Lu ST et al. · 2000
Researchers studied retinal effects of 1.25 GHz high peak power microwaves in Rhesus monkeys. Preexposure and postexposure fundus pictures and angiograms were all within normal limits. Cone photoreceptor response to light flash was enhanced at 8.4 and 20.2 W/kg R-SAR but not at 4.3 W/kg R-SAR. Enhanced glycogen storage in photoreceptors was observed in sham, 8.4, and 20.2 W/kg groups but not in the 4.3 W/kg group. No degenerative changes or ERG depression were observed, and retinal injury was considered very unlikely at 4 W/kg.
Marino C et al. · 2000
Researchers examined possible effects of 900 MHz microwave exposure on the cochlear epithelium of rats. Two experiments used male Sprague-Dawley rats with far-field exposure in a cubic chamber. No statistically significant evidence was obtained at both SAR values. The exposure system and diagnostic apparatus were considered useful for investigating auditory effects, but no evidence was observed with the parameters applied.
Jauchem JR, Ryan KL, Freidagger MR · 2000
Ketamine-anesthetized male Sprague-Dawley rats were exposed to 1 GHz, 10 GHz, or combined 1 and 10 GHz microwaves at a whole-body specific absorption rate of 12 W/kg. Exposures were conducted in E and H orientations under far-field conditions until lethal temperatures were reached. Survival time was shortest at 1 GHz, intermediate for combined frequencies, and longest at 10 GHz, with most differences statistically significant. Temperature values at most sites for combined exposure fell between those of the single-frequency groups. Arterial blood pressure initially increased then decreased until death, heart rate increased throughout, and patterns were similar across all groups.
Unknown authors · 2000
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.
Pashovkina MS, Akoev IG · 2000
Researchers studied the activity of alkaline phosphatase during exposure to pulse-modulated microwave radiation. The carrier frequency was 2375 MHz with modulation pulse rates of 10-390 Hz, on-off time ratio 2, and specific absorption rates of 8 and 0.8 microW/cm2. At a modulation frequency of 70 Hz, alkaline phosphatase activity increased 1.8-2.0 times. Exposure times were 1 and 3 minutes under continuous temperature control.
Koivisto M, Krause CM, Revonsuo A, Laine M, Hamalainen H · 2000
The influence of pulsed radiofrequency (RF) electromagnetic fields of digital GSM mobile phones on working memory in healthy subjects were studied. Memory load was varied from 0 to 3 items in an n-back task, and each subject was tested twice with and without RF exposure at 902 MHz and 217 Hz. The RF field speeded up response times when the memory load was three items, but no effects were observed with lower loads. The results suggest that RF fields have a measurable effect on human cognitive performance and encourage further studies.
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.
Borbely et al. · 1999
Researchers exposed healthy young subjects during an entire night-time sleep episode to a 900 MHz electromagnetic field at a maximum specific absorption rate of 1 W/kg. The exposure schedule consisted of alternating 15-min on-15-min off intervals. Compared with a control night with sham exposure, the amount of waking after sleep onset was reduced from 18 to 12 min, and EEG spectral power in non-rapid eye movement sleep was increased. The researchers concluded that pulsed high-frequency EMF in the range of radiotelephones may promote sleep and modify the sleep EEG.
Velizarov, S, Raskmark, P, Kwee, S, · 1999
Researchers exposed cell cultures to a GSM 960 MHz field in a TEM cell at 39°C and 35°C. Exposed cells showed a significant change in proliferation compared to non-exposed controls at both temperatures. Sham-exposed cells showed no significant change in proliferation at either temperature.
Fesenko, EE, Makar, VR, Novoselova, EG, Sadovnikov, VB, · 1999
Researchers exposed male NMRI mice to whole body microwave irradiation at 8.15-18 GHz and a power density of 1 microW/cm2 and measured tumor necrosis factor (TNF) production in immune cells. Shorter exposures ranging from 5 hours to 3 days significantly enhanced TNF production in peritoneal macrophages and splenic T lymphocytes. Chronic irradiation for 7 days decreased TNF production in peritoneal macrophages. Microwave treatment increased endogenously produced TNF more effectively than lipopolysaccharide, described as one of the most potent stimuli of this cytokine.
de Seze R, Ayoub J, Peray P, Miro L, Touitou Y · 1999
Researchers evaluated maximum serum melatonin concentration, time of maximum, and area under the curve of the hormone profile. Thirty-eight men aged 20 to 32 years were exposed to GSM 900 or DCS 1800 phones for 2 hr/day, 5 days/wk, for 4 wk at maximum power. Blood samples were collected hourly during the night and every 3 hr in the daytime across four sessions at 15-day intervals. The melatonin circadian profile was not disrupted by the exposure.
Linz et al. · 1999
Researchers tested the effects of radio frequency fields at 180, 900, and 1800 MHz on the electrical properties of isolated ventricular myocytes from guinea pigs and rats. The fields were applied using rectangular waveguides or a TEM cell at specific absorption rates up to 880 mW/kg, with 900 and 1800 MHz signals pulsed to the GSM standard. None of the tested electrophysiological parameters, including membrane potential, action potential, L-type calcium current, and potassium currents, were significantly changed by RF exposure. Lowering the temperature from 36°C to 24°C reduced current amplitude by almost 50% and shifted voltage dependence by about 5 mV, but RF exposure at the lower temperature still did not affect L-type calcium current.
Gandhi OP, Lazzi G, Tinniswood A, Yu QS, · 1999
Researchers compared numerical and experimental methods for determining SAR and radiation patterns of handheld wireless telephones at 835 and 1900 MHz. Peak 1-g SARs ranged from 0.13 to 5.41 W/kg, yet agreement between calculated and measured data was generally within plus or minus 20%. The study noted that for a maximum radiated power of 600 mW at 800/900 MHz, peak 1-g SARs can be higher than 1.6 W/kg unless antennas are carefully designed and placed further away from the head.
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.
E.G Novoselova, E.E Fesenko, V.R Makar, V.B Sadovnikov · 1999
Researchers tested the effect of 8.15–18 GHz microwave radiation at a power density of 1 μW/cm2 on TNF production and immune response. A single 5-hour whole-body exposure induced a significant increase in TNF production in peritoneal macrophages and splenic T cells, and the mitogenic response in T lymphocytes also increased. The activation of cellular immunity was observed within 3 days after exposure. A diet containing β-carotene, α-tocopherol, and ubiquinone Q9 increased the activity of macrophages and T cells from irradiated mice.
Schonborn F, Burkhardt M, Kuster N · 1998
In order to investigate the differences in absorption between adults and children due to their differing anatomies, simulations were performed using head phantoms based on MRI scans of an adult and two children aged 3 and 7 years. Ten different tissue types were distinguished and all simulations were performed using a commercial code based on the finite integration technique. The differences in absorption were investigated for the frequencies of 900 MHz and 1,800 MHz using 0.45 lambda dipoles instead of actual mobile phones. The results revealed no significant differences in the absorption of electromagnetic radiation in the near field of sources between adults and children.
Wagner, P, Roschke, J, Mann, K, Hiller, W, Frank, C · 1998
Researchers recorded all-night polysomnographies of 24 healthy male subjects with and without exposure to a circularly polarized 900 MHz pulsed electromagnetic field at 0.2 W/m². Suppression of REM sleep and a sleep-inducing effect under field exposure did not reach statistical significance, so previous results indicating alterations of these sleep parameters could not be replicated. Spectral power analysis also did not reveal any alterations of the EEG rhythms during EMF exposure.
Imaida K et al. · 1998
Researchers exposed male F344 rats to a 929.2 MHz electromagnetic near-field for 90 minutes a day, five days a week, over six weeks. The exposed rats showed no significant difference in GST-P positive foci numbers or areas compared to sham-exposed rats. Maximum local specific absorption rates were 7.2 to 6.6 W/kg in the whole body and 2.0 to 1.7 W/kg in the liver.
Imaida et al. · 1998
Researchers exposed male F344 rats to a 1.439 GHz TDMA electromagnetic near-field for 90 minutes a day, 5 days a week, over 6 weeks. The rats were initiated with diethylnitrosamine and underwent partial hepatectomy at week 3. Peak liver SARs ranged from 1.91 to 0.937 W/kg and whole-body average SARs from 0.680 to 0.453 W/kg at 0.33 W antenna power. Exposure did not significantly alter the numbers or areas of GST-P-positive foci in the liver compared to sham-exposed rats. Serum levels of corticosterone, ACTH, and melatonin were increased in exposed rats.
Walters TJ et al. · 1998
Researchers measured hypothalamic, cortical, tympanic, and rectal temperatures in rats exposed to 2.06 GHz microwave radiation at two power densities. The high-power density was 1700 mW/cm² with specific absorption rates of 1224 W/kg in hypothalamus and 493 W/kg in cortex, while the low-power density was 170 mW/cm² with SARs of 122.4 W/kg and 49.3 W/kg. During high-power exposure, the hypothalamic temperature rose significantly faster than cortical or rectal temperatures, whereas low-power exposure produced more uniform heating. For comparison, warm-water immersion produced uniform heating, while warm ambient exposure and exercise maintained the pre-existing temperature gradient between hypothalamus and cortex.
Novoselova ET, Fesenko EE. · 1998
Researchers studied whether weak electromagnetic waves in the centimeter range could affect tumor necrosis factor production in macrophages from mice. Whole-body microwave irradiation of male NMRI mice, exposure of macrophages in vitro, and irradiation of culture medium with 8.15-18 GHz at a power density of 1 microW/cm2 each caused a significant enhancement of tumor necrosis factor production in peritoneal macrophages.
Braune, S, Wrocklage, C, Raczek, J, Gailus, T, Lucking, CH · 1998
The study enrolled seven healthy men and three women volunteers aged 26 to 36 years in a single-blind placebo-controlled design. Participants were exposed to a GSM 900 MHz signal at 2 Watt with a 217 Hz frame repetition rate for 35 min per session. Blood pressure and heart rate were recorded continuously with a Finapres device, while capillary perfusion was measured with an infrared plethysmograph on the right hand.
Kwee S, Raskmark P · 1998
Researchers exposed transformed human epithelial amnion cells to 960 MHz microwave fields at three power levels and three exposure times using a TEM cell. Cell growth was reduced in exposed cells compared to control and sham-exposed cells. The proliferation response varied with SAR level and exposure duration, showing a linear correlation between power level and growth change. At lower power levels, a longer exposure time was needed to reach the maximum effect, and repeated exposures did not alter the outcome.
Mann et al. · 1998
Researchers exposed healthy humans to a 900 MHz pulsed electromagnetic field (217 Hz, 0.02 mW/cm²) and measured nocturnal hormone profiles of growth hormone, cortisol, luteinizing hormone, and melatonin under polysomnographic control. Cortisol showed a slight, transient elevation that persisted for one hour after exposure onset. No significant changes were found for growth hormone, luteinizing hormone, or melatonin, and sleep EEG showed no significant alterations, though there was a trend toward REM suppression.
