No effects of short-term exposure to mobile phone electromagnetic fields on human cognitive performance: A meta-analysis
Institute of Working and Organisational Psychology, UMIT-University for Health Sciences, Medical Informatics and Technology, Linz, Austria. .Bioelectromagnetics (Impact Factor: 1.71). 02/2012; 33(2). DOI: 10.1002/bem.20697
During recent years, a large number of studies on the effects of electromagnetic fields emitted by cellular mobile phones on human cognitive performance have been carried out. However, the results have been ambiguous. We carried out the current meta-analysis in order to investigate the impact of electromagnetic fields emitted by mobile phones on human cognition. Seventeen studies were included in the meta-analysis as they fulfill several requirements such as single- or double-blind experimental study design, and documentation of means and standard deviations of dependent variables. The meta-analysis was carried out as a group comparison between exposed and non-exposed subjects. No significant effects of electromagnetic fields emitted by Global System for Mobile Communications (GSM) and Universal Mobile Telecommunications System (UMTS) mobile phones were found. Cognitive abilities seem to be neither impaired nor facilitated. Results of the meta-analysis suggest that a substantial short-term impact of high frequency electromagnetic fields emitted by mobile phones on cognitive performance can essentially be ruled out. Bioelectromagnetics. © 2011 Wiley-Liss, Inc.
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- "Exposure to radiofrequency electromagnetic field is associated with overproduction of reactive oxygen species in the brain of rat. Barth et al. reported that the cognitive abilities neither impaired nor facilitated electromagnetic fields emitted by GSM and Universal Mobile. Neither heating nor overproduction of reactive oxygen species explain the cardiac effect of mobile in this study because the subjects were exposed to short duration of electromagnetic energy (40 sec). "
ABSTRACT: Electromagnetic energy radiated from mobile phones did not show significant effect on the blood pressure, heart rate, and electrocardiographic (ECG) parameters in animals and humans. This study aimed to investigate the effect of radiofrequency of mobile phone on the electrocardiographic parameters in patients with history of ischemic heart disease, taking into consideration the gender factor. A total number of 356 participants (129 males and 227 females) were admitted in this study. They were grouped into: subjects without cardiac diseases (Group I), patients with ischemic heart disease (Group II), and patients with history of cardiac diseases not related to myocardial ischemia (Group III). Electrocardiogram was obtained from each patient when the mobile phone was placed at the belt level and over precordium in turn-off mode (baseline) and turn-on mode for 40 sec ringing. The records of ECG were electronically analyzed. Prolongation of QTc interval was significantly observed in male gender of Groups I and III (P < 0.001). Male patients of Group II showed significant QTc interval prolongation (P = 0.01) and changes in the voltage criteria (P = 0.001). These changes were not observed in female patients with ischemic heart disease. The position of mobile at the belt level or over the precordium showed effects on the heart. The radiofrequency of cell phone prolongs the QT interval in human beings and it interferes with voltage criteria of ECG records in male patients with myocardial ischemia.
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- "With rare exception , , these studies only involved brief (3–120 minute), single EMF exposure at GMS, CW, or UMTS cell phone parameters given to normal subjects. Not surprisingly, recent reviews/meta-analyses find these “acute" exposure studies to result in no significant beneficial or impairing effects on cognitive performance , . Nonetheless, several PET studies have reported that acute, single-exposure EMF treatment can affect regional cerebral blood flow ,  and increase brain glucose utilization , thus suggesting that even acute high frequency EMF treatment can affect brain neuronal activity. "
ABSTRACT: Few studies have investigated physiologic and cognitive effects of "long-term" electromagnetic field (EMF) exposure in humans or animals. Our recent studies have provided initial insight into the long-term impact of adulthood EMF exposure (GSM, pulsed/modulated, 918 MHz, 0.25-1.05 W/kg) by showing 6+ months of daily EMF treatment protects against or reverses cognitive impairment in Alzheimer's transgenic (Tg) mice, while even having cognitive benefit to normal mice. Mechanistically, EMF-induced cognitive benefits involve suppression of brain β-amyloid (Aβ) aggregation/deposition in Tg mice and brain mitochondrial enhancement in both Tg and normal mice. The present study extends this work by showing that daily EMF treatment given to very old (21-27 month) Tg mice over a 2-month period reverses their very advanced brain Aβ aggregation/deposition. These very old Tg mice and their normal littermates together showed an increase in general memory function in the Y-maze task, although not in more complex tasks. Measurement of both body and brain temperature at intervals during the 2-month EMF treatment, as well as in a separate group of Tg mice during a 12-day treatment period, revealed no appreciable increases in brain temperature (and no/slight increases in body temperature) during EMF "ON" periods. Thus, the neuropathologic/cognitive benefits of EMF treatment occur without brain hyperthermia. Finally, regional cerebral blood flow in cerebral cortex was determined to be reduced in both Tg and normal mice after 2 months of EMF treatment, most probably through cerebrovascular constriction induced by freed/disaggregated Aβ (Tg mice) and slight body hyperthermia during "ON" periods. These results demonstrate that long-term EMF treatment can provide general cognitive benefit to very old Alzheimer's Tg mice and normal mice, as well as reversal of advanced Aβ neuropathology in Tg mice without brain heating. Results further underscore the potential for EMF treatment against AD.
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ABSTRACT: The universal failure of pharmacologic interventions against Alzheimer's disease (AD) appears largely due to their inability to get into neurons and the fact that most have a single mechanism-of-action. A non-invasive, neuromodulatory approach against AD has consequently emerged: transcranial electromagnetic treatment (TEMT). In AD transgenic mice, long-term TEMT prevents and reverses both cognitive impairment and brain amyloid-β (Aβ) deposition, while TEMT even improves cognitive performance in normal mice. Three disease-modifying and inter-related mechanisms of TEMT action have been identified in the brain: 1) anti-Aβ aggregation, both intraneuronally and extracellularly; 2) mitochondrial enhancement; and 3) increased neuronal activity. Long-term TEMT appears safe in that it does not impact brain temperature or oxidative stress levels, nor does it induce any abnormal histologic/anatomic changes in the brain or peripheral tissues. Future TEMT development in both AD mice and normal mice should involve head-only treatment to discover the most efficacious set of parameters for achieving faster and even greater cognitive benefit. Given the already extensive animal work completed, translational development of TEMT could occur relatively quickly to "proof of concept" AD clinical trials. TEMT's mechanisms of action provide extraordinary therapeutic potential against other neurologic disorders/injuries, such as Parkinson's disease, traumatic brain injury, and stroke.
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