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1.
Int J Behav Nutr Phys Act ; 19(1): 2, 2022 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-34991606

RESUMO

BACKGROUND: In 2018, the Australian Government updated the Australian Physical Activity and Sedentary Behaviour Guidelines for Children and Young People. A requirement of this update was the incorporation of a 24-hour approach to movement, recognising the importance of adequate sleep. The purpose of this paper was to describe how the updated Australian 24-Hour Movement Guidelines for Children and Young People (5 to 17 years): an integration of physical activity, sedentary behaviour and sleep were developed and the outcomes from this process. METHODS: The GRADE-ADOLOPMENT approach was used to develop the guidelines. A Leadership Group was formed, who identified existing credible guidelines. The Canadian 24-Hour Movement Guidelines for Children and Youth best met the criteria established by the Leadership Group. These guidelines were evaluated based on the evidence in the GRADE tables, summaries of findings tables and recommendations from the Canadian Guidelines. We conducted updates to each of the Canadian systematic reviews. A Guideline Development Group reviewed, separately and in combination, the evidence for each behaviour. A choice was then made to adopt or adapt the Canadian recommendations for each behaviour or create de novo recommendations. We then conducted an online survey (n=237) along with three focus groups (n=11 in total) and 13 key informant interviews. Stakeholders used these to provide feedback on the draft guidelines. RESULTS: Based on the evidence from the Canadian systematic reviews and the updated systematic reviews in Australia, the Guideline Development Group agreed to adopt the Canadian recommendations and, apart from some minor changes to the wording of good practice statements, maintain the wording of the guidelines, preamble, and title of the Canadian Guidelines. The Australian Guidelines provide evidence-informed recommendations for a healthy day (24-hours), integrating physical activity, sedentary behaviour (including limits to screen time), and sleep for children (5-12 years) and young people (13-17 years). CONCLUSIONS: To our knowledge, this is only the second time the GRADE-ADOLOPMENT approach has been used to develop movement behaviour guidelines. The judgments of the Australian Guideline Development Group did not differ sufficiently to change the directions and strength of the recommendations and as such, the Canadian Guidelines were adopted with only very minor alterations. This allowed the Australian Guidelines to be developed in a shorter time frame and at a lower cost. We recommend the GRADE-ADOLOPMENT approach, especially if a credible set of guidelines that was developed using the GRADE approach is available with all supporting materials. Other countries may consider this approach when developing and/or revising national movement guidelines.


Assuntos
Exercício Físico , Comportamento Sedentário , Adolescente , Austrália , Canadá , Criança , Humanos , Sono
2.
Bioelectromagnetics ; 42(4): 317-328, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33847008

RESUMO

Although there is consistent evidence that exposure to radiofrequency electromagnetic fields (RF-EMF) increases the spontaneous resting alpha spectral power of the electroencephalogram (EEG), the reliability of this evidence is uncertain as some studies have also failed to observe this effect. The present study aimed to determine whether the effect of RF-EMF exposure on EEG alpha power depends on whether EEG is derived from eyes open or closed conditions and assessed earlier (<5-min) versus later (>25-min) in the exposure interval. Thirty-six adults participated in three experimental sessions, each involving one exposure: "Sham," "Low," and "High" RF-EMF corresponding to peak spatial specific absorption rates averaged over 10 g of 0, 1, and 2 W/kg, respectively. Resting EEG was recorded at baseline (no exposure), during, and after exposure. Alpha power increase was found to be greater for the eyes open than eyes closed EEG during both the High (P = 0.04) and Low (P = 0.04) RF-EMF exposures. There was also a trend toward it being larger at the end, versus the start of the "High" 30-min exposure (P < 0.01; eyes open condition). This suggests that the use of eyes closed conditions, and insufficient RF-EMF exposure durations, are likely explanations for the failure of some studies to detect an RF-EMF exposure-related increase in alpha power, as such methodological choices decrease signal-to-noise ratios and increase type II error.


Assuntos
Campos Eletromagnéticos , Ondas de Rádio , Adulto , Eletroencefalografia , Campos Eletromagnéticos/efeitos adversos , Humanos , Ondas de Rádio/efeitos adversos , Reprodutibilidade dos Testes , Descanso
3.
Bioelectromagnetics ; 40(6): 365-374, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31338856

RESUMO

It is well known that applying transcranial alternating current stimulation (tACS) to the scalp can generate artefactual visual perceptions of flashing or shimmering light known as phosphenes. The thresholds for generating these phosphenes have been used by international standards bodies to provide conservative estimates of the field strength required to interfere with human neural functioning and set safety limits accordingly. However, the precise relationship between electric currents and phosphene perception thresholds remains uncertain. The present study used tACS to systematically investigate the effects of the location and the frequency of stimulation on phosphene perception thresholds. These thresholds were obtained from 24 participants using a within-subject design as a function of scalp stimulation sites (FPz-Cz versus Oz-Cz) and stimulation frequency (2-30 Hz in steps of 2 Hz). Phosphene perception thresholds were consistently lower for FPz-Cz stimulation, and regardless of tACS location were lowest for 16 Hz stimulation. Threshold variation between participants was very small, which is meaningful when setting standards based on phosphenes. Bioelectromagnetics. 2019;40:365-374. © 2019 Bioelectromagnetics Society.


Assuntos
Fosfenos/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto , Eletrodos , Feminino , Humanos , Masculino , Estimulação Luminosa , Limiar Sensorial
4.
Artigo em Inglês | MEDLINE | ID: mdl-31035391

RESUMO

There is now strong evidence that radiofrequency electromagnetic field (RF-EMF) exposure influences the human electroencephalogram (EEG). While effects on the alpha band of the resting EEG have been repeatedly shown, the mechanisms underlying that effect have not been established. The current study used well-controlled methods to assess the RF-EMF exposure effect on the EEG and determine whether that effect might be thermally mediated. Thirty-six healthy adults participated in a randomized, double-blind, counterbalanced provocation study. A water-perfusion suit (34 C) was worn throughout the study to negate environmental influences and stabilize skin temperature. Participants attended the laboratory on four occasions, the first being a calibration session and the three subsequent ones being exposure sessions. During each exposure session, EEG and skin temperature (8 sites) were recorded continuously during a baseline phase, and then during a 30 min exposure to a 920 MHz GSM-like signal (Sham, Low RF-EMF (1 W/kg) and High RF-EMF (2 W/kg)). Consistent with previous research, alpha EEG activity increased during the High exposure condition compared to the Sham condition. As a measure of thermoregulatory activation, finger temperature was found to be higher during both exposure conditions compared to the Sham condition, indicating for the first time that the effect on the EEG is accompanied by thermoregulatory changes and suggesting that the effect of RF-EMF on the EEG is consistent with a thermal mechanism.


Assuntos
Eletroencefalografia/métodos , Campos Eletromagnéticos , Ondas de Rádio , Adolescente , Adulto , Pressão Sanguínea/efeitos da radiação , Telefone Celular , Método Duplo-Cego , Feminino , Humanos , Pessoa de Meia-Idade , Descanso , Temperatura Cutânea/efeitos da radiação , Adulto Jovem
5.
Environ Res ; 166: 409-417, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29936289

RESUMO

While there has been consistent evidence that symptoms reported by individuals who suffer from Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF) are not caused by EMF and are more closely associated with a nocebo effect, whether this response is specific to IEI-EMF sufferers and what triggers it, remains unclear. The present experiment tested whether perceived EMF exposure could elicit symptoms in healthy participants, and whether viewing an 'alarmist' video could exacerbate a nocebo response. Participants were randomly assigned to watch either an alarmist (N = 22) or control video (N = 22) before completing a series of sham and active radiofrequency (RF) EMF exposure provocation trials (2 open-label, followed by 12 randomized, double-blind, counterbalanced trials). Pre- and post-video state anxiety and risk perception, as well as belief of exposure and symptom ratings during the open-label and double-blind provocation trials, were assessed. Symptoms were higher in the open-label RF-ON than RF-OFF trial (p < .001). No difference in either symptoms (p = .183) or belief of exposure (p = .144) was observed in the double-blind trials. Participants who viewed the alarmist video had a significant increase in symptoms (p = .041), state anxiety (p < .01) and risk perception (p < .001) relative to the control group. These results reveal the crucial role of awareness and belief in the presentation of symptoms during perceived exposure to EMF, showing that healthy participants exhibit a nocebo response, and that alarmist media reports emphasizing adverse effects of EMF also contribute to a nocebo response.


Assuntos
Campos Eletromagnéticos/efeitos adversos , Sensibilidade Química Múltipla/psicologia , Efeito Nocebo , Método Duplo-Cego , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Ondas de Rádio , Sugestão , Gravação em Vídeo
6.
Clin Neurophysiol ; 129(5): 901-908, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29550650

RESUMO

OBJECTIVE: To use improved methods to address the question of whether acute exposure to radio-frequency (RF) electromagnetic fields (RF-EMF) affects early (80-200 ms) sensory and later (180-600 ms) cognitive processes as indexed by event-related potentials (ERPs). METHODS: Thirty-six healthy subjects completed a visual discrimination task during concurrent exposure to a Global System for Mobile Communications (GSM)-like, 920 MHz signal with peak-spatial specific absorption rate for 10 g of tissue of 0 W/kg of body mass (Sham), 1 W/kg (Low RF) and 2 W/kg (High RF). A fully randomised, counterbalanced, double-blind design was used. RESULTS: P1 amplitude was reduced (p = .02) and anterior N1 latency was increased (p = .04) during Exposure compared to Sham. There were no effects on any other ERP latencies or amplitudes. CONCLUSIONS: RF-EMF exposure may affect early perceptual (P1) and preparatory motor (anterior N1) processes. However, only two ERP indices, out of 56 comparisons, were observed to differ between RF-EMF exposure and Sham, suggesting that these observations may be due to chance. SIGNIFICANCE: These observations are consistent with previous findings that RF-EMF exposure has no reliable impact on cognition (e.g., accuracy and response speed).


Assuntos
Cognição/efeitos da radiação , Campos Eletromagnéticos , Potenciais Evocados Visuais/efeitos da radiação , Percepção Visual/efeitos da radiação , Adolescente , Adulto , Estudos Cross-Over , Discriminação Psicológica/efeitos da radiação , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
7.
Environ Int ; 114: 297-306, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29529581

RESUMO

BACKGROUND: The aim of this study was to quantify RF-EMF exposure applying a tested protocol of RF-EMF exposure measurements using portable devices with a high sampling rate in different microenvironments of Switzerland, Ethiopia, Nepal, South Africa, Australia and the United States of America. METHOD: We used portable measurement devices for assessing RF-EMF exposure in 94 outdoor microenvironments and 18 public transport vehicles. The measurements were taken either by walking with a backpack with the devices at the height of the head and a distance of 20-30 cm from the body, or driving a car with the devices mounted on its roof, which was 170-180 cm above the ground. The measurements were taken for about 30 min while walking and about 15-20 min while driving in each microenvironment, with a sampling rate of once every 4 s (ExpoM-RF) and 5 s (EME Spy 201). RESULTS: Mean total RF-EMF exposure in various outdoor microenvironments varied between 0.23 V/m (non-central residential area in Switzerland) and 1.85 V/m (university area in Australia), and across modes of public transport between 0.32 V/m (bus in rural area in Switzerland) and 0.86 V/m (Auto rickshaw in urban area in Nepal). For most outdoor areas the major exposure contribution was from mobile phone base stations. Otherwise broadcasting was dominant. Uplink from mobile phone handsets was generally very small, except in Swiss trains and some Swiss buses. CONCLUSIONS: This study demonstrates high RF-EMF variability between the 94 selected microenvironments from all over the world. Exposure levels tended to increase with increasing urbanity. In most microenvironments downlink from mobile phone base stations is the most relevant contributor.


Assuntos
Campos Eletromagnéticos , Exposição Ambiental/análise , Monitoramento Ambiental/métodos , Ondas de Rádio , Austrália , Condução de Veículo , Humanos , Nepal , África do Sul , Suíça , Caminhada
8.
Bioelectromagnetics ; 39(2): 132-143, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29125197

RESUMO

The etiology of Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF) is controversial. While the majority of studies have indicated that there is no relationship between EMF exposure and symptoms reported by IEI-EMF sufferers, concerns about methodological issues have been raised. Addressing these concerns, the present experiment was designed as a series of individual case studies to determine whether there is a relationship between radiofrequency-electromagnetic field (RF-EMF) exposure and an IEI-EMF individual's self-reported symptoms. Three participants aged 44-64 were tested during a series of sham and active exposure trials (2 open-label trials; 12 randomized, double-blind, counterbalanced trials), where symptom severity and exposure detection were scored using 100 mm visual analogue scales. The RF-EMF exposure was a 902-928 MHz spread spectrum digitally modulated signal with an average radiated power output of 1 W (0.3 W/m2 incident power density at the participant). In the double-blind trials, no significant difference in symptom severity or exposure detection was found for any of the participants between the two conditions. Belief of exposure strongly predicted symptom severity score for all participants. Despite accounting for several possible limitations, the present experiment failed to show a relationship between RF-EMF exposure and an IEI-EMF individual's symptoms. Bioelectromagnetics. 39:132-143, 2018. © 2017 Wiley Periodicals, Inc.


Assuntos
Campos Eletromagnéticos/efeitos adversos , Sensibilidade Química Múltipla/etiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ondas de Rádio/efeitos adversos , Autorrelato
9.
BMC Public Health ; 17(Suppl 5): 869, 2017 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-29219094

RESUMO

BACKGROUND: In 2017, the Australian Government funded the update of the National Physical Activity Recommendations for Children 0-5 years, with the intention that they be an integration of movement behaviours across the 24-h period. The benefit for Australia was that it could leverage research in Canada in the development of their 24-h guidelines for the early years. Concurrently, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group published a model to produce guidelines based on adoption, adaption and/or de novo development using the GRADE evidence-to-decision framework. Referred to as the GRADE-ADOLOPMENT approach, it allows guideline developers to follow a structured and transparent process in a more efficient manner, potentially avoiding the need to unnecessarily repeat costly tasks such as conducting systematic reviews. The purpose of this paper is to outline the process and outcomes for adapting the Canadian 24-Hour Movement Guidelines for the Early Years to develop the Australian 24-Hour Movement Guidelines for the Early Years guided by the GRADE-ADOLOPMENT framework. METHODS: The development process was guided by the GRADE-ADOLOPMENT approach. A Leadership Group and Consensus Panel were formed and existing credible guidelines identified. The draft Canadian 24-h integrated movement guidelines for the early years best met the criteria established by the Panel. These were evaluated based on the evidence in the GRADE tables, summaries of findings tables and draft recommendations from the Canadian Draft Guidelines. Updates to each of the Canadian systematic reviews were conducted and the Consensus Panel reviewed the evidence for each behaviour separately and made a decision to adopt or adapt the Canadian recommendations for each behaviour or create de novo recommendations. An online survey was then conducted (n = 302) along with five focus groups (n = 30) and five key informant interviews (n = 5) to obtain feedback from stakeholders on the draft guidelines. RESULTS: Based on the evidence from the Canadian systematic reviews and the updated systematic reviews in Australia, the Consensus Panel agreed to adopt the Canadian recommendations and, apart from some minor changes to the wording of good practice statements, keep the wording of the guidelines, preamble and title of the Canadian Guidelines. The Australian Guidelines provide evidence-informed recommendations for a healthy day (24-h), integrating physical activity, sedentary behaviour (including limits to screen time), and sleep for infants (<1 year), toddlers (1-2 years) and preschoolers (3-5 years). CONCLUSIONS: To our knowledge, this is only the second time the GRADE-ADOLOPMENT approach has been used. Following this approach, the judgments of the Australian Consensus Panel did not differ sufficiently to change the directions and strength of the recommendations and as such, the Canadian recommendations were adopted with very minor alterations. This allowed the Guidelines to be developed much faster and at lower cost. As such, we would recommend the GRADE-ADOLOPMENT approach, especially if a credible set of guidelines, with all supporting materials and developed using a transparent process, is available. Other countries may consider using this approach when developing and/or revising national movement guidelines.


Assuntos
Consenso , Comportamento Cooperativo , Exercício Físico , Fidelidade a Diretrizes/organização & administração , Guias como Assunto , Austrália , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Comportamento Sedentário , Sono
10.
Artigo em Inglês | MEDLINE | ID: mdl-27690076

RESUMO

Mobile phone subscriptions continue to increase across the world, with the electromagnetic fields (EMF) emitted by these devices, as well as by related technologies such as Wi-Fi and smart meters, now ubiquitous. This increase in use and consequent exposure to mobile communication (MC)-related EMF has led to concern about possible health effects that could arise from this exposure. Although much research has been conducted since the introduction of these technologies, uncertainty about the impact on health remains. The Australian Centre for Electromagnetic Bioeffects Research (ACEBR) is a National Health and Medical Research Council Centre of Research Excellence that is undertaking research addressing the most important aspects of the MC-EMF health debate, with a strong focus on mechanisms, neurodegenerative diseases, cancer, and exposure dosimetry. This research takes as its starting point the current scientific status quo, but also addresses the adequacy of the evidence for the status quo. Risk communication research complements the above, and aims to ensure that whatever is found, it is communicated effectively and appropriately. This paper provides a summary of this ACEBR research (both completed and ongoing), and discusses the rationale for conducting it in light of the prevailing science.

11.
Int J Radiat Biol ; 92(10): 603-10, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27501119

RESUMO

PURPOSE: To investigate whether exposure to pulse modulated radiofrequency (PM RF) influences human cognitive performance, and whether it does so in a dose-dependent manner. MATERIALS AND METHODS: Thirty-six healthy adults participated in a randomized, double-blind, counterbalanced provocation study. Cognitive performance was assessed using a visual discrimination task and a modified Sternberg working memory task, which were calibrated to individual performance levels in a preliminary testing session. An sXh920 planar exposure system was used to generate a 920 MHz GSM-like signal, providing three conditions (peak-spatial SAR averaged over 10 g) of 0 W/kg (sham), 1 W/kg (low RF) and 2 W/kg (high RF). RESULTS: A significant decrease in reaction time (RT) in the Sternberg working memory task was found during exposure compared to sham. This effect was not dose-dependent. CONCLUSIONS: Cognitive performance was shown to be faster under PM RF conditions, relative to sham, in a working memory task. While the majority of the literature has not found effects of PM RF exposure on cognitive performance, it is possible that the methodological improvements employed in the present study increased sensitivity, and thus the ability to detect potential effects.


Assuntos
Cognição/fisiologia , Memória de Curto Prazo/fisiologia , Adolescente , Adulto , Cognição/efeitos da radiação , Relação Dose-Resposta à Radiação , Método Duplo-Cego , Feminino , Humanos , Masculino , Memória de Curto Prazo/efeitos da radiação , Pessoa de Meia-Idade , Doses de Radiação , Análise e Desempenho de Tarefas , Adulto Jovem
12.
BMC Neurosci ; 14: 117, 2013 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-24103323

RESUMO

BACKGROUND: The human waking EEG spectrum shows high heritability and stability and, despite maturational cortical changes, high test-retest reliability in children and teens. These phenomena have also been shown to be region specific. We examined the stability of the morphology of the wake EEG spectrum in children aged 11 to 13 years recorded over weekly intervals and assessed whether the waking EEG spectrum in children may also be trait-like. Three minutes of eyes open and three minutes of eyes closed waking EEG was recorded in 22 healthy children once a week for three consecutive weeks. Eyes open and closed EEG power density spectra were calculated for two central (C3LM and C4LM) and two occipital (O1LM and O2LM) derivations. A hierarchical cluster analysis was performed to determine whether the morphology of the waking EEG spectrum between 1 and 20 Hz is trait-like. We also examined the stability of the alpha peak using an ANOVA. RESULTS: The morphology of the EEG spectrum recorded from central derivations was highly stable and unique to an individual (correctly classified in 85% of participants), while the EEG recorded from occipital derivations, while stable, was much less unique across individuals (correctly classified in 42% of participants). Furthermore, our analysis revealed an increase in alpha peak height concurrent with a decline in the frequency of the alpha peak across weeks for occipital derivations. No changes in either measure were observed in the central derivations. CONCLUSIONS: Our results indicate that across weekly recordings, power spectra at central derivations exhibit more "trait-like" characteristics than occipital derivations. These results may be relevant for future studies searching for links between phenotypes, such as psychiatric diagnoses, and the underlying genes (i.e., endophenotypes) by suggesting that such studies should make use of more anterior rather than posterior EEG derivations.


Assuntos
Encéfalo/fisiologia , Eletroencefalografia , Vigília , Adolescente , Criança , Análise por Conglomerados , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes
13.
J Sleep Res ; 21(6): 620-9, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22724534

RESUMO

Studies have repeatedly shown that electroencephalographic power during sleep is enhanced in the spindle frequency range following radio frequency electromagnetic field exposures pulse-modulated with fundamental frequency components of 2, 8, 14 or 217 Hz and combinations of these. However, signals used in previous studies also had significant harmonic components above 20 Hz. The current study aimed: (i) to determine if modulation components above 20 Hz, in combination with radio frequency, are necessary to alter the electroencephalogram; and (ii) to test the demodulation hypothesis, if the same effects occur after magnetic field exposure with the same pulse sequence used in the pulse-modulated radio frequency exposure. In a randomized double-blind crossover design, 25 young healthy men were exposed at weekly intervals to three different conditions for 30 min before sleep. Cognitive tasks were also performed during exposure. The conditions were a 2-Hz pulse-modulated radio frequency field, a 2-Hz pulsed magnetic field, and sham. Radio frequency exposure increased electroencephalogram power in the spindle frequency range. Furthermore, delta and theta activity (non-rapid eye movement sleep), and alpha and delta activity (rapid eye movement sleep) were affected following both exposure conditions. No effect on sleep architecture and no clear impact of exposure on cognition was observed. These results demonstrate that both pulse-modulated radio frequency and pulsed magnetic fields affect brain physiology, and the presence of significant frequency components above 20 Hz are not fundamental for these effects to occur. Because responses were not identical for all exposures, the study does not support the hypothesis that effects of radio frequency exposure are based on demodulation of the signal only.


Assuntos
Encéfalo/efeitos da radiação , Eletroencefalografia/efeitos da radiação , Campos Eletromagnéticos/efeitos adversos , Fases do Sono/efeitos da radiação , Adulto , Encéfalo/fisiologia , Estudos Cross-Over , Método Duplo-Cego , Humanos , Masculino , Testes Neuropsicológicos , Polissonografia/instrumentação , Polissonografia/métodos , Fases do Sono/fisiologia , Fatores de Tempo , Adulto Jovem
14.
Bioelectromagnetics ; 33(1): 86-93, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21812009

RESUMO

Mobile phone exposure-related effects on the human electroencephalogram (EEG) have been shown during both waking and sleep states, albeit with slight differences in the frequency affected. This discrepancy, combined with studies that failed to find effects, has led many to conclude that no consistent effects exist. We hypothesised that these differences might partly be due to individual variability in response, and that mobile phone emissions may in fact have large but differential effects on human brain activity. Twenty volunteers from our previous study underwent an adaptation night followed by two experimental nights in which they were randomly exposed to two conditions (Active and Sham), followed by a full-night sleep episode. The EEG spectral power was increased in the sleep spindle frequency range in the first 30 min of non-rapid eye movement (non-REM) sleep following Active exposure. This increase was more prominent in the participants that showed an increase in the original study. These results confirm previous findings of mobile phone-like emissions affecting the EEG during non-REM sleep. Importantly, this low-level effect was also shown to be sensitive to individual variability. Furthermore, this indicates that previous negative results are not strong evidence for a lack of an effect and, given the far-reaching implications of mobile phone research, we may need to rethink the interpretation of results and the manner in which research is conducted in this field.


Assuntos
Telefone Celular , Ondas de Rádio/efeitos adversos , Sono/efeitos da radiação , Adulto , Eletroencefalografia/efeitos da radiação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
15.
J Sleep Res ; 21(1): 50-8, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21489004

RESUMO

Previous studies have observed increases in electroencephalographic power during sleep in the spindle frequency range (approximately 11-15 Hz) after exposure to mobile phone-like radio frequency electromagnetic fields (RF EMF). Results also suggest that pulse modulation of the signal is crucial to induce these effects. Nevertheless, it remains unclear which specific elements of the field are responsible for the observed changes. We investigated whether pulse-modulation frequency components in the range of sleep spindles may be involved in mediating these effects. Thirty young healthy men were exposed, at weekly intervals, to three different conditions for 30 min directly prior to an 8-h sleep period. Exposure consisted of a 900-MHz RF EMF, pulse modulated at 14 Hz or 217 Hz, and a sham control condition. Both active conditions had a peak spatial specific absorption rate of 2 W kg(-1) . During exposure subjects performed three different cognitive tasks (measuring attention, reaction speed and working memory), which were presented in a fixed order. Electroencephalographic power in the spindle frequency range was increased during non-rapid eye movement sleep (2nd episode) following the 14-Hz pulse-modulated condition. A similar but non-significant increase was also observed following the 217-Hz pulse-modulated condition. Importantly, this exposure-induced effect showed considerable individual variability. Regarding cognitive performance, no clear exposure-related effects were seen. Consistent with previous findings, our results provide further evidence that pulse-modulated RF EMF alter brain physiology, although the time-course of the effect remains variable across studies. Additionally, we demonstrated that modulation frequency components within a physiological range may be sufficient to induce these effects.


Assuntos
Cognição/efeitos da radiação , Eletroencefalografia , Campos Eletromagnéticos/efeitos adversos , Ondas de Rádio/efeitos adversos , Fases do Sono/efeitos da radiação , Adulto , Atenção/fisiologia , Atenção/efeitos da radiação , Cognição/fisiologia , Eletroencefalografia/efeitos da radiação , Humanos , Individualidade , Masculino , Memória de Curto Prazo/fisiologia , Memória de Curto Prazo/efeitos da radiação , Polissonografia , Tempo de Reação/fisiologia , Tempo de Reação/efeitos da radiação , Fases do Sono/fisiologia , Fatores de Tempo , Adulto Jovem
16.
Int J Radiat Biol ; 82(2): 69-76, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16546905

RESUMO

PURPOSE: To test whether exposure to the emissions from a digital mobile phone handset prior to sleep alters the secretion of melatonin. MATERIALS AND METHODS: In a double-blind cross-over design, 55 adult volunteers were both actively exposed or sham-exposed (in random order on successive Sunday nights) to mobile phone emissions for 30 min (0.25 W average power). Urine collection occurred immediately prior to retiring to bed and on rising the next morning. Melatonin output was estimated from principal metabolite concentrations (6-sulphatoxymelatonin (aMT6s) via radioimmunoassay), urine volumes and creatinine concentrations. RESULTS: Total melatonin metabolite output (concentration x urine volume) was unchanged between the two exposure conditions (active 14.1+/-1.1 microg; sham 14.6+/-1.3 microg). The pre- and post-bedtime outputs considered separately were also not significantly different, although the pre-bedtime value was less for active versus sham exposure. When melatonin metabolite output was estimated from the ratio of aMT6s to creatinine concentrations, the pre-bedtime value was significantly less (p = 0.037) for active compared to sham. Examination of individual responses is suggestive of a small group of 'responders'. CONCLUSIONS: Total nighttime melatonin output is unchanged by mobile phone handset emissions, but there could be an effect on melatonin onset time.


Assuntos
Telefone Celular/estatística & dados numéricos , Ritmo Circadiano/efeitos da radiação , Exposição Ambiental/estatística & dados numéricos , Melatonina/urina , Micro-Ondas , Adolescente , Adulto , Austrália/epidemiologia , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doses de Radiação
17.
Neuroreport ; 16(17): 1973-6, 2005 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-16272890

RESUMO

Previous research has suggested that exposure to radiofrequency electromagnetic fields increases electroencephalogram spectral power in non-rapid eye movement sleep. Other sleep parameters have also been affected following exposure. We examined whether aspects of sleep architecture show sensitivity to electromagnetic fields emitted by digital mobile phone handsets. Fifty participants were exposed to electromagnetic fields for 30 min prior to sleep. Results showed a decrease in rapid eye movement sleep latency and increased electroencephalogram spectral power in the 11.5-12.25 Hz frequency range during the initial part of sleep following exposure. These results are evidence that mobile phone exposure prior to sleep may promote rapid eye movement sleep and modify the sleep electroencephalogram in the first non-rapid eye movement sleep period.


Assuntos
Telefone Celular , Campos Eletromagnéticos , Sono REM/efeitos da radiação , Adolescente , Adulto , Eletroencefalografia , Exposição Ambiental , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sono/efeitos da radiação
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