| 1. |
- Arnetz, Bengt B., et al.
(författare)
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The Effects of 884 MHz GSM Wireless Communication Signals on Self-reported Symptoms and Sleep : An Experimental Provocation Study
- 2007
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Ingår i: PIERS online. - 1931-7360. ; 3:7, s. 1148-1150
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Tidskriftsartikel (refereegranskat)abstract
- In the current study we assessed possible effects of prolonged (3 hours) exposure to 884 MHz GSM wireless communication signals on self-reported symptoms, cognitive function, and electroencephalographically (EEG) recorded sleep. The study group consisted of 36 women and 35 men. Twenty-two women and sixteen men reported symptoms they specifically related to mobile phone use (SG). The rest of the participants reported no mobile phone-related symptoms (NG). Potential participants volunteering for the study were evaluated by physicians, including some biochemical assessments, to rule out medical conditions that could interfere with study variables of interest. Once selected, participants spent three different sessions in the laboratory. The habituation session was followed by two subsequent sessions. In these subsequent sessions, subjects were either exposed to sham exposure (sham) or 884 MHz GSM wireless communication signals for 3 hours (an average of 1.4 W/kg including periods of DTX and Non-DTX. Exposure directed to the left hemisphere). Data was collected before, during and following the exposure/sham sessions. Data collected included self-reported symptoms, including headache, cognitive function, mood, and electroencephalographic recordings. During actual exposure, as compared to sham exposure, sleep initiated one hour after exposure was affected. There was a prolonged latency to reach the first cycle of deep sleep (stage 3). The amount of stage 4 sleep was also decreased in exposed subjects. NG subjects reported more headaches during exposures vs. sham exposure. Neither group (SG and NG) was able to detect the true exposure status more frequently than by chance alone. The study indicates that during laboratory exposure to 884 MHz wireless signals, components of sleep, believed to be important for recovery from daily wear and tear, are adversely affected. Moreover, participants that otherwise have no self-reported symptoms related to mobile phone use, appear to have more headaches during actual radiofrequency exposure as compared to sham exposure. However, subjects were not able to detect the true exposure status more often than would have been expected by statistical chance alone. Additional self-reported findings, biochemical, performance and electrophysiological data are currently being analyzed. Possible health implications from the findings will also be further explored.
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| 2. |
- Hillert, Lena, et al.
(författare)
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The effects of 884 MHz GSM wireless communication signals on headache and other symptoms : an experimental provocation study.
- 2008
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Ingår i: Bioelectromagnetics. - : Wiley. - 1521-186X .- 0197-8462. ; 29:3, s. 185-96:Nov 28 [Epub ahead of print]
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Tidskriftsartikel (refereegranskat)abstract
- The effects of 884 MHz GSM wireless communication signals on headache and other symptoms: an experimental provocation study.Hillert L, Akerstedt T, Lowden A, Wiholm C, Kuster N, Ebert S, Boutry C, Moffat SD, Berg M, Arnetz BB.Department of Public Health Sciences, Division of Occupational Medicine, Karolinska Institutet, Stockholm, Sweden. lena.hillert@ki.seFindings from prior studies of possible health and physiological effects from mobile phone use have been inconsistent. Exposure periods in provocation studies have been rather short and personal characteristics of the participants poorly defined. We studied the effect of radiofrequency field (RF) on self-reported symptoms and detection of fields after a prolonged exposure time and with a well defined study group including subjects reporting symptoms attributed to mobile phone use. The design was a double blind, cross-over provocation study testing a 3-h long GSM handset exposure versus sham. The study group was 71 subjects age 18-45, including 38 subjects reporting headache or vertigo in relation to mobile phone use (symptom group) and 33 non-symptomatic subjects. Symptoms were scored on a 7-point Likert scale before, after 1(1/2) and 2(3/4) h of exposure. Subjects reported their belief of actual exposure status. The results showed that headache was more commonly reported after RF exposure than sham, mainly due to an increase in the non-symptom group. Neither group could detect RF exposure better than by chance. A belief that the RF exposure had been active was associated with skin symptoms. The higher prevalence of headache in the non-symptom group towards the end of RF exposure justifies further investigation of possible physiological correlates. The current study indicates a need to better characterize study participants in mobile phone exposure studies and differences between symptom and non-symptom groups. (c) 2007 Wiley-Liss, Inc.
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| 3. |
- Lowden, Arne, et al.
(författare)
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Sleep after mobile phone exposure in subjects with mobile phone-related symptoms
- 2011
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Ingår i: Bioelectromagnetics. - : Wiley. - 0197-8462 .- 1521-186X. ; 32:1, s. 4-14
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Tidskriftsartikel (refereegranskat)abstract
- Several studies show increases in activity for certain frequency bands (10-14 Hz) and visually scored parameters during sleep after exposure to radiofrequency electromagnetic fields. A shortened REM latency has also been reported. We investigated the effects of a double-blind radiofrequency exposure (884 MHz, GSM signaling standard including non-DTX and DTX mode, time-averaged 10 g psSAR of 1.4 W/kg) on self-evaluated sleepiness and objective EEG measures during sleep. Forty-eight subjects (mean age 28 years) underwent 3 h of controlled exposure (7:30-10:30 PM; active or sham) prior to sleep, followed by a full-night polysomnographic recording in a sleep laboratory. The results demonstrated that following exposure, time in Stages 3 and 4 sleep (SWS, slow-wave sleep) decreased by 9.5 min (12%) out of a total of 78.6 min, and time in Stage 2 sleep increased by 8.3 min (4%) out of a total of 196.3 min compared to sham. The latency to Stage 3 sleep was also prolonged by 4.8 min after exposure. Power density analysis indicated an enhanced activation in the frequency ranges 0.5-1.5 and 5.75-10.5 Hz during the first 30 min of Stage 2 sleep, with 7.5-11.75 Hz being elevated within the first hour of Stage 2 sleep, and bands 4.75-8.25 Hz elevated during the second hour of Stage 2 sleep. No pronounced power changes were observed in SWS or for the third hour of scored Stage 2 sleep. No differences were found between controls and subjects with prior complaints of mobile phone-related symptoms. The results confirm previous findings that RF exposure increased the EEG alpha range in the sleep EEG, and indicated moderate impairment of SWS. Furthermore, reported differences in sensitivity to mobile phone use were not reflected in sleep parameters.
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| 6. |
- Vogiatzis Oikonomidis, Ioannis, 1989, et al.
(författare)
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Couple Electromagnetic and Neuronal Dynamics Simulation of Gradient Coil Switching Induced Nerve Stimulation
- 2014
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Ingår i: Proceedings: Joint Annual Meeting ISMRM-ESMRMB 2014
SMRT 23rd Annual Meeting 10-16 May, 2014 Milan Italy. ; , s. paper 1388-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Nerve stimulation by rapidly switching gradient coils is a safety concern in MR. An EM and thermal simulation platform has been coupled with a neuronal dynamics modeling code, to investigate such interactions in realistic anatomical models. A locally temperature dependent variant of the SENN model, commonly employed for safety threshold assessment, has been developed. Modeling of sciatic nerve stimulation by gradient coil switching, considering the impact of RF birdcage coil induced heating, showed that the model anisotropy, the field variation along the nerve and local temperature have a relevant impact that can be studied using the coupled EM-neuron simulation platform.
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| 7. |
- Wiholm, Clairy, et al.
(författare)
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Mobile phone exposure and spatial memory.
- 2009
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Ingår i: Bioelectromagnetics. - : Wiley. - 1521-186X .- 0197-8462. ; 30:1, s. 59-65
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Tidskriftsartikel (refereegranskat)abstract
- Radiofrequency (RF) emission during mobile phone use has been suggested to impair cognitive functions, that is, working memory. This study investigated the effects of a 2 1/2 h RF exposure (884 MHz) on spatial memory and learning, using a double-blind repeated measures design. The exposure was designed to mimic that experienced during a real-life mobile phone conversation. The design maximized the exposure to the left hemisphere. The average exposure was peak spatial specific absorption rate (psSAR10g) of 1.4 W/kg. The primary outcome measure was a "virtual" spatial navigation task modeled after the commonly used and validated Morris Water Maze. The distance traveled on each trial and the amount of improvement across trials (i.e., learning) were used as dependent variables. The participants were daily mobile phone users, with and without symptoms attributed to regular mobile phone use. Results revealed a main effect of RF exposure and a significant RF exposure by group effect on distance traveled during the trials. The symptomatic group improved their performance during RF exposure while there was no such effect in the non-symptomatic group. Until this new finding is further investigated, we can only speculate about the cause.
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