The Effects of Pulsed 860 MHz Radiofrequency Radiation on the Promotion of Neurogenic Tumors in Rats

Article · June 2006with25 Reads
DOI: 10.1667/RR3551.1 · Source: PubMed
Abstract
In a previous study, this laboratory reported a statistically nonsignificant trend for shortened latency of ethylnitrosourea (ENU)-induced brain tumors in Sprague-Dawley rats exposed to an 860 MHz pulsed radiofrequency (RF) signal. The present study was designed to investigate further any promoting effect of the pulsed RF signal on latency and other characteristics of neurogenic tumors in the progeny of pregnant rats treated with 6.25 or 10 mg/kg ENU. The resulting 1080 offspring were randomized equally by number, sex and ENU dose into pulsed RF, sham and cage control groups. The rats were exposed to the pulsed RF signal 6 h per day 5 days per week; the sham-exposed group was similarly confined for the same periods, and the cage controls were housed in standard cages. An essentially equal number of rats from each group were killed humanely every 30 days between the ages of 171 and 325 days; 32 rats died and 225 rats were killed when they were moribund. Postmortem examinations on the 1080 rats revealed 38 spinal cord tumors, 191 spinal nerve tumors, 232 cranial nerve tumors, and 823 brain tumors. A methodical study of the tumor characteristics disclosed no evidence that exposure to the pulsed RF signal affected the incidence, malignancy, volume, multiplicity, latency or fatality associated with any kind of neurogenic tumor.
    • These full-body exposure studies have determined that such radiofrequency treatment does not initiate, nor does it promote, any type of cancer investigated. With RF treatment at these parameters extending from 5 months to life-long, four studies found no evidence for an induction of brain tumors [24][25][26][27], and another study reported no ability of such RF treatment to promote brain tumor growth initiated by a chemical carcinogen [28]. Similarly, 900 MHz RF treatment extending from several weeks to life-long did not promote chemically-induced breast cancer [29][30][31], nor did it promote UV radiation-induced skin cancer [32].
    [Show abstract] [Hide abstract] ABSTRACT: We have demonstrated in multiple studies that daily, long-term electromagnetic field (EMF) treatment in the ultra-high frequency range not only protects Alzheimer's disease (AD) transgenic mice from cognitive impairment, but also reverses such impairment in aged AD mice. Moreover, these beneficial cognitive effects appear to be through direct actions on the AD process. Based on a large array of pre-clinical data, we have initiated a pilot clinical trial to determine the safety and efficacy of EMF treatment to mild-moderate AD subjects. Since it is important to establish the safety of this new neuromodulatory approach, the main purpose of this review is to provide a comprehensive assessment of evidence supporting the safety of EMFs, particularly through transcranial electromagnetic treatment (TEMT). In addition to our own pre-clinical studies, a rich variety of both animal and cell culture studies performed by others have underscored the anticipated safety of TEMT in clinical AD trials. Moreover, numerous clinical studies have determined that short- or long-term human exposure to EMFs similar to those to be provided clinically by TEMT do not have deleterious effects on general health, cognitive function, or a variety of physiologic measures-to the contrary, beneficial effects on brain function/activity have been reported. Importantly, such EMF exposure has not been shown to increase the risk of any type of cancer in human epidemiologic studies, as well as animal and cell culture studies. In view of all the above, clinical trials of safety/efficacy with TEMT to AD subjects are clearly warranted and now in progress.
    Full-text · Article · May 2016
    • The article however elected to subjugate the rats to an exposure of the 860 MHz as mentioned previously [18] . The effects of this difference in radio frequency have the potential to be highly significant, and the article was keen to point out that other publications have called for future research to address this concern [18]. As confident as each study was in their respective results, the study by Frei et al. thought it important to point out that there existed limitations within its study.
    [Show abstract] [Hide abstract] ABSTRACT: Background: The association between cellular phones and brain tumors is a question that is frequently asked of the medical and scientific community. The prevalence of cell phone use and the significant morbidity and mortality of brain tumors contribute to this pairing. Cell phones are known to emit radio frequency energy in the form of both ionizing and non-ionizing radiation. Ionizing radiation is known to be within X-rays, which do have an association with cancer. Objective: To assess if the use of the cell phone has an association with brain tumors. Methods: The searches performed through PubMed were conducted to find studies that sought to provide evidence as to whether or not increased cell phone exposure contributed to the development of brain tumors. Also searched for was increased regional metabolism of the brain with the use of the cell phone switched in the on position. Studies were restricted to being published during or after the year 2000 and presented in the English language. Results: The studies largely support the conclusion that cell phone usage does not lead to the development of brain cancer. Studies employed different strategies, such as the prospective cohort and case-control studies to reach this conclusion. Both studies failed to show statistically significant evidence that cell phones were associated with brain tumors of the central nervous system. Conclusions: Questions raised by crossover studies demonstrating increased regional brain glucose metabolism continue to remain largely unanswered by current research and remain a starting point for future research. The prevalence of the issue strengthens its position among others as a matter that the medical community must continue to address to meet the needs of an increasingly exposed patient population. The overall hypothesis that cell phone usage does not lead to the development of brain tumors was supported.
    Full-text · Article · Jan 2016
    • They continued the study by investigating the promoting effect of the pulsed RF signal on latency and other characteristics of neuro-genic tumours in the progeny of pregnant rats given ENU at whole-body concentrations 6.25 or 10 mg/kg. A study of the tumour characteristics in 1283 tumours of the 1080 offspring disclosed no evidence that exposure to the pulsed RF signal affected the incidence, malignancy, volume, multiplicity, latency or fatality associated with any kind of neuro-genic tumour (Zook & Simmens 2006). La Regina et al. (2003) investigated the effect of chronic exposure to 835.62 MHz FDMA or 847.74 MHz CDMA radiofrequency radiation on the incidence of spontaneous tumours in rats (La Regina, et al. 2003).
    [Show abstract] [Hide abstract] ABSTRACT: ABSTRACT In 1996 there was no convincing laboratory evidence that EMFs used in wireless communication could cause tumour promotion at non-thermal exposure levels. Therefore we then performed a study of the effects from exposure to such electromagnetic fields in the rat brain glioma model we were using in our research for brain tumour therapy. By stereotaxic technique rat glioma cells (RG2 or N32) were injected into the head of the right caudate nucleus in 154 pairs of Fischer 344 rats in both exposed and matched controls. Starting on day 5 after inoculation, the animals were exposed for 7 hours a day, 5 days a week during 2 - 3 weeks. Rats of both sexes were exposed to electromagnetic fields in the microwaves frequency range 915 MHz both as continuous waves (1 W), and as pulse-modulated at 4, 8, 16 and 217 Hz in 0.57 ms long pulses and 50 Hz in 6.67 ms pulses, all with a maximum power amplitude of 2 W per pulse. The animals were kept un-anaesthetized in well-ventilated TEM cells during 7 hours a day for 5 days a week for 2-3 weeks. Their matched controls were kept in identical TEM cells without EMF exposure. At the end of the exposure period the rat brains were examined histopathologically. The tumour size was measured with a calliper and the volume estimated as an ellipsoid. Our study of the 154 matched pairs of rats did not show any significant difference in tumour volume between animals exposed to 915 MHz microwaves, and those not exposed. Thus our results did not support that daily exposure to EMF promotes tumour growth when given from the fifth day after the start of tumour growth in the rat brain until the sacrifice of the animal 16 days later. In the present review our results published 1997 have been re-evaluated in terms of SAR dependence of tumour volume observed ratio (exposed / control). We thus surprisingly found that the shape of tumour volume-OR versus SAR response was of bath-tube pattern, similar to that found in our parallel studies of albumin leakage through the blood-brain barrier. Since the SAR varies between most other animal studies reviewed and human epidemiological studies this SAR dependence might explain the controversy in rendering the results. Keywords: Brain tumour, RG2, N32, Fischer rats, electromagnetic fields 915 MHz, CW, pulse modulated: 4, 8, 16, 50, 217 Hz , SAR.
    Full-text · Article · Mar 2014 · International Journal of Radiation Biology
    • They continued the study by investigating the promoting effect of the pulsed RF signal on latency and other characteristics of neuro-genic tumours in the progeny of pregnant rats given ENU at whole-body concentrations 6.25 or 10 mg/kg. A study of the tumour characteristics in 1283 tumours of the 1080 offspring disclosed no evidence that exposure to the pulsed RF signal affected the incidence, malignancy, volume, multiplicity, latency or fatality associated with any kind of neuro-genic tumour (Zook & Simmens 2006). La Regina et al. (2003) investigated the effect of chronic exposure to 835.62 MHz FDMA or 847.74 MHz CDMA radiofrequency radiation on the incidence of spontaneous tumours in rats (La Regina, et al. 2003).
    File · Data · Mar 2014 · International Journal of Radiation Biology
    • On the other hand, immobilization causes stress that might affect the outcome of the experiments. The effects of stress resulting from restraint and related daily handling has been seen in many studies as lower body weight among the sham-exposed (restrained) animals than among the cage-control (unrestrained) animals (Heikkinen et al., 2003; Oberto et al., 2007; Shirai et al., 2007; Smith et al., 2007; Yu et al., 2006; Zook and Simmens, 2006 ). In many of these studies, tumor incidence has also been lower and survival higher in the sham-exposed (restrained) group than in the cage-control (unrestrained) group, which may be related to the observations that reduced energy intake inhibits the development of tumors (Imaida et al., 2001; Keenan et al., 1996; Klurfeld et al., 1991; Sinha et al., 1988).
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, the authors present a comprehensive review of animal studies on carcinogenicity of radiofrequency (RF) electromagnetic fields. The rapid increase in mobile telephony has resulted in concerns regarding possible heath effects from the low-level but increasingly ubiquitous exposure to RF fields. The possible carcinogenicity of RF fields has been investigated in a number of experimental models including classical rodent bioassays, studies using genetically predisposed animals, cocarcinogenicity studies, and studies evaluating effects on the development of tumors from transplanted tumor cells. Overall, the results of these studies are rather consistent and indicate no carcinogenic effects at exposure levels relevant to human exposure from mobile phones. This finding is consistent with the results of the majority of epidemiological studies on mobile phone users, and suggests that RF field exposure below the present guidelines is not likely to cause cancer.
    Full-text · Article · Sep 2011
    • There was a report on the increase in tumors ipsilateral to the side of the head on which subjects recalled phone use (Hardell et al. 2002), but this was not substantiated by other studies (Muscat et al. 2000). RF exposure to rat heads did not affect the incidence, malignancy, volume, multiplicity, latency, or fatality associated with any kind of neurogenic tumor (Zook and Simmens 2006). Alteration of the cognitive and physiological function of brains after exposure to mobile phone frequency RF has been reported by several electrophysiological studies (Curcio et al. 2005).
    [Show abstract] [Hide abstract] ABSTRACT: Radiofrequency (RF) exposure at the frequency of mobile phones has been reported not to induce cellular damage in in vitro and in vivo models. We chose HEI-OC1 immortalized mouse auditory hair cells to characterize the cellular response to 1763 MHz RF exposure, because auditory cells could be exposed to mobile phone frequencies. Cells were exposed to 1763 MHz RF at a 20 W/kg specific absorption rate (SAR) in a code division multiple access (CDMA) exposure chamber for 24 and 48 h to check for changes in cell cycle, DNA damage, stress response, and gene expression. Neither of cell cycle changes nor DNA damage was detected in RF-exposed cells. The expression of heat shock proteins (HSP) and the phosphorylation of mitogen-activated protein kinases (MAPK) did not change, either. We tried to identify any alteration in gene expression using microarrays. Using the Applied Biosystems 1700 full genome expression mouse microarray, we found that only 29 genes (0.09% of total genes examined) were changed by more than 1.5-fold on RF exposure. From these results, we could not find any evidence of the induction of cellular responses, including cell cycle distribution, DNA damage, stress response and gene expression, after 1763 MHz RF exposure at an SAR of 20 W/kg in HEI-OC1 auditory hair cells.
    Full-text · Article · Dec 2008
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Conference Paper
January 2011
    Conference code: 87845, Export Date: 22 January 2013, Source: Scopus, Language of Original Document: English, Correspondence Address: Usman, A.D.; Centre of Excellence on Lightning Protection (CELP), Faculty of Engineering, Universiti Putra Malaysia, UPM, Serdang, Selangor 43400, Malaysia, References: Hamadoun, T., Strong global mobile cellular growth across all regions (2010) International... [Show full abstract]
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    March 2014
      ABSTRACT In 1996 there was no convincing laboratory evidence that EMFs used in wireless communication could cause tumour promotion at non-thermal exposure levels. Therefore we then performed a study of the effects from exposure to such electromagnetic fields in the rat brain glioma model we were using in our research for brain tumour therapy. By stereotaxic technique rat glioma cells (RG2 or... [Show full abstract]
      Article
      October 2007
        Radiofrequency (RF) radiation at the frequency of mobile phones has been not reported to induce cellular responses in in vitro and in vivo models. We exposed HEI-OC1, conditionally-immortalized mouse auditory cells, to RF radiation to characterize cellular responses to 1763 MHz RF radiation. While we could not detect any differences upon RF exposure, whole-genome expression profiling might... [Show full abstract]
        Article
        July 2008 · Experimental and Molecular Medicine · Impact Factor: 3.45
          Even though there is no direct evidence to prove the cellular and molecular changes induced by radiofrequency (RF) radiation itself, we cannot completely exclude the possibility of any biological effect of mobile phone frequency radiation. We established a carousel-type exposure chamber for 849 MHz or 1763 MHz of mobile phone RF radiation to expose RF to the heads of C57BL mice. In this... [Show full abstract]
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