, Volume 25, Issue 2–4, pp 187–194 | Cite as

Non-Thermal Effect of Microwave Radiation on Human Brain

  • Hiie Hinrikus
  • Maie Bachmann
  • Ruth Tomson
  • Jaanus Lass


This study focuses on an origin of interaction mechanism of microwave radiation with nervous system—quasi-thermal field effect. The microwave field can cause fluctuations and vibration of the charged particles and membranes in tissues. The hypothesis is, that this phenomenon is similar to the effect caused by Brown motion initiated by temperature and results in the same effects without rise in temperature. The electric field of 1 V/cm can introduce disturbance of the thermal equilibrium inside a cell of 10 μm radius, which is equivalent to disturbance produced by temperature rise of 1 K. The hypothesis, that microwave heating should cause an effect independent of the microwave modulation frequency, while field effect depends on modulation frequency, was examined experimentally. The 450 MHz microwave radiation, modulated at 7, 14 and 21 Hz frequencies, power density at the skin 0.16 mW/cm2, was applied. The experimental protocol consisted of two series of five cycles of the repetitive microwave exposure at fixed modulation frequencies. Relative changes in EEG theta, alpha and beta rhythms of the group of 13 healthy volunteers were analysed. Analysis of the experimental data shows that: (1) statistically significant changes in EEG rhythms depend on modulation frequency of the microwave field; (2) microwave stimulation causes an increase of the EEG energy level; (3) the effect is most intense at beta1 rhythm and higher modulation frequencies. These findings confirm the quasi-thermal origin of the effect, different from average heating.


EMF effects low-level radiation nonionizing radiation thermal effect quasi-thermal field effect EEG rhythms 


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  1. Adair, E.R., Cobb, B.L., Mylacraine, K.S. and Kelleber, S.A.: 1999, “Human Exposure to Two Radio Frequencies (450 and 2450 MHz) Similarities and Differences in Physiological Response,” Bioelectromagnetics 20(S4), 12–20.CrossRefGoogle Scholar
  2. Adair, E.R., Mylacraine, K.S. and Cobb, B.L.: 2001, “Partial Body Exposure of Human Volunteers to 2450 MHz Pulsed or CW Field Provokes Similar Thermoregulatory Responses,” Bioelectromagnetics 22, 246–259.Google Scholar
  3. Adair, R.K.: 2002, “Vibrational Resonances in Biological Systems at Microwave Frequencies,” Biophysical Journal 82, 1147–1152.CrossRefGoogle Scholar
  4. Balzano, Q. and Sheppard, A.: 2003, “RF Nonlinear Interaction in Living Cells-I: Nonequilibrium Thermodynamic Theory,” Bioelectromagnetics 24, 473–482.Google Scholar
  5. Baranski, S.Z. and Edelwejn, Z.: 1975, “Experimental Morphologic and Electroentcephalographic Studies of Microwave Effects on the Nervous System,” Annals of the New York Academy of Sciences 247, 109–117.Google Scholar
  6. Bawin, S.M., Gavalas-Medici, R.J. and Adey, W.R.: 1973, “Effects of Modulated Very High Frequency Fields on Specific Brain Rhythms in Cats,” Brain Research 58, 365–384.CrossRefGoogle Scholar
  7. Blank, M. and Goodman, R.: 1999, “Electromagnetic Fields may Act Directly on DNA,” J.Cel. Biochem. 15, 369–374.Google Scholar
  8. Borbely, A.A., Huber, R., Graf, T., Fuchs, B., Gallmann, E. and Achermann, P.: 1999, “Pulsed High-Frequency Electromagnetic Field Affects Human Sleep and Sleep Electroencephalogram,” Neuroscience Letters 275, 207–210.Google Scholar
  9. Chizhenkova, R.A.: 1988, “Slow Potentials and Spike Unit Activity of the Cerebral Cortex of Rabbits Exposed to Microwaves,” Bioelectromagnetics 9, 337–345.Google Scholar
  10. Chua, E., Gose, E., Vinas, F.C., Dujovny, M. and Star, J.: 1999, “Temperature Distribution Produced in Brain Tissue and Other Media by a Radiofrequency Hyperthermia Generator,” Stereotactic and Functional Neurosurgery 72, 22–34(DOI: 10.1159/000029669)CrossRefGoogle Scholar
  11. De Lorge, J.O. and Ezell, C.S.: 1980, “Observing Responses of Rats Exposed to 1.28 and 5.62 GHz Microwaves,” Bioelectromagnetics 1, 183–198.Google Scholar
  12. Foster, K.R., Lozano-Nieto, A., Riu, P.J. and Ely, T.S.: 1998, “Heating of Tissues by Microwaves: A Model Analysis,” Bioelectromagnetics 19(7), 420–428.CrossRefGoogle Scholar
  13. Foster, K.R. and Schwan, H.P.: 1996, “Dielectric Properties of Tissues, in Handbook of Biological Effects of Electromagnetic Fields,” in C. Polk and E. Postow (eds.), CRC Press, Boca Raton, New York, London, Tokio, pp. 25–102.Google Scholar
  14. Gajšek, P., Hurt, W.D., Ziriax, J.M. and Mason, P.A.: 2001, “Parametric Dependence of SAR on Permittivity Values in a Man Model,” IEEE Trans.Biomed. Eng. 48, 1169–1177.Google Scholar
  15. Galarreta, M. and Hestrin, S.: 1999, “A Network of Fast-Spiking Cells in the Neocortex Connected by Electrical Synapses,” Nature 412, 72–75.Google Scholar
  16. Gavalas-Medici, R.J. and Day-Magdaleno, S.R.: 1976, “Extremely Low Frequency, Weak Electric Fields Affect Schedule-Controlled Behaviour of Monkeys,” Nature 261, 256–270.CrossRefGoogle Scholar
  17. Goodman, R. and Blank, M.: 2002, “Insights into Electromagnetic Interaction Mechanisms,” J Cell Physiol 192, 16–22.CrossRefGoogle Scholar
  18. Hinrikus, H., Parts, M., Lass, J. and Tuulik, V.: 2004, “Changes in Human EEG Caused by Low-Level Modulated Microwave Stimulation,” Bioelectromagnetics, 25, 431–440.CrossRefGoogle Scholar
  19. Huber, R., Graf, T., Cote, K.A., Wittmann, L., Gallmann, E., Matter, D., Schuderer, J., Kuster, N., Borbely, A.A. and Achermann, P.: 2000, “Exposure to Pulsed High-Frequency Electromagnetic Field During Waking Affects Human Sleep EEG,” Neuroreport 11, 3321–3325.Google Scholar
  20. Hurt, D.H., Ziriax, J.M. and Mason, P.A.: 2000, “Variability in EMF Permittivity Values: Implications for SAR Calculations,” IEEE Trans.Biome. Eng. 47, 396–401.Google Scholar
  21. IEEE Standards for safety levels with respect to human exposure to radio frequency electromagnetic fields, 3 to 300 GHz. ANSI/IEEE C95.1-1999 Edition. Institute of Electrical and Electronic Engineers, Piscataway, NJ, 1999.Google Scholar
  22. Johnson, C. and Guy, A.W.: 1972, “Non-Ionizing Electromagnetic Rhythm Effects in Biological Materials and System,” Proceedings of the IEEE 60, 692–701.CrossRefGoogle Scholar
  23. Kholodov, Y.A.: 1966, The Effect of Electromagnetic and Magnetic Fields on the Central Nervous System, Nauka Press, Moscow.Google Scholar
  24. Kholodov, Y.A.: 1967, Effects of Electromagnetic and Magnetic Fields on the Central Nervous System, (NASA-NASATT, F-465) Washington, DC.Google Scholar
  25. King, R.W.P. and Smith, G.S., Antennas in matter: fundamentals, theory and application, MIT Press, Cambridge, MA.Google Scholar
  26. Lass, J., Tuulik, V., Ferenets, R., Riisalo, R. and Hinrikus, H.: 2002, “Effects of 7 Hz-Modulated 450 MHz Electromagnetic Radiation on Human Performance in Visual Memory Tasks,” Int. J. Radiat. Biol. 78, 937–944.CrossRefGoogle Scholar
  27. Leszczynski, D., Joenvääea, S., Reivinen, J. and Kuokka, R.: 2002, “Non-Thermal Activation of the hsp27/p38MAPK Stress Pathway by Mobile Phone Radiation in Human Endothelial Cells: Molecular Mechanism for Cancer- and Blood-Brain Barrier-Related Effects,” Differentiation 70, 120–129.CrossRefGoogle Scholar
  28. Liu, J., Zhou, Y.X. and Deng, Z.S.: 2002, “Sinusoidal Heating Method to Noninvasively Measure Tissue Perfusion,” IEEE Trans Biomed Eng. 49(8), 867–877.Google Scholar
  29. Lutty, G., Mcleod, D. and Johnson, M.: 2000, “Effects of High Power Microwaves on the Retina of the Rhesus Monkey,” Bioelectromagnetics 21, 439–454.Google Scholar
  30. Malmivuo, J. and Plonsey, R.: 1993, Bioelectromagnetism, Oxford University Press, New York.Google Scholar
  31. Mann, K. and Roschke, J.: 1996, 'Effects of Pulsed High-Frequency Electromagnetic Fields on Human Sleep,” Neuropsychobiology 33, 41–47.CrossRefGoogle Scholar
  32. Mitchell, C.L., Switzer, W.G. and Bronough, E.L.: 1977, “Hyperactivity and Disruption of Operant Behavior in Rats After Multiple Exposures to Microwave Exposure, Radio Sci, 12(6S), 263–271.Google Scholar
  33. Persson, B., Salford, L. and Brun, A.: 1997, “Blood-Brain Barrier Permeability in Rats Exposed to Electromagnetic Fields Used in Wireless Communicarion,” Wireless Networks, 3, 455–461.CrossRefGoogle Scholar
  34. Reiser, H., Dimpfel, W. and Schober, F.: 1995, “The Influence of Electromagnetic Fields on Human Brain Activity,” European Journal of Medical Research 1, 27–32.Google Scholar
  35. Salford, l., Brun, A., Eberhardt, J., Malmgren, L. and Persson, B.: 2003, “Nerve Cell Damage in Mammalian Brain After Exposure to Microwaves From GSM Mobile Phones,” Environmental Health Perspectives, 111(7), 881–883.CrossRefGoogle Scholar
  36. Saunders, R.D., Kowalczuk, C.I., Sienkiewicz, Z.J.: 1991, “Biological Effects of Exposure to Non-Ionising Electromagnetic Fields and Radiations: III. Radiofrequency and Microwave Radiation”. Oxon. UK: National Radiological Protection Board, Report No NRPB-R240.Google Scholar
  37. Schirmacher, A., Winters, S., Fisher, S., Goeke, J., Galla, H.J., Kullnick, I., Ringelstein, E.B. and Stogbauer, F.: 2000, “Electromagnetic Fields (1.8 GHz) Increase the Permeability to Sucrose of the Blood-Brain Barrier in Vitro,” Bioelectromagnetics 21, 338–345.CrossRefGoogle Scholar
  38. Vorobyov, V.V., Galchenko, A.A., Kukushkin, N.I. and Akoev, I.G.: 1997, “Effects of Weak Microwave Fields Amplitude Modulated at ELF on EEG of Symmetric Brain Areas in Rats,” Bioelectromagnetics 18, 293–298.CrossRefGoogle Scholar
  39. Wagner, P., Roschke, J., Mann, K., Hiller, W. and Frank, C.: 1998, “Human Sleep Under the Influence of Pulsed Radiofrequency Electromagnetic Fields: A Polysomnographic Study Using Standardized Conditions,” Bioelectromagnetics 19, 199–202.CrossRefGoogle Scholar
  40. Yablonskiy, D.A., Ackerman, J.H. and Raichle, M.E.: 2000, “Coupling Between Changes in Human Brain Temperature and Oxidative Metabolism During Prolonged Visual Stimulation,” Neurobiology 97(13), 7603–7608.Google Scholar

Copyright information

© Springer Science + Business Media, Inc. 2005

Authors and Affiliations

  • Hiie Hinrikus
    • 1
  • Maie Bachmann
    • 1
  • Ruth Tomson
    • 1
  • Jaanus Lass
    • 1
  1. 1.Biomedical Engineering CenterTallinn University of TechnologyTallinnEstonia

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