Biological Effects of Electromagnetic Fields—Mechanisms for the Effects of Pulsed Microwave Radiation on Protein Conformation

doi:10.1006/jtbi.2000.2123

Journal of Theoretical Biology

Volume 206, Issue 2, 21 September 2000, Pages 291-298

https://doi.org/10.1006/jtbi.2000.2123 Get rights and content

Abstract

Microwave exposure under “athermal” conditions occurs when no temperature rise can be measured by conventional thermometry. The existence of biological effects arising from the athermal exposure is still controversial, partly because of a lack of the linear dose response relation. We propose a model in which pulsed microwave radiation causes a triggering of the heat shock or stress response by altering the conformation of proteins through a transient heating of the protein and its close environment. We support this by modelling using the heat diffusion equation and show that pulsed exposure even when athermal can lead to transient temperature excursions outside the normal range. We propose that the power window phenomenon in which biological effects are observed at low power levels may be caused by an incomplete triggering of the heat shock response.

References (27)

I.L. CAMERON et al.
A mechanistic view of the non-ideal osmotic and motional behavior of intracellular water
Cell Biol. Intl.
(1997)
C. DANIELLS et al.
Transgenic nematodes as biomonitors of microwave-induced stress
Mut. Res.
(1998)
M. DONNELLAN et al.
Effects of exposure to electromagnetic radiation at 835 MHz on growth, morphology and secretory characteristics of a mast cell analogue, RBL-2H3
Cell Biol. Intl.
(1997)
P.W. FRENCH et al.
Electromagnetic radiation at 835 MHz changes the morphology and inhibits proliferation of a human astrocytoma cell line
Bioelectrochem. Bioenerg.
(1997)
N. PEREZ et al.
Increased synthesis and accumulation of heat shock 70 proteins in Alzheimer's disease
Brain Res. Mol. Brain Res.
(1991)
M. PORCELLI et al.
Non-thermal effects of microwaves on proteins: thermophilic enzymes as model system
FEBS Lett.
(1997)
S. BLACKMAN et al.
Design and Analysis of Modern Tracking Systems
(1999)
C.V. BYUS et al.
Alterations in protein kinase activity following exposure of cultured human lymphocytes to modulated microwave fields
Bioelectromagnetics
(1984)
S.K. CHATTOPADHYAY et al.
Reverse-micelle model: pH, electromagnetic field and inhibitor enzyme interaction
Cancer Biochem. Biophys.
(1997)
E.L. CHRONISTER et al.
Vibrational coherence decay and population relaxation in weakly disordered ionic molecular crystals
J. Phys. Chem.
(1991)

A.H. FREY et al.

Psychophysical data on the RF hearing effect

7th Annual Microwave Power Symposium, International Microwave Power Institute, 25, New York, USA

(1972)

J.D. GIBSON

The Mobile Communications Handbook

(1996)

T. HA et al.

Single-molecule fluorescence spectroscopy of enzyme conformational dynamics and cleavage mechanism

Proc. Natl. Acad. Sci. U.S.A.

(1999)

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For example, skin, bone, blood, muscles, epithelial or neural tissues differently absorb radiofrequency (Cleveland et al., 1997; Habash, 2008). Electromagnetic radiation (including microwaves) can change plasma membrane structure and functionality (Robertson et al., 2006; Neumann et al., 1982), cause DNA damage (Lai and Singh, 1996; Blank and Goodman, 1999), activate/deactivate cell enzymes (De Iuliis et al., 2009; Panagopoulos, 2011; Simon et al., 2000), alter conformations of proteins (Kesari et al., 2011), and calcium-potassium ions efflux (Laurence et al., 2000; Ha, 2001). Heating and mechanical strain can also make protein and amino acid crystals to generate electrical charge, physiological significance of which is still unknown.
Mobile phones have become an indispensable utility to modern society, with international use increasing dramatically each year. The GSM signal operates at 900 MHz, 1800 MHz and 2250 MHz, may potentially cause harm to human tissue. Yet there is no in silico model to aid design these devices to protect from causing potential thermal effect. Here we present a model of sources of heating in a mobile phone device with experimental verification during the phone call. We have developed this mobile phone thermal model using first principles on COMSOL® Multiphysics modelling platform to simulate heating effect in human auricle region due to mobile phone use. In particular, our model considered both radiative and non-radiative heating from components such as the lithium ion battery, CPU circuitry and the antenna. The model showed the distribution and effect of the heating effect due to mobile phone use and considered impact of battery discharge rate, battery capacity, battery cathode material, biological tissue distance, antenna radio-wave frequency and intensity. Furthermore, the lithium ion battery heating was validated during experiments using temperature sensors with an excellent agreement between simulated and experimental data (<1% variation). Mobile phone heating during a typical call has also been simulated and compared with experimental infrared thermographic imaging. Importantly, we found that 1800 MHz frequency of data transmission showed the highest temperature increase in the fat/water phantom used in this simulation. We also successfully compared heating distribution in human auricle region during mobile phone use with clinical thermographic images with reasonable qualitative and quantitative agreements. In summary, our model provides a foundation to conceive thermal and other physical effects caused by mobile phone use and allow for the understanding of potential negative health effects thus supporting and promoting personalized and preventive medicine using thermography.
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Regular ArticleBiological Effects of Electromagnetic Fields—Mechanisms for the Effects of Pulsed Microwave Radiation on Protein Conformation

Abstract

Cell Biol. Intl.

Mut. Res.

Cell Biol. Intl.

Bioelectrochem. Bioenerg.

Brain Res. Mol. Brain Res.

FEBS Lett.

Design and Analysis of Modern Tracking Systems

Alterations in protein kinase activity following exposure of cultured human lymphocytes to modulated microwave fields

Bioelectromagnetics

Reverse-micelle model: pH, electromagnetic field and inhibitor enzyme interaction

Cancer Biochem. Biophys.

Vibrational coherence decay and population relaxation in weakly disordered ionic molecular crystals

J. Phys. Chem.

Psychophysical data on the RF hearing effect

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The Mobile Communications Handbook

Single-molecule fluorescence spectroscopy of enzyme conformational dynamics and cleavage mechanism

Proc. Natl. Acad. Sci. U.S.A.

Regular Article
Biological Effects of Electromagnetic Fields—Mechanisms for the Effects of Pulsed Microwave Radiation on Protein Conformation