Chia SE, Chia HP, Tan JS · 2000
Researchers conducted a cross-sectional community study in Singapore with 808 men and women aged 12 to 70 years selected by one-stage cluster random sampling. The prevalence of handheld cellular telephone users was 44.8%, and headache was the most prevalent symptom among users compared to nonusers with an adjusted prevalence rate ratio of 1.31 (95% CI 1.00-1.70). Headache prevalence increased significantly with increasing daily usage duration, while using hands-free equipment reduced headache prevalence by more than 20% compared to never using it. Handheld telephone use was not associated with a significant increase in other central nervous system symptoms.
Cao Z, Liu J, Li S, Zhao X. · 2000
Researchers selected 81 staff with cellular telephone handsets and 63 staff without handsets from corporations as subjects. They investigated subjects using questionnaires on health, lifestyle, handset use, and the neurobehavioral core test battery. Data were analyzed with chi-square, stepwise regression, and covariance statistics. Handset users had longer average reaction times than non-users (P < 0.01). Longer handset use was negatively associated with corrected reaction number (P < 0.01) and positively associated with fast and slowest reaction times (P < 0.01, P < 0.05), and the authors suggested that handset use could cause adverse neurobehavioral effects.
Apollonio F, D'Inzeo G, Tarricone L. · 2000
The study presents an evaluation of microwave field effects on the acetylcholine receptor channel based on energy issues. Observation of biochemical parameters demonstrated that microwave fields cause conformational changes in the receptor site. An energetic mapping of acetylcholine conformational changes was achieved, clearing ground for future molecular simulations. The channel was considered a stochastic automaton flipping randomly between states, and the incident field modifies transitions among the states.
Wang, BM, Lai, H · 2000
Rats were trained in six sessions to locate a submerged platform in a circular water maze. They were exposed to pulsed 2450-MHz microwaves for 1 hour before each training session. Microwave-exposed rats were slower than sham-exposed and cage control rats in learning to locate the platform. During the probe trial, microwave-exposed animals spent significantly less time in the quadrant that had contained the platform. There was no significant difference in swim speed among the three groups.
Lebedeva NN et al. · 2000
EEG was recorded from 16 standard leads during eyes-open and eyes-closed conditions and analyzed with custom non-linear dynamics software that computed a multichannel global correlation dimension. A significant increase in global correlation dimension occurred during and after exposure, more pronounced with eyes closed. The authors interpreted this increase as a manifestation of cortex activation under phone EMF exposure.
Ivanova VIu, Martynova OV, Aleinik SV, Limarenko AV. · 2000
Researchers studied the effect of modulated electromagnetic fields on brainwave activity in awake cats by recording electroencephalograms from the skin surface in the vertex area using carbon electrodes. In normal cats, brainwave components above 20 Hz predominated, but during electromagnetic field exposure at 980 MHz and a power density of 30–50 microW/cm2, components in the 12–18 Hz range began to prevail instead. A similar redistribution of brainwave power was also seen with acoustic stimulation, and the researchers suggested a common neurophysiological mechanism underlying both effects.
Huber R et al. · 2000
Researchers exposed healthy young male subjects for 30 minutes to EMF at 900 MHz and a spatial peak specific absorption rate of 1 W/kg during the waking period before sleep. Compared with a sham exposure control condition, EEG spectral power during non-rapid eye movement sleep was increased, with the maximum rise in the 9.75-11.25 Hz and 12.5-13.25 Hz bands during the initial part of sleep. The researchers concluded that the changes of brain function induced by pulsed high-frequency EMF outlast the exposure period.
Cobb BL et al. · 2000
Researchers exposed pregnant rats to UWB electromagnetic fields during gestation days 3-18, with some pups also exposed for 10 days after birth, then evaluated offspring for behavioral, functional, and morphological effects. UWB-exposed pups emitted significantly more stress vocalizations than sham-exposed pups, and the medial-to-lateral length of the hippocampus was significantly longer in UWB-exposed pups than in sham-exposed animals. Researchers noted there does not appear to be a unifying physiological or behavioral relationship among the significant differences observed.
Adey WR et al. · 2000
Researchers exposed Fischer 344 rats to a frequency-modulated signal at 836.55 MHz in a two-year bioassay, testing for effects on spontaneous and chemically induced central nervous system tumors. The study used six groups of offspring totaling 540 rats, with some groups receiving the chemical ENU and others sham or field exposure. No FM field-mediated changes were observed in number, incidence, or histological type of either spontaneous or ENU-induced brain tumors, nor were gender differences detected in tumor numbers.
Noda Y, Mori A, Liburdy RP, Packer L · 2000
Researchers investigated the effect of pulsed magnetic fields on nitric oxide synthase (NOS) activity in the rat brain. A significant increase in NOS activity was observed in the cerebellum at 111.2±2.0% (P<0.05) for a 1 Gauss (0.1 mT) pulsed DC field, across five separate experiments. Neither AC nor static DC field treatment showed any significant change in NOS activity. In the hippocampus, cortex, medulla oblongata, hypothalamus, striatum, and midbrain, only a slight change or no effect was observed.
Unknown authors · 1999
Unknown authors · 1999
Researchers investigated symptoms and risk indicators of reported hypersensitivity to electricity using a survey at a telecommunications corporation and comparisons with referred patients. No association was found between psychosocial work characteristics or personal traits and hypersensitivity to electricity. Results indicate that skin symptoms, not neurovegetative symptoms, characterize the syndrome at least during the first years of illness.
Unknown authors · 1999
Researchers conducted a double-blind laboratory study of 24 healthy young men to examine effects of intermittent versus continuous exposure to a 60 Hz, 28.3 microT magnetic field on EEG measures of night sleep. Intermittent exposure was associated with less total sleep time, reduced sleep efficiency, increased Stage II sleep, and decreased REM sleep, while continuous and sham exposure showed no such effects. Subjects exposed intermittently reported sleeping less well and feeling less rested in the morning compared to the other groups. All observed effects were significant at P < or = .04 or less.
Miller SA, Bronson ME, Murphy MR · 1999
Higashikubo R et al. · 1999
Researchers exposed Fischer 344 rats implanted with 9L gliosarcoma cells to 835.62 MHz FMCW or 847.74 MHz CDMA fields with a nominal brain specific absorption rate of 0.75 +/- 0.25 W/kg. The animals were exposed for 4 hours a day, 5 days a week, starting 4 weeks before tumor implantation and continuing up to 150 days after. Sham-exposed rats injected with 2 to 10 cells had a median survival of 70 days with 27% surviving to 150 days; those with 11 to 36 cells had a median survival of 52 days and 14% final survival; those with 37 to 100 cells had a median survival of 45 days and 0% survival. Statistical comparison showed no significant differences in survival curves between RF-exposed and sham-exposed animals in any of the three cell-dose groups.
Wu Y, Jia Y, Guo Y, Zheng Z · 1999
Wistar rats were divided into four groups with three exposure groups and one control group, and learning was measured with a Y-maze followed by neurotransmitter detection in brain areas. Learning ability decreased in exposure groups over three days of EMP exposure compared with controls. After one day, hippocampal 5-HT and DOPAC increased and hypothalamic dopamine increased while hypothalamic Adr decreased; after the second day, hippocampal Adr and 5-HT reduced; after the third day, hippocampal Adr remained lower than control.
Sidorenko AV · 1999
Researchers used the nonlinear dynamics method together with the spectral correlation method to process animal electrocorticograms. They found that the nonlinear dynamics method may be used to analyze electrocorticograms in different functional states, confirmed by increased correlation dimensionality in animals exposed to microwaves or given strychnine. Correlation dimensionality serves as a numerical criterion for comparing dynamic states of the system.
Preece et al. · 1999
Thirty-six participants completed a randomized three-way crossover study with two training sessions and three test sessions. The only cognitive measure that changed was choice reaction time, which became faster, while word, number, picture recall and spatial memory were unchanged.
Morrissey JJ et al. · 1999
Researchers investigated the effects of a one-hour exposure of mice to a 1.6-GHz radiofrequency signal, either continuous wave or pulse-modulated at 11 Hz (IRIDIUM), on c-fos gene expression in the brain. C-fos expression was not significantly elevated until exposure levels exceeded six times the peak dose and 30 times the whole-body average dose relative to human cellular telephone exposure limits. The pattern of c-fos elevation in limbic cortex and subcortex areas was consistent with a stress response due to thermal perception and restraint, not a direct interaction of IRIDIUM energy with brain tissue.
Lamble D, Kauranen T, Laakso M, Summala H · 1999
Nineteen participants aged 20 to 29 years drove at 80 km/h, 50 m behind a lead car on a 30 km motorway section. The lead car decelerated at 0.47 m/s² while participants either looked ahead, dialed numbers, or performed a memory and addition task. Detection ability was impaired by about 0.5 s in brake reaction time and almost 1 s in time-to-collision during the non-visual task. This impairment was similar to when drivers divided visual attention by dialing numbers.
Khudnitskii, SS, Moshkarev, EA, Fomenko, TV, · 1999
The authors studied the influence of ultrahigh frequency radiation from cellular phones on the functional state of the central nervous and cardiovascular systems and on local temperature changes in users. The head area near the phone antenna appeared to be under the most intensive heating, and ultrahigh frequency radiation induced significant changes in local temperature and physiologic parameters of the central nervous and cardiovascular systems.
Kellenyi, L, Thuroczy, G, Faludy, B, Lenard, L · 1999
The study investigated effects of mobile GSM radiotelephone exposure on the auditory brainstem response. A 15-minute exposure to GSM phone radiation caused an increase in auditory brainstem response in the exposed side of human subjects. Subjects also showed a hearing deficiency in the high frequency range of 20 dB from 2 KHz to 10 KHz.
Johnson EH, Chima SC, Muirhead DE · 1999
Researchers examined an adult squirrel monkey with a history of long-term exposure to microwave radiation that had a malignant tumor in the right cerebral cortex. Microscopy showed sheets of moderate-sized cells with clear cytoplasm and central nuclei, resembling an oligodendroglioma, with malignant features including nuclear pleomorphism, mitotic figures, and necrosis. Immunohistochemical analysis supported a neuronal origin with positivity for neurofilament proteins and neuron-specific enolase, while vimentin and glial fibrillary acidic protein were negative except in reactive astrocytes. The tumor showed strong positivity for Ki-67 antigen and p53 oncoprotein, indicating aggressive malignant nature, and was diagnosed as a cerebral primitive neuroectodermal tumor.
Hladky, A, Musil, J, Roth, Z, Urban, P, Blazkova, V · 1999
Twenty volunteers participated in two experiments using a Motorola GSM 8700 mobile phone. Electromagnetic fields during a 5-minute speaking task did not affect visual evoked potentials. A 6-minute exposure also showed no effect on memory and attention tests, but the phone call itself impaired switching attention performance, significantly worsening response and decision speed.
Hardell et al. · 1999
Researchers conducted a case-control study with 209 brain tumour cases and 425 controls in Sweden. Overall cellular telephone use yielded an odds ratio of 0.98 with a 95% confidence interval. Separate analyses for the digital GSM system and the analogue NMT system gave odds ratios of 0.97 and 0.94 respectively. A non-significantly increased risk was found for tumours in the temporal or occipital lobe on the same side as phone use. The increased risk was only seen for use of the NMT system.
