Harvey C, French PW. · 2000
Researchers exposed human immune cells (mast cells) to microwave radiation at 864.3 MHz for 20 minutes daily over a week, using power levels that kept the cells cooler than body temperature. They found that this non-thermal exposure altered the activity of protein kinase C (a key cellular signaling molecule) and changed the expression of three genes, including one linked to cancer development and another associated with cell death.
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.
Unknown authors · 2000
Bornhausen M, Scheingraber H · 2000
Unknown authors · 2000
Researchers used a bacterial conjugation assay with Escherichia coli carrying the transposable element Tn5 as the donor strain. Donor cultures exposed to a 50 Hz, 1.2 mT magnetic field showed stimulated transposition of chromosomal Tn5 to an extrachromosomal episome and subsequent transfer to recipient cells. The transposition increase was mediated by induced synthesis and accumulation of the heat shock proteins DnaK/J. Magnetic field exposure was found to be stimulatory to transposition activity, similar to heat shock and UV irradiation.
Gos P, Eicher B, Kohli J, Heyer WD · 2000
Researchers exposed actively growing and resting yeast cells to 900 MHz fields at specific absorption rates of 0.13 and 1.3 W/kg. Assays measured forward mutation rates at CAN1, petite clone formation, intrachromosomal deletion formation, and intragenic recombination in the ADE2 gene. Fields were also tested in combination with the alkylating agent methyl methansulfonate to assess whether they could enhance genotoxic damage. Fluctuation tests failed to detect any significant effect on any of these measures, in the absence or presence of methyl methansulfonate.
Unknown authors · 2000
Researchers examined the effect of 50 mT, 60 Hz ELFMF on heat-induced HSP-70 expression in HL60RG cells. Exposure to 50 mT ELFMF alone did not increase HSP-70 production. Combined exposure to 50 mT ELFMF and mild heat at 40°C and 42°C suppressed heat-induced HSP-70 expression. This suppression required simultaneous exposure for more than 5 hours. Lower magnetic densities of 5 mT and 0.5 mT did not suppress HSP-70.
Kalns J, Ryan KL, Mason PA, Bruno JG, Gooden R, Kiel JL. · 2000
Unknown authors · 2000
Researchers from Löscher's group in Germany exposed Sprague-Dawley rats to 50-Hz magnetic fields at microtesla flux densities for 13 or 27 weeks using a DMBA breast cancer model. The exposure significantly increased mammary tumor development and growth in those experiments. A similar study by Battelle in the United States did not replicate the effect.
Unknown authors · 2000
German researchers found that 50 Hz magnetic fields at 100 microtesla significantly increased mammary tumor development in rats treated with a cancer-causing chemical. However, when U.S. researchers tried to replicate the study using similar methods, they could not reproduce these findings, highlighting challenges in EMF research reproducibility.
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.
Pakhomov AG et al. · 2000
Researchers compared extremely high power microwave pulses (EHPP) with low power pulses (LPP) at 9.2 GHz on isolated, spontaneously beating frog heart slices. Both exposure types produced the same temperature rise because EHPP train duration and average power were matched to LPP. The effects were proportional to heating, fully reversible, and reproducible with no delayed or irreversible effects observed. A single EHPP train or LPP immediately decreased the inter-beat interval in most cases. Temporary arrest of beats could be observed when microwave heating exceeded physiologically tolerable limits, regardless of exposure type.
Unknown authors · 2000
Unknown authors · 2000
Scientists exposed human mammary and leukemia cells to 60 Hz magnetic fields (the frequency from power lines) for 24 hours to see if this would change cancer-related gene activity. While some genes showed temporary changes, no consistent pattern emerged across repeated experiments, and the researchers found no reliable evidence that power line frequency magnetic fields alter cancer gene expression.
Unknown authors · 2000
Researchers exposed human breast and leukemia cells to 60 Hz magnetic fields (the same frequency as power lines) for 24 hours to see if it changed cancer-related gene activity. While some genes showed temporary changes, no consistent pattern emerged across repeated experiments, suggesting 60 Hz fields don't systematically alter cancer gene expression in these cell types.
Unknown authors · 2000
Researchers attempted to replicate earlier findings by testing whether a 1.5-G 50-Hz magnetic field alters intracellular free calcium in Jurkat lymphocyte T-cells. Cells were randomly assigned to magnetic field, sham field, or no-field exposures for 8 minutes each in a blinded design. The percentage of cells showing calcium transients was 16.5% for magnetic field, 14.6% for sham, and 14.2% for no field, with no statistically significant differences among them. The authors concluded that their methods did not identify responsive cells, if such cells exist, and that the results do not rule out a magnetic field effect on calcium.
Unknown authors · 2000
Daudi cells were exposed to 60 Hz magnetic fields for 20, 40 or 60 min at flux densities of 12.5, 50, 100 or 500 microT. Exposures included sham/sham, exposed/sham or sham/exposed conditions with blinding, and 12-O-Tetradecanoylphorbol-13-acetate (TPA) treatment was used as a positive control. Human MYC expression was measured by northern blot hybridization as an indicator of the responsiveness of Daudi cells to experimental conditions, and beta-2-microglobulin (B2M) expression was measured simultaneously as an internal control. Exposure to 60 Hz magnetic fields did not significantly alter MYC expression in Daudi cells under any exposure condition.
Grant FH, Schlegel RE, · 2000
Researchers evaluated 20 pacemaker-phone combinations involving 6 pacemakers and 9 phones in vitro under worst-case conditions. The phones represented CDMA, TDMA-11 Hz, TDMA-22 Hz, TDMA-50 Hz, and TDMA-217 Hz digital wireless technologies. Small increases in the perpendicular air gap between the phone and the saline surface resulted in a dramatic reduction in interaction, with approximately half of the 208 test runs showing interaction at 1 cm no longer interacting at 2 cm. At a gap of 7.4 cm the percentage of runs with interaction decreased to 1.4%, and the overall interaction rate was less than 0.07% at a perpendicular distance of 8.6 cm.
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.
Gapeev AB, Chemeris NK · 2000
Researchers used a mathematical model to analyze how modulated extremely high frequency electromagnetic radiation affects intracellular calcium concentration in neutrophils. The model showed that the calcium rise depends on both the frequency and phase of the modulating signal relative to chemical stimulation. A rise above 50% of the initial calcium level occurred at about 1 Hz and phase range 0.3-2.5 radians, but only when modulating signal intensity exceeded a threshold and chemical stimulus intensity was high. Added noise changed the phase-frequency characteristics and created multiple response bands with higher Q-factors. The model results matched earlier experimental data showing effects only with extracellular calcium and high calcium ionophore A23187 concentrations.
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.
