Lalic H, Lekic A, Radosevic-Stasic B. · 2001
Researchers investigated genotoxic effects of occupational exposure to ionizing and non-ionizing radiation in 25 hospital workers and 20 radio-relay station workers using chromosome aberration analysis of peripheral blood lymphocytes. Total chromosome aberrations were almost equally higher in both exposed groups compared to unexposed controls. Acentric fragments were the most frequent aberration and were significantly higher in both exposed groups than in controls. Dicentric fragments were also elevated in both exposed groups, while chromatid breaks increased only after ionizing radiation.
Cheever KL et al. · 2001
Researchers exposed pregnant rats to 10 MHz radiofrequency radiation and measured metabolism and distribution of 2-methoxyethanol and its metabolite methoxyacetic acid. Radiofrequency exposure reduced total body clearance of radiolabeled 2-methoxyethanol but did not change methoxyacetic acid levels in serum, embryos, or extraembryonic fluid. Protein adduct formation in embryos did not differ in a way that would explain the reported synergy between radiofrequency radiation and 2-methoxyethanol.
Moustafa YM, Moustafa RM, Belacy A, Abou-El-Ela SH, Ali FM. · 2001
Researchers investigated the effect of acute exposure to radiofrequency fields from commercially available cellular phones on oxidative stress parameters in 12 healthy adult male volunteers. Each volunteer placed the phone in his pocket in standby position with the keypad facing the body. The parameters measured were lipid peroxide and the activities of superoxide dismutase (SOD), total glutathione peroxidase (GSH-Px) and catalase. Plasma lipid peroxide increased significantly after 1, 2, and 4 hours of exposure. SOD and GSH-Px activities in erythrocytes showed significant reduction, while catalase activity did not decrease significantly.
Tattersall JE et al. · 2001
Mausset A, de Seze R, Montpeyroux F, Privat A · 2001
Researchers injected rats with gamma-vinyl-GABA to increase GABA levels and then used immunohistochemistry and image analysis to measure cerebellar GABA content. They exposed rats to 900 MHz pulsed radiofrequency at 4 W/kg SAR and continuous waves at 32 W/kg SAR. Pulsed exposure selectively reduced the stained processes area in the Purkinje cell layer, while continuous exposure decreased optical density in all three cell layers. The authors noted that it is unknown whether these effects are partly due to local tissue heating.
Lushnikov et al. · 2001
Researchers exposed healthy male NMRI mice to 42.0 GHz electromagnetic radiation at an energy flux density of 0.15 mW/cm2 under several different exposure regimes. After repeated exposures for 20 days before immunization, thymic cellularity was reduced by 17.5% and spleen cellularity by 14.5%, both statistically significant. The humoral immune response itself did not change significantly under any of the exposure regimes tested.
Cranfield CG, Wood AW, Anderson V, Menezes KG. · 2001
Researchers tested whether simulated GSM mobile phone signals at 915 MHz and 2 W kg(-1) influence calcium concentration or calcium signalling patterns in a human lymphocyte cell line. No significant changes were found in the regression slope of calcium fluorescence, mean calcium concentration, number of calcium spikes, or mean height of those spikes. A significant alteration in average frequency from Fourier spectra was found in one category only: pulsed wave exposure of activated cells.
Boscol P et al. · 2001
The study investigated the immune systems of 19 women with a mean age of 35 years who had been exposed to electromagnetic fields from radiotelevision broadcasting stations in their residential area for at least 2 years, with a mean exposure duration of 13 years. The exposed group had mean field levels of 4.3 plus or minus 1.4 V/m in the range 500 KHz to 3 GHz, while the control group had nearby residential exposure of less than 1.8 V/m. The exposed women showed statistically significant reductions in several immune cell types and lower in vitro production of IL-2 and interferon-gamma by peripheral blood mononuclear cells. The researchers concluded that high frequency electromagnetic fields reduce cytotoxic activity in the peripheral blood of women without a dose-response effect.
Sykes PJ, McCallum BD, Bangay MJ, Hooker AM, Morley AA. · 2001
Researchers studied the effect of pulsed 900 MHz radiofrequency radiation at 4 W/kg on somatic intrachromosomal recombination in the spleen of pKZ1 mice. Mice were exposed daily for 30 minutes to 900 MHz fields for 1, 5, or 25 days, and spleen sections were screened for DNA inversion events three days after the last exposure. There was no significant difference between control and treated groups in the 1- and 5-day exposure groups, but a significant reduction in inversions was found in the 25-day group.
Maes A, Collier M, Verschaeve L · 2000
Researchers exposed human lymphocytes to 455.7 MHz microwaves from a car phone at a specific absorption rate of approximately 6.5 W/kg. No statistically significant difference was found between microwave-exposed and unexposed control samples for chromosome aberration or sister chromatid exchange frequency. When microwave exposure was followed by MMC treatment, some differences appeared between combined and MMC-only treatments, but results were inconsistent. Combined exposure with X-rays showed no indication of synergistic action between RF fields and X-rays. The authors concluded that the data do not support the hypothesis that RF fields act synergistically with chemical or physical mutagens.
Vijayalaxmi, Leal BZ, Szilagyi M, Prihoda TJ, Meltz ML · 2000
Human peripheral blood samples from three volunteers were exposed to pulsed-wave 2450 MHz radiofrequency radiation for 2 hours. The exposure used a net forward power of 21 W with an average power density of 5 mW/cm2 and a mean specific absorption rate of 2.135 W/kg. DNA damage was measured using the alkaline comet assay immediately and 4 hours after exposure. No significant differences were found in comet tail length, fluorescence intensity, or tail moment between RF-exposed and sham-exposed lymphocytes at either time point. The response of lymphocytes exposed to ionizing radiation was significantly different from RF-radiation- and sham-exposed cells.
Mezhevikina LM, Khramov RN, Lepikhov KA · 2000
Researchers cultured two-cell mouse embryos in vitro and exposed them to electromagnetic irradiation in the millimeter range. After 30 min of exposure, the embryos acquired the ability to develop on their own and could reach the stage of blastocyst in 150 microliters of Whitten cultural medium without serum or growth factors. The authors proposed that millimeter range electromagnetic waves activate metabolic processes and specifically the synthesis of factors controlling early embryonic development in culture.
Chiabrera A, Bianco B, Moggia E, Kaufman JJ, · 2000
The aim of the study was to observe Zeeman-Stark modeling of the RF EMF interaction with ligand binding. The model accounts for ion collision losses, endogenous forces, metabolic non-equilibrium, and thermal noise. The model predicts that ligand binding probability may be affected by low-intensity exogenous EMF when the receptor's potential energy well matches the radiofrequency photon energy. The authors state that the results point toward electromagnetic control of biochemical processes and the need for a new database of safety standards.
Romano-Spica V, Mucci N, Ursini CL, Ianni A, Bhat NK · 2000
Researchers analyzed gene expression in hemopoietic and testicular cell types after exposure to 50 MHz radiofrequency radiation modulated at 16 Hz. They observed overexpression of ets1 mRNA in Jurkat T-lymphoblastoid and Leydig TM3 cell lines only when the 16 Hz modulation was present. A putative candidate gene was also repressed after EMF exposure.
Zotti-Martelli L, Peccatori M, Scarpato R, Migliore L · 2000
Researchers exposed human peripheral blood lymphocytes in vitro to electromagnetic fields at two frequencies, 2.45 and 7.7 GHz, at power densities of 10, 20, and 30 mW/cm2 for 15, 30, and 60 minutes. At a power density of 30 mW/cm2 and after exposures of 30 and 60 minutes, both frequencies led to an induction of micronuclei compared to control cultures. The researchers concluded that microwaves are able to cause cytogenetic damage in human lymphocytes mainly for both high power density and long exposure time.
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.
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.
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.
Krasil'nikov PM · 1999
The study showed that collective excitations occur in an ionic medium on the surface of lipid membranes. These excitations result from fast lateral ion mobility and high-frequency displacement currents in the Stern layer at the charged membrane surface. This mechanism can induce resonant dipole moments on lipid vesicles, potentially underlying vesicle recognition and autooscillation mode of aggregation in colloidal solution.
Paul Raj R, Behari J, Rao AR · 1999
The effect of exposing rats to amplitude-modulated radiofrequency radiation (112 MHz modulated to 16 Hz) during development and growth was examined. Wistar rats 35 days old exposed at 1.0 mW/cm2 (SAR 0.75 W/kg) for 35 days showed enhanced ornithine decarboxylase activity and Ca2+ efflux in brain.
Galat VV et al. · 1999
Researchers investigated the effects of nonthermal millimeter-range electromagnetic radiation on early development of mouse and sea urchin embryos. An MRTA-01E-03 generator with a frequency of 54-78 GHz and radiation intensity of 0.06 mWt/cm2 was used, and embryos were irradiated for 30 minutes at the two-blastomere stage. More mouse embryos reached the blastocyst stage (97.3%) compared with controls (87.5%), and the total cultivation time to reach that stage was shorter (72 h) than in controls (96 h). For sea urchin embryos, the radiation had an effect only when embryos with weakened viability were tested.
Behari J, Kunjilwar KK, and Pyne S · 1998
Researchers studied the effect of low-level amplitude-modulated radiofrequency radiation on Na+–K+-ATPase activity in the brains of developing male Wistar rats aged 23 days. Rats were exposed to carrier wave frequencies of 147 MHz and its sub-harmonic frequencies 73.5 and 36.75 MHz, amplitude modulated at 16 and 76 Hz, for 30–35 days at 3 hours per day. Na+–K+-ATPase activity increased by around 19–20% in rats exposed with amplitude modulation at 16 Hz, and by around 15–16% in rats exposed with amplitude modulation at 76 Hz, compared to controls. The researchers concluded that the effect on Na+–K+-ATPase activity was insensitive to the carrier wave frequencies under investigation.
Phillips et al. · 1998
Researchers exposed Molt-4 T-lymphoblastoid cells in vitro to pulsed radiofrequency signals at cellular telephone frequencies of 813.5625 MHz (iDEN® signal) and 836.55 MHz (TDMA signal) to detect DNA damage. The alkaline comet assay was used to measure DNA single-strand breaks in exposed cell cultures compared to sham-exposed cultures. At an SAR of 24 μW g−1, exposure to the iDEN® signal for 2 h and 21 h significantly increased DNA damage, while at 2.4 μW g−1 the same signal significantly decreased DNA damage. The researchers concluded that the data indicate a need to study the effects of exposure to RF signals on direct DNA damage and on the rate at which DNA damage is repaired.
Vijayalaxmi, Mohan, N, Meltz, ML, Wittler, MA, · 1997
Stagg RB, Thomas WJ, Jones RA, Adey WR · 1997
Researchers exposed transformed and normal rat glial cells to an 836.55 MHz packet-modulated RF field at power densities of 0.09, 0.9, and 9 mW/cm2, with SARs from 0.15 to 59 muW/g. Primary rat glial cells showed no significant differences in DNA synthesis between sham and RF-exposed conditions for either log-phase or serum-starved cultures. C6 glioma cells exposed at 5.9 muW/g SAR showed small but significant increases in thymidine incorporation in 38% of experiments. Growth curves showed no differences between sham and RF-exposed cultures for either cell type, and doubling times of C6 glioma cells did not differ significantly.
