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1.
This study is aimed to investigation of the effect of modulated 450 MHz microwave radiation on the EEG inter-hemispheric asymmetry. Ten cycles of the microwave exposure (1 min off and 1 min on) at fixed modulation frequency were applied on two groups of healthy volunteers. The first group of 13 subjects was exposed to microwave radiation modulated at 14 Hz and the second group of 15 subjects at 40 Hz frequency. The peak specific absorption rate (SAR) average over 1 g was 0.303 W/kg. Differences in SAR between hemispheres were up to 20 dB. Rod antenna was located from the left side of the head. Differences of relative changes in EEG energy between symmetric channels FP1–FP2, T3–T4, P3–P4 and O1–O2 in exposed and sham conditions were analysed. The results showed increase in EEG energy from the left side caused by microwave exposure. Statistical analysis done for the whole group of subjects didn’t reveal significant differences in inter-hemispheres asymmetry between exposed and sham conditions. However, statistical analysis performed for individual subjects detected significant differences in asymmetry caused by exposure for 15–35% of individuals.  相似文献   

2.
Summary This study focuses on discrimination of changes, produced by low-level microwave exposure in intensity and time variability of the human EEG at rest. The power spectral density (PSD) method and nonlinear scaling analysis of the length distribution of low variability periods (LDLVP) were selected for analysis of the EEG signal. During the study, 19 healthy volunteers were exposed to a microwave (450 MHz) of 217 Hz frequency on-off modulation. The field power density at the scalp was 0.16 mW/cm2. The experimental protocol consisted of ten cycles of repetitive microwave exposure. Signals from frontal, temporal, parietal and occipital EEG channels on EEG theta, alpha and beta rhythms were analysed. Exposure to microwave causes average increase of EEG activity. LDLVP analysis discriminated significant effect in time variability for 2 subjects (11%). PSD method detected significant changes in intensity for 4 subjects (21%). The effect of low-level microwave exposure is stronger on EEG beta rhythm in temporal and parietal regions of the human brain.  相似文献   

3.
This study is aimed to clarify whether effect of low-level microwave radiation on human brain differs at different modulation frequencies. Resting EEG recordings were done on different groups of healthy volunteers. The 450 MHz microwave radiation modulated at 40 and 70 Hz (15 subjects) and 217 and 1,000 Hz (19 subjects) frequencies was applied. The results of our previous study at 7, 14 and 21 Hz modulation were included into analysis. Ten cycles of the exposure (1 min off and 1 min on) at each fixed modulation frequencies were applied. The field power density at the scalp was always 0.16 mW/cm2. Our results showed that microwave exposure increased the EEG energy at EEG frequencies lower or close to the modulation frequency. No effect was detected at EEG frequencies higher than the modulation frequency. Statistically significant changes were caused by exposure in the EEG alpha and beta frequency bands; no significant effect was detected in the theta band. Our results suggest that telecommunication devices with complex spectrum of modulation frequencies like mobile phone can affect all human EEG frequency bands.  相似文献   

4.
This study was aimed to investigate the changes in the human electroencephalographic (EEG) signal caused by modulated low-level microwaves. The 450 MHz microwave exposure modulated at 40 Hz and 70 Hz frequencies was applied to a group of 15 volunteers. The field power density at the scalp was 0.16 mW/cm2. Ten cycles of the exposure (1 min on and 1 min off) at both modulation frequencies were applied. Analysis of the EEG signal was performed using three different methods: nonlinear method of scaling analysis for length distribution of low variability periods (LDLVP), relative changes in EEG energy (S-parameter) and beta ratio (H-parameter). The analysis revealed significant changes caused by microwave for the whole group (H-parameter method). The exposure caused increase of the EEG beta power (S-parameter method). Statistically significant changes in EEG were detected for four subjects (26.7%) at 40 Hz modulation frequency (LDLVP method).  相似文献   

5.
Summary This study focuses on an origin of interaction mechanism of microwave radiation with nervous system—quasi-thermal field effect. The microwave field can cause fluctuations and vibration of the charged particles and membranes in tissues. The hypothesis is, that this phenomenon is similar to the effect caused by Brown motion initiated by temperature and results in the same effects without rise in temperature. The electric field of 1 V/cm can introduce disturbance of the thermal equilibrium inside a cell of 10 μm radius, which is equivalent to disturbance produced by temperature rise of 1 K. The hypothesis, that microwave heating should cause an effect independent of the microwave modulation frequency, while field effect depends on modulation frequency, was examined experimentally. The 450 MHz microwave radiation, modulated at 7, 14 and 21 Hz frequencies, power density at the skin 0.16 mW/cm2, was applied. The experimental protocol consisted of two series of five cycles of the repetitive microwave exposure at fixed modulation frequencies. Relative changes in EEG theta, alpha and beta rhythms of the group of 13 healthy volunteers were analysed. Analysis of the experimental data shows that: (1) statistically significant changes in EEG rhythms depend on modulation frequency of the microwave field; (2) microwave stimulation causes an increase of the EEG energy level; (3) the effect is most intense at beta1 rhythm and higher modulation frequencies. These findings confirm the quasi-thermal origin of the effect, different from average heating.  相似文献   

6.
Summary The effects of electromagnetic fields (EMF) emitted by cellular phones on human electroencephalogram (EEG) were studied during an auditory memory task. The experimental method and the experimental setup are introduced as a credible measurement method of EEG. 19 normal subjects (10 women and 9 men) performed the memory task both with and without exposure to a 900 MHz signal, emitted by a dipole antenna placed near the subjects' head. The energy of the EEG signals was calculated at the time domain. A Fourier transform of the EEG signals was done and the EEG energy was also calculated at the frequency domain. As the Parseval's theorem anticipates the energies were identical. The EEG energy was found concentrated at the four basic bands (α (8–13 Hz), β(14–30 Hz), δ (0–4 Hz) and θ(5–7 Hz)). The primary concern of the present study was the gender related influence of EMF on the spectral energy of EEG. The results show evidence of a strong gender—radiation interaction effect on the EEG energy and on the peak amplitudes within each of the four rhythms. Without radiation the spectral power of males is greater than of females, while under exposure the situation is reversed. Under the influence of EMF the spectral power of the males EEG is decreased while that of the females is increased. In conclusion both the baseline EEG and the changes effected to the EEG power spectrum under the influence of EMF seem to be gender dependent.  相似文献   

7.
The present study investigated the influence of electromagnetic fields (EMF), similar to that emitted by mobile phones, on brain activity. Ten women and ten men, matched for age and educational level, performed a short memory task (Wechsler test), with simultaneous Electroencephalogram (EEG) recordings at 15 scalp electrodes, both without (baseline) and with exposure to an 1,800 MHz signal. The EEG energy was found concentrated at the four basic EEG bands [α (8–13 Hz), β (14–30 Hz), δ (0–4 Hz), and θ (5–7 Hz)]. The analysis revealed that in the presence of EMF, the energy of the β band was significantly greater for females than for males at the majority of the electrodes. Since beta oscillation is associated with the shift of attention during the perception, these findings may indicate that the particular EMF (1,800 MHz signal) exerts an influence on this brain activity, which appears to be gender-related.  相似文献   

8.
A growing empirical evidence base identifies environmental noise exposure as an important health problem. While the health effects depend for a great part on personal noise sensitivity and contextual factors, in environmental policy, generic noise standards and procedures based on objective sound levels are used. In this article, the relation between objective and subjective noise exposure variables is further explored by carrying out a residents’ survey in a highly noise polluted area along two highways south of the city centre of Ghent, Belgium. The survey results show only a weak correlation between objective and subjective exposure variables, with both variables demonstrating different associations with the respondents’ background characteristics. While lower-educated and lower-income people are generally higher exposed according to the models, they do not report a higher subjective exposure. People who have been living longer in the area are not necessarily higher exposed according to the models but do report a higher subjective exposure. Most strikingly, owners of a comfortable detached house report a higher subjective exposure than renters of an apartment or small house, while the latter group is significantly higher exposed according to the models. The results support a plea for the joint evaluation of both objective and subjective noise exposure variables in environmental policy and environmental assessments. In addition, the results argue for specific attention for noise exposure of socio-economically vulnerable people and the establishment of a shared knowledge base on noise exposure with both objective and subjective information.  相似文献   

9.
Multiple chemical sensitivity (MCS) is defined as a syndrome with multiple medically unexplained symptoms attributed to low levels of chemically unrelated substances in the environment. The etiology of this syndrome is still unclear. As MCS may be conceptualized as an atypical type of somatoform disorder, the purpose of the study was to examine whether MCS subjects show symptom patterns, personality traits, and perceptual and cognitive styles as typically found in somatoform patients. Nonsensitive controls (n=36) were compared to subjects with moderate (n=35) and high (n=35) MCS intensity with self-report psychological questionnaires and structured interviews for depression and somatoform disorders. The high MCS group scored significantly higher than the other two groups on self-report scales for somatoform symptoms and depression. Moreover, high MCS was strongly associated with the diagnosis of somatoform disorder, and weaker but still significantly with depression. In a stepwise multiple regression analysis, cognitions about environmental threat, trait anxiety, focus on autonomic sensations, and general environmental sensitivity predicted MCS symptoms in the total sample, explaining 53% of the variance. These results support the hypothesis that trait negativity and mechanisms of symptom perception and symptom amplification contribute to the enhanced symptom reports of MCS individuals.  相似文献   

10.
The aim of the study was to assess the long-term effects of electromagnetic radiation (EMR) on cardiovascular system of medical staff in physiotherapy. A number of 52 exposed subjects (4 male and 48 female; aged 47.3 ± 8.7 years), and a control group of 52 subjects, matched by sex and age, with similar job characteristics without EMR exposure were studied. The EMR exposure from devices emitting at 50 Hz, 150 kHz, 27.12 MHz, 2.45 GHz, and optical radiation was assessed. The relative values of EMR for the whole frequency range in each physiotherapy were calculated and the obtained quota was much larger than 1. The workload and psychosocial factors were evaluated, too. The cardiovascular risk factors arterial pressure, lipid profile, body mass index, waist/hip ratio, smoking, alcohol consumption, nutrition, family history of cardiovascular disease were studied. The incidence of hypertension was moderate with the studied physiotherapists (26.9% v.s. 23.8% control group). The total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly higher in the exposed group. The odds ratios indicate higher possibility of becoming dyslipidemic for the exposed to EMR subjects [for TC OR (95% CI) = 1.570 (1.048–2.351) and for LDL-C OR (95% CI) = 1.840 (1.158–2.924)]. In conclusion, our data show that the EMR exposure of the medical staff in physiotherapy could be associated with the adverse effects on cardiovascular system.  相似文献   

11.
The utility and the safety of the extremely low frequencies (ELF) electromagnetic fields in the treatment of numerous diseases have been demonstrated. Moreover, the effects of these fields seem to depend on their respective codes (frequency, intensity, waveform). We want to value the effects and the safety of the therapeutic application of a musically modulated electromagnetic field (TAMMEF) system, which field is piloted by a musical signal and its parameters (frequency, intensity, waveform) are modified in time, randomly varying within the respective ranges, so that all possible codes can occur during a single application. Sixty subjects, affected by shoulder periarthritis were enrolled in the study and randomly divided into three groups of 20 patients each: the first exposed to TAMMEF, the second exposed to ELF, the third exposed to a simulated field. All subjects underwent a cycle of 15 daily sessions of 30 min each and a clinical examination upon enrolment, after 7 days of therapy, at the end of the cycle and at a follow-up 30 days later. All the patients of TAMMEF group and ELF group completed the therapy without the appearance of side effects: they presented a significant improvement of the subjective pain and the functional limitation, which remained stable at the follow-up examination. In those exposed to a simulated field group, there was no improvement of the pain symptoms or articular functionality. This study suggests that the TAMMEF system is efficacious and safe in the control of pain symptoms and in the reduction of functional limitation in patients with shoulder periarthritis. Moreover, the effects of the TAMMEF system cover those produced by the ELF field.  相似文献   

12.
Summary This study is aimed to investigate dependence of nerve pulse conduction velocity on low-level microwave exposure. The changes in fiber membrane permeability or myelin sheath, caused by microwave, should affect nerve pulse conduction velocity. Experimental investigation was carried out for nerve pulse conduction velocity with and without applied microwave field and different orientations of its polarization to the nerve fiber. Microwave radiation of 450 MHz was applied polarized perpendicular or parallel to the nerve fiber. The measured field power density at the skin was 0.87 mW/cm2. Special program was developed for calculation of the nerve pulse conduction velocity in LabView environment. The right nervus medianus motor nerve fibers of 35 young subjects were under the study. The experimental protocol included ten measurements in every cycle of five different exposure conditions. No changes in average values of the conduction velocities discovered in different exposure conditions. Theoretical calculations based on Hodgkin-Huxley model confirm only a weak possible effect. The results showed that low-level microwave radiation did not cause statistically significant change in nerve pulse conduction velocity in human motor nerve fiber.  相似文献   

13.
Numerous studies have demonstrated the utility of extremely low frequencies (ELF) electromagnetic fields in the treatment of pain. Moreover, the effects of these fields seems to depend on their respective codes. In our study we want to value the effects and the safety of the TAMMEF (Therapeutic Application of a Musically Modulated Electromagnetic Field) system, which field is piloted by a musical signal and its parameters are modified in time, randomly varying within the respective ranges, so that all possible codes can occur during a single application. Ninety subjects, affected by chronic low back pain, were enrolled in the study and randomly divided into three groups of 30 patients each: A exposed to TAMMEF, B exposed to ELF, C exposed to a simulated field. All subjects underwent a cycle of 15 daily sessions of 30 minutes each and a clinical examination upon enrolment, after 7 days of therapy, at the end of the cycle and at a follow-up 30 days later. All the patients of groups A and B completed the therapy without the appearance of side effects: they presented a significant improvement of the subjective pain and the functional limitation, which remained stable at the follow-up examination. In group C, there was no improvement of the pain symptoms or articular functionality. This study suggests that the TAMMEF system is efficacious and safe in the treatment of patients with chronic low back pain.  相似文献   

14.
Objectives This paper aims to provide evidence of an inductive electromagnetic bioeffect on the human brain, which is independent from sound waves and produced by mobile phones, in proximal field, through correlating the EEG data obtained from electrodes placed on both normal and cochlear deaf individuals. Methods Two groups of subjects are placed under controlled electromagnetic conditions inside a Faraday chamber, 12 healthy and another 12 suffering from cochlear deafness). Each is sitting on a chair, fitted with additional support, and holding a cellular phone 2 cm away form the right auricular, in order to avoid a thermal effect as much as possible. All of them, relaxed and with their eyes closed, are EEG recorded in a basal state with their mobile phones off. Then, each of them is again recorded under the same conditions but with the mobile on and listening to the same conversation. In order to assess the observed EEG changes, a statistical analysis by means of the FFT (Fast Fourier Transform) was carried out. Results For both, healthy and cochlear deaf, assimilation or integration of the mobile phone signal by some electrodes is to be found. This is due to the increase of amplitudes for alpha and theta waves, whereas the signal is not integrated in other electrodes. By correlating the spectra of frequencies of corresponding EEG records for the same brain areas, we have not observed significative differences for both groups. Conclusions A possible electromagnetic direct inductive, non-thermal, bioeffect on the human brain is observed. This effect is produced by the use of mobile phones and it bears no relation to the sound waves.  相似文献   

15.
The aim of this study was to verify that in a hot environment, the subjective state could affect cognitive performance before any increase in core temperature. Eighteen volunteers performed a planning (OTS) and a reaction time task in hot and control environments. Before starting the cognitive assessment, subjects completed the Positive and Negative Affect Schedule (PANAS) and provided subjective measures of thermal comfort and thermal sensation. Our results showed that while simple tasks were not affected, complex cognitive task performance was significantly reduced in the HOT. Furthermore, although subjects responded faster during the complex task (OTS) they took longer to find the correct solution. Within the 15 min of heat exposure, skin temperature (Tskin) significantly increased by ∼3 °C. However, core temperature remained unchanged and there were cortical excitability alterations that could have influenced cognitive performance. Therefore, the increase in Tskin appears to be a sufficient physiological response to alter the subjective state of individuals and impair effective decision-making that could have important consequences in occupational settings.  相似文献   

16.
The purpose of the present study was to explore whether or not flotation restricted environmental stimulation technique (REST) facilitates the creative problem-solving ability and originality. Sample 1 consisted of 40 subjects, 20 men and 20 women, randomly assigned in equal numbers to either a nonREST group (armchair-sitting) or to a floating REST group. Both groups worked on a `chain puzzle' for 5 min and were then interrupted with 45 min of sitting or floating. The subjects were then given the task of continuing with the creative problem-solving test. Sample 2 consisted of 54 subjects, 27 men and 27 women, randomly assigned in equal numbers to either a nonREST group (armchair-sitting), a dryREST group (lying on a couch in a dark room) or a flotation REST group. The groups then had to fill in a couple of paper-and-pen tests and were given scores on fluency, obvious answers, original answers, elegance and deductive thinking. The results (impaired creative problem-solving ability and higher originality for the floating group) were interpreted as an indication of cognitive function where the primary process still dominates over the secondary process.  相似文献   

17.
Summary Objectives: The aim of this study is to initiate research in the field of biomedical engineering geared towards a reduction of non-thermal effects on the brain due to the use of mobile telephones. This line of research employs devices attached to the back of cellular-telephone cases. Methods: Under electromagnetic-environment controlled conditions EEG records have been obtained in 16 healthy subjects, with their eyes open at the base-line. These records were compared with the use of the mobile telephone with and without one of these devices for five minutes each, and having them statistically tested with Wilcoxon matched-pairs. Results: Differences between experimental EEG, with and without the use of the device, have been observed. These subtle changes basically affect Delta and Theta wave bands. Their distribution, (changes in the affected areas of the brain), also varies, above all in the frontal areas. Conclusions: The use of this device could reduce non-thermal effects of mobile telephones on the human EEG.  相似文献   

18.
Osteoarthritis (OA) is the most common joint disorder, associated with loss of articular cartilage, osteophyte formation, subchodral bone change, synovitis and characterized by chronic and often disabling pain and stiffness of one or more joints. The pathogenesis of the disease is complex and still debated, even if recent studies have shown that reactive oxygen species may participate in the initiation and progression of OA. Moreover, it is known that pulsed electromagnetic fields are useful in the OA treatment, owing to their analgesic and anti-inflammatory properties. This work evaluated lipid peroxidation, glutathione, and ascorbic acid levels in patients with OA of spine, before and after the application of a new electromagnetic system, the TAMMEF (Therapeutic Application of a Musically Modulated Electromagnetic Field) system. In TAMMEF system, the extremely low frequencies electromagnetic field is piloted by a musical signal and its parameters (frequency, intensity, waveform) are modified in time, randomly varying within the respective ranges: so all possible codes can occur during a single application. Twenty patients affected by OA of spine and 20 healthy subjects were enrolled in this study. Plasma levels of ascorbic acid (AA), glutathione (GSH) and malondialdehyde (MDA) (as index of lipid peroxidation) were determined in patients and controls, before the beginning of treatment (first day of therapy) and at the end of cycle. All patients underwent a cycle of 10 daily sessions of 30 min each. Our study showed a significant increase of MDA level and a significant decrease of both AA and GSH levels in patients with OA compared to control group. These findings support the role of oxidative stress in the pathogenesis of OA. After TAMMEF treatment in the OA group, analysis revealed a significant decrease in plasma MDA and AA levels (P < 0.05 and P < 0.01, respectively), no significant difference in GSH levels. Reduction in MDA level could be due to the decreased generation of reactive oxygen species and/or to the increased detoxification activity mediated by GSH. No significant difference in GSH levels, evidenced in OA patients after TAMMEF treatment, could be due to effect sparing of AA on GSH. Furthermore, a beneficial symptomatic effect was observed in all patients.  相似文献   

19.
EEG's and skin temperature measurements were made on six men and six women while sleeping in environments whose temperatures were 10·0°C, 21·1°C, and 32·2°C. Analysis of the EEG recordings showed that the proportion of time in each sleep stage was not affected by the temperature of the sleep environment. The weighted mean skin temperatures of the subjects were similar for the 10·0°C and 21·1°C condition, with a mean of 34·5°C for the sleep period. The mean weighted skin temperature for the 32·2°C condition was 35·6°C. A questionnaire administered when the subjects had awakened showed that women did not sleep as well at 10·0°C as at the other temperatures, when sleeping in conventional bedding and clothing.  相似文献   

20.
ICNIRP于2020年3月出版了2020年版《限制电磁场暴露的导则(100 kHz~300 GHz)》,为了准确掌握2020版导则在基本限值和导出限值方面与旧版导则的差异,通过对比新旧导则对应条款得到具体变化情况。2020版导则修订了全身暴露基本限值与导出限值、局部暴露基本限值、神经刺激基本限值、肢体感应电流导出限值,增加了局部暴露导出限值、短暂局部暴露基本限值与导出限值,删除了微波听觉效应基本限值、接触电流导出限值。2020版导则更新了限制射频电磁场暴露的科学基础,使限值更加匹配近年来的科学研究成果,提升了导则的科学性、严谨性和准确性。  相似文献   

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