Early in 1993 there was a health scare related to the use of cellular telephones. A law suit, filed by a man in Florida, claimed that the use of cellular phones exacerbated his wife's brain cancer causing her death earlier than would have occured if she had not used the phones. Cellular carriers scrambled to gather data to support the position that cellular phones are harmless. In short order a list of journal articles was released by the cellular industry. The following is a review of 14 of these articles. Pacific Knowledge has done no actual research in this area. This was only an attempt to turn complex biological research into a form where people in the telecommunications industry would understand it. This is why information such as carrier frequency and power are seperated for clarification. ----------------- Overview of the Articles Reviewed The experimentation done on physiological effects of electromagnetic radiation as presented in these articles was carried out by a small number of researchers using primarily non-human tissue. Of the fourteen articles reviewed, five of the articles deal with Calcium-Ion efflux (outflow) from brain tissue. Experiments were done on different animals. Two articles deal with rats, two with chicks and one with cats. The two on rats were authored in 1981 and 1982 by the same people. The two on chicks were written in 1980 by the same group. The one on cats was written in 1982 by Adey, Bawin and Lawrence. One of these authors, Ross Adey, along with Robert Lundak, authored T-Lymphocyte suppression in 1983 and the Alteration of Protein Kinase in 1984. The work of Shelton and Merritt on rats in 1981 was based largely on the work of Bawin and Adey from 1975 through 1978. This work was on Calcium efflux in the 147 and 450 MHz ranges. Shelton and Merritt tried in the 1GHz range. They noted no calcium efflux from rat brains in that frequency, modulated and using an array of power levels. In 1982 Shelton and Merritt tried again adding Albert Chamness to the team. They tried at 1GHz and also at the 2.45 GHz range. They noted no significant difference in the outflow of calcium from rat neural tissue between the irradiated and the control (non-irradiated) group. In this article, Adey was cited for his work with "windows" for effective power density and modulation frequency. In 1982 Adey, Bawin and Lawrence tested the efflux (outflow) of calcium in a cat's brain. They found it to be similar to that found in chick brains. They also studied behavioral patterns in an awake cat during irradiation. They noted a rise in CO2 in the breathing pattern. Significance of 2450MHz This is the frequency used by microwave ovens, and the frequency proposed for microwave transfer of solar electric energy from outer space. It is also near the resonant frequency of mice (in case you are concerned). Significance of 450MHz and 147MHz This is the frequency used by police, fire etc. Much of the early work was done at these frequencies. Therefore, later work, trying to repeat or do work based on earlier work was done at the same frequencies. ----------------- Induction of Calcium-Ion Efflux From Brain Tissue by Radiofrequency Radiation:Effect of Sample Number and Modulation Frequency on the Power-Density Window Bioelectromagnetics 1:35-43 (1980) C.F. Blackman, S.G. Benane, J.A. Elder, D.E. House, J.A. Lampe, and J.M. Faulk Carrier Frequency: 147 MHz Carrier Modulation: 16 and 9 Hz Power: 0.83mW/cm2 Subject Animal: Chicks (Gallus domesticus) Replicates and extends previous work showing changes in calcium- ion binding to brain tissue. Answers the questions: 1)does the width of the power density window depend on the number of brain samples exposed simultaneously in our system? and 2) does the frequency of modulation affect the location or width of this window? The "window" did indeed grow larger with an increase in sample quantities. The results of modulation at 9Hz were the same as for 16Hz. This paper supports the idea that a select range of modulation frequencies of a 147MHz carrier do cause a change in the flow of calcium from brain tissue in a test tube. Both the mechanism for this occurance and what the consequences for the living animal are yet to be determined according to this article. ----------------- Calcium-Ion Efflux From Brain Tissue: Power-Density Versus International Field-Intensity Dependences at 50-MHz RF Radiation Bioelectromagnetics 1:277-283 (1980) C.F.Blackman, S.G.Benane, W.T.Joines, M.A.Hollis, and D.E.House Health Effects Research Laboratory, U.S.Environmental Protection Agency, Research Triangle Park, North Carolina Carrier Frequency: 50MHz Carrier Modulation: 9-16Hz sinusoidal modulation Power: 1.44 to 1.67 mW/cm2 & 3.64 mW/cm2 Subject Animal: Chicks Found to produce changes in calcium-ion efflux from chick brains. The previous study shows that power densities of a 147 MHz carrier wave, modulated between 9 and 16 Hz can enhance the efflux of calcium ions from chick-brain tissue exposed in vitro. (test tube) In this experiment it shows that positive findings are associated with 3 power densities: 1.44, 1.67 and 3.64mw/cm2, while there was no effect at power densities of 0.37, 0.72, 2.17 or 4.32mW/cm2 This paper supports the idea of a power density "window", where only very specific power densities will effect any change in the flow of calcium from brain tissue. Their experiment was identical to one they had performed previously at the 147MHz carrier frequency with similar windowing results, except at different power densities. The significance of the modulation frequency is that this is a frequency detected in the live animals brain through the use of EEGs (electroencephalograms). This paper supports the idea that RF does have affects on brain tissue, but in a very narrow set of circumstances. ----------------- Attempts to Alter 45Ca2+ Binding to Brain Tissue with Pulse- Modulated Microwave Energy Bioelectromagnetics 3:475-478 (1982) James H. Merritt, Wesley W. Shelton, and Albert F. Chamness Carrier Frequencies: 1GHz and 2.45 GHz Modulation and Power: 17 combinations of power density and pulse repetition rates Subject Animal: Rat Brain tissue This article differs from the first two in that this experiment tests calcium efflux (outflow) from rat brains instead of chick brains. Also, these experiments tested both brains exposed in a test tube and brains exposed while the rat was still alive. The live rats were injected with the calcium. Another difference in this experiment and the previous is that the carrier was pulse modulated (square wave) instead of amplitude modulated (sine wave). Lastly, the carrier frequency is significantly different. This experiment is different in enough ways to say that it has little comparitive value to the first two experiments listed here. The net result of these experiments were that there was no significant difference in the binding of calcium in rat brains that have or have not been irradiated with microwaves. ----------------- In Vitro Study of Microwave Effects on Calcium Efflux in Rat Brain Tissue Bioelectromagnetics 2:161-167 (1981) W.W.Shelton, Jr., and J.H.Merritt Department of Electrical and Computer Engineering, Florida Institute of Technology, Melbourne (W.W.S.), and USAF School of Aerospace Medicine, Brooks Air Force Base, Texas (J.H.M.) Carrier Frequency: 1 GHz frequency Carrier Modulation: 16Hz Modulated at 32Hz at 1.0 or 2.0mW/cm2 average power density Power: 0.5, 1.0, 2.0 and 15mW/cm2 Results were that radiation conditions used did not alter calcium efflux in rat brain tissue. This experiment differed from the 1st two rat experiments because of the higher frequency carrier and the means of modulation, pulse rather than sine wave. There were other small experimental differences. These experiments were carried out in a test tube. ----------------- Effects of Weak Amplitude-Modulated Microwave Fields on Calcium Efflux from Awake Cat Cerebral Cortex Bioelectromagnetics 3:295-307 (1982) W.R. Adey, S.M. Bawin, and A.F. Lawrence Carrier Frequency: 450MHz Carrier Modulation: 16Hz Sinusoidally Modulated Power: 1 - 5mW/cm2 Subject Animal: Cat This experiment on living cats was based on the earlier experiments with calcium in chick brains that showed heightened efflux of calium after being irradiated at 147MHz modulated at 16Hz. It showed that there was a difference in calcium efflux during radiation, that also corresponded to some physiological changes (CO2 respiration). Not a lot of good for you/bad for you can be drawn from this experiment. It supports the idea of the narrow window of response. At the end of the article they draw inference to other work they are doing at the same time with regard to the effect to the immune system by this alteration in calcium binding. ----------------- Immunological Effects of Amplitude-Modulated Radio Frequency Radiation: B Lymphocyte Capping Bioelectromagnetics 4:157-165 (1983) Michel F. Sultan, Charles A.Cain, and Wayne A.F. Tompkins Carrier Frequency: 147MHz Carrier Carrier Modulation: 9, 16, and 60Hz Power: 0.11 to 48 mW/cm2 Subject Animal: Exposed ICR Swiss Mouse Spleens Exposure 30 Minutes This has to do with the release of Calcium ions released from brain tissue when irradiated in a narrow power band ~0.83 mW/cm2 modulated at 16Hz or within the frequencies associated with electroencephalograms. No staticstically different B Lymphocyte capping was observed between the control (no RF) and the the RF Exposed tissue This experiment is significant in that it takes a calcium dependent immune system response antigen-antibody capping and tests it in the presence of RF. This phenomenon is highly temperature sensitive. In fact, in this experiment, temperature did cause differences, but none that could be related to RF. A wide range of power and modulation frequencies were used so as not to miss the "window" described in previous experiments. The authors "indemnify" themselves at the end by saying that their results were not definitive and that more work must be done. ----------------- Assessment of the Immune Responsiveness of Mice Irradiated With Continuous Wave or Pulse-Modulated 425MHz Radio Frequency Radiation Bioelectromagnetics 3:467-470 (1982) R.J. Smialowicz, M.M. Riddle, C.M. Weil, P.L. Brugnolotti, and J.B. Kinn Carrier Frequency: 425 MHz Carrier Modulation: Both CW and 1-ms pw @250 Pulses/second Power: 78, 17.7, 5W CW and 17.7, 1.25W for pulse modulated Subject Animal: Mice This experiment looks at the difference in biological effects between pulse modulated and CW radiation. The authors stated that if such a difference were seen it would complicate the ability to set standards for humans based on power only. The result was that there was no observed difference between irradiated and non-irradiated mice, either CW or pulse modulated. ----------------- Suppression of T-Lymphocyte Cytotoxicity Following Exposure to Sinusoidally Amplitude-Modulated Fields Bioelectromagnetics 4:157-165 (1983) Daniel B. Lyle, Patricia Schechter, W. Ross Adey, and Robert L. Lundak Carrier Frequency: 450MHz Carrier Modulation: Modulated between 0 and 100 Hz Power: 1.5 mW/cm2 This paper says that the authors observed a suppression of the immune system centered around a 60Hz modulation of a 450MHz carrier. As the modulation changed either up or down, the effect decreased substantially. Even the affect at 60Hz was noted as being transient. There was complete recovery of the animals from this affect was observed 12 1/2 hours after being irradiated. It is possible that, once again, calcium efflux could be responsible for this phenomenon. The important point here is that the modulation frequency specific response is very low frequency (60Hz), and goes away above or below it. Also, complete recovery occurs with time. ----------------- Alterations in Protein Kinase Activity Following Exposure of Cultured Human Lymphocytes to Modulated Microwave Fields Bioelectromagnetics 5:341-351 (1984) Craig V. Byus, Robert L. Lundak, Ramona M. Fletcher, and W. Ross Adey Carrier Frequency: 450MHz Carrier Modulation: 3 and 100Hz Power: 1.0 mW/cm2 Subject: Human Tonsil Lymphocytes Exposure up to 60 minutes cAMP-dependent protein kinase unaffected at 16 and 60 Hz at 15, 30 and 60 minute exposures. Non-cAMP-dependent kinase activity fell to less than 50% of unexposed levels after 15 and 30 minute exposure, but returned to normal by 45 and 60 minutes. Reduced enzyme activity occured with 16, 40 and 60 Hz modulation but not at 3, 6, 80 or 100 Hz. This rapid but transient reduction in lymphocyte protein kinase activity restricted to modulation frequencies between 16 and 60 Hz and to less than 30 Minute exposure is consistent with windowing with respect to modulation frequency and exposure duration. Again, this article supports windowing of results. This paper adds the additional window of time dependency. ----------------- Effects of Microwaves and Hyperthermia on Capping of Antigen- Antibody Complexes on the surface of Normal Mouse B Lymphocytes Bioelectromagnetics 4:115-122 (1983) Michel F. Sultan, Charles A. Cain, and Wayne A.F. Tompkins Carrier Frequency: 2.45 GHz CW Power: 100mW/cm2 30 minutes This article supports the earlier work that stated that unmodulated carriers would not produce biological results. This article differs in the use of a higher frequency and relatively higher power. ----------------- Accelerated Development of Spontaneous and Benzopyrene-Induced skin Cancer in Mice Exposed to 2450MHz Microwave Radiation Stanislaw Szmigielski, Andrzej Szudzinski, Andrzej Pietraszek, Marian Bielec, Marek, Janiak, and Jolanta K. Wrembel Bioelectromagnetics 3:179-191 (1982) Carrier Frequency: 2450MHz Power: 15mW/cm2, 5mW/cm2 This experiment, important because of recent law suits, states that mice, either treated so that they would get cancer, or bred to have a high incidence of cancer, got tumors quicker when irradiated. These mice were irradiated for two hours a day for up to 6 months. As expected, the mice irradiated at a power of 15mW got tumors sooner than the ones at 5mW. Mice stressed by confinement tend to get tumors quicker than mice living in an unbound environment. Mice irradiated at 5mW got tumors at about the same rate/time as mice not irradiated and stressed by confinement. Even though this article definitely states that long term exposure to microwave radiation "may be recognized as the potential carcinogenic risk factor", it also goes into more detail about the differences between mice and men (sorry). Mice approach whole body resonanace near the carrier frequency. The maximal absorption by a normal man at this frequency would be less by two orders of magnitude (less by a lot). The human body's resonant frequency is between 60 and 70Hz. Even at that frequency (60 to 70Hz) man's absorption would be 20% of that of the mouse at its resonant frequency. It goes on to say that the mouse study has little value in determining the risk factor for humans. ----------------- In Vitro Microwave Effects on Human Neutrophil Precursor Cells (CFU-C) Bioelectromagnetics 2:203-215 (1981) Mark J. Ottenbreit, James C. Lin, Susumu Inoue, and Ward D Peterson, Jr Carrier Frequency: 2450 MHz CW Power: 31 - 1000 mW/cm2 Subject: Human Marrow Cells Duration 15 min. The importance of this paper is that even though there was a reduction in colonies of cells, these reductions did not happen until power levels reached at least 500mW. There was no reduction in neutrophil colony number on days 6-7 or 12-14 in cells exposed at 31 or 62 mW/cm2, but as the power density was increased to 1000 mW/cm2 there was a reduction in colony number of microwave irradiated cells compared with the sham irradiated (Control group) cells. The microwave interaction with the human neutrophil colony-forming cells was apparently not related to temperature rise, or to the state of cell cycle, and was irreversible. ----------------- Immunologic and Hematopoietic Alterations by 2,450-MHz Electromagnetic Radiation Bioelectromagnetics 1:77-87 (1980) Andrew Ta-Fu Huang and Nelda G.Mold Division of Hemotology and Oncology, Department of Medicine, Duke University Medical Center, Durham, North Carolina Carrier Frequency: 2450Mhz Power: 5 - 30 mW/cm2 Subject Animal: Mice Period 1 -17 days This article shows that suppression of the immune system in mice occurs. But, it is a complex interaction between different parts of the immune system. One part of the immune system, macrophages, will suppress another part of the immune system, lymphocytes. But, eventually the microwaves stimulate the lymphocytes directly. The study states that lymphocyte function (the ability to kill tumor cells) was not decreased by the influence of microwave radiation over a ten day period. Of course "...no definite conclusions can be drawn from these studies." ----------------- Guidlines on Limits of Exposure to Radiofrequency Electromagnetic Fields in the Frequency Range From 100kHz to 300GHz Health Physics Vol. 54, No. 1(January), pp. 115-123, 1988 International Non-Ionizing Radiation Committee of the International Radiation Protection Association According to Table 2 General public exposure limits to radiofrequency electromagnetic fields: Using the Equivalent plane wave power density f/2000 where f=frequency For 900MHz (cellular frequency)the limit would be would be 0.45mW/cm2 This is about the only useful bit of information in this article. ----------------- Summary The significance of these articles, written over a decade ago, in their relation to the safety of cellular phones is suspect. Work in this area did not cease 10 years ago. A significant number of publications, especially in Bioelectromagnetics, have been published since that time. The number of articles related to microwave or rf energy and its biological effects number in the hundreds. Most of the work that has been published, as in the case of these articles I have reviewed is in the 147MHz, 450MHz and 2450MHz frequency ranges. These are the frequencies associated with public safety radio, microwave ovens and the proposed transfer of solar electric energy from outer space. The articles, with the exception of one, came from the same journal and from a small number of investigators. About half of the articles had to do with calcium. This is the chemical that is most important in nerve communication and in binding sites for the immune system. The result of this work largely stated that there is a very narrow "window" in which there is any effect from rf radiation. Essentially, unmodulated carrier frequencies had no effect. Carriers modulated at very low frequencies, 9 to 100Hz had varying effects on the subject animals. These animals included cats, rats and chicks. The above studies support the fact that there is little harm from the effects of radiation associated with cellular phones. They did this by supporting the fact that the window of response is very narrow, is caused by low frequency sine waves only and that it took a great deal of exposure (relative to man) to cause these effects. The articles stressed that much more work had to be done before inferrence to the health of man could be drawn. None of the work was done in the frequency range, or power levels related to cellular phones. ------------------------------------------------------------------------------- Help support MindWare. 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