and cerebellum ( 55 ).…”

The Influence of Human Head Model Wearing Metal-Frame Spectacles to the Changes of Sar and Antenna Gain: Simulation of Frontal Face Exposure

“…This leads to users being exposed to the RF electromagnetic radiation emitted by mobile communication equipment, such as cellular phones. Concern about possible health effects due to exposures to electromagnetic fields (EMs) has increased among the public and professionals since these communication devices have proliferated around the globe [1][2][3][4][5][6][7][8]. This concern has caused an increase in the research emphasis on analyzing the rate at which electromagnetic radiation is being absorbed by the human body [1][2][3][4][5][6][7][9][10][11][12][13][14][15][16][17].…”