Unknown authors · 2004
Case reports of peripheral neurological effects of radiofrequency radiation describe mainly disturbances of noxious sensation called dysaesthesia. Cases have arisen after exposure to much of the frequency range from low MHz to GHz. After very high intensity exposures nerves may be grossly injured; however, after lower intensity exposures which may result in dysaesthesia, ordinary nerve conduction studies demonstrate no abnormality although current perception threshold studies may. Only a small proportion of similarly exposed persons develop symptoms. Some observations are not consistent with the hypothesis that all health effects of radiofrequency radiation arise from thermal mechanisms.
Yao K, Wang KJ, Sun ZH, Tan J, Xu W, Zhu LJ, Lu de Q. · 2004
Researchers exposed cultured rabbit lens epithelial cells to continuous 2,450 MHz microwave radiation at power densities of 0.10, 0.25, 0.50, 1.00, and 2.00 mW/cm2 for 8 hours. P27Kip1 protein expression increased markedly but its mRNA levels did not change, and P21WAF1 protein and mRNA levels showed no detectable differences between exposed and control groups.
Zmyslony M, Rajkowska E, Mamrot P, Politanski P, Jajte J · 2004
Researchers tested whether weak 50 Hz magnetic fields affect the number of free oxygen radicals in rat lymphocytes in vitro. Rat lymphocytes were exposed for one hour to 50 Hz magnetic fields at 20, 40, or 200 μT, with the field axis either along or crosswise to Earth's static magnetic field. Only at 40 μT, when the field was directed along Earth's static magnetic field, was there a decrease in fluorescence compared to non-exposed samples.
Kim MJ, Rhee SJ. · 2004
Researchers exposed rats to 2.45 GHz microwave radiation for 15 minutes and then fed them diets containing 0%, 0.25%, or 0.5% catechin. Microwave exposure increased cytochrome P450 levels by 85% and NADPH-cytochrome P450 reductase activity by 29% compared with normal rats. It also raised superoxide radical concentrations by 35% and decreased superoxide dismutase activity by 34% and glutathione peroxidase activity by 28%. Catechin supplementation at 0.25% and 0.5% lowered superoxide radicals by 11% and 12%, increased superoxide dismutase activity by 19% and 25%, and kept glutathione peroxidase near normal.
Hinrichs H, Heinze HJ. · 2004
Researchers investigated potential effects of GSM 1800 electromagnetic fields on verbal memory encoding by recording event-related magnetic fields from the brain during subsequent memory retrieval. Twelve normal subjects each completed two experimental sessions, one with EMF exposure during the study phase and one without. Exposure to EMF changed an early (350-400 ms) task-specific component of the event-related magnetic field, indicating interference with item encoding. Behavioral measures were not significantly affected.
Kojima M et al. · 2004
Researchers exposed one eye each of 43 male pigmented rabbits to microwaves at 300 mW/cm2, either under systemic anesthesia or without anesthesia. Exposed eyes showed miosis, conjunctival congestion, corneal edema, and increased light scattering in the lens, and all of these anterior ocular changes disappeared within a week. Rabbits under systemic anesthesia showed much stronger symptoms, and their ocular temperatures were 2-9 degrees C higher than those without anesthesia.
Busljeta I, Trosic I, Milkovic-Kraus S. · 2004
Researchers exposed rats to 2.45 GHz radiation (WiFi frequency) for 2 hours daily and found it disrupted blood cell production in bone marrow while increasing genetic damage markers. These effects occurred at non-heating power levels, suggesting biological impacts below thermal thresholds.
Trosic I, Busljeta I, Pavicic I. · 2004
Researchers investigated the effect of 2.45 GHz microwave irradiation on blood-forming cells in rats. Rats were exposed to a field power density of 5-10 mW/cm2 and a whole-body average SAR of 1-2 W/kg for 2 hours a day, 7 days a week, for 2, 8, 15, or 30 days. A significant decrease in lymphoblast count was observed at 15 and 30 days, while other examined parameters did not differ significantly from sham-exposed controls.
Ding GR et al. · 2004
Researchers tested whether exposure to an extremely low frequency magnetic field affects hydrogen peroxide-induced cell death in human leukaemia HL-60 cells. Simultaneous treatment with the magnetic field and hydrogen peroxide for 24 hours significantly increased the number of apoptotic and necrotic cells compared with cells treated with hydrogen peroxide alone. The researchers found that active caspase-7 protein levels were higher in cells exposed to both the magnetic field and hydrogen peroxide than in those treated with hydrogen peroxide alone, and that poly(ADP-ribose) polymerase cleavage occurred earlier under combined exposure.
Munoz S, Sebastian JL, Sancho M, Miranda JM · 2004
Researchers calculated the transmembrane voltage induced on erythrocyte, codocyte, ovalocyte, and spherocyte cell models exposed to a linearly polarized electromagnetic plane wave at 1800 MHz. The induced voltage on the original erythrocyte shape was higher than on the altered cell geometries. Erythrocyte shape and membrane electric permittivity were found to play a fundamental role in the induced transmembrane voltage values. A finite element numerical technique with adaptive meshing was used for the calculations.
Ramundo-Orlando A, Liberti M, Mossa G, D'Inzeo G. · 2004
Enzyme activity decreased only at 5.6 W/kg, with no response at lower SAR values. When using deglycated ascorbate oxidase without oligosaccharide chains, microwave irradiation caused no enzyme activity changes, indicating the chains are necessary for the effect. Catalytic properties of both enzyme forms were unaffected by microwave exposure in solution or in liposomes, ruling out enzyme conformational changes as a mechanism. The authors concluded that oligosaccharide chains of ascorbate oxidase are critical for microwave effects on lipid membranes.
Zmyślony M et al. · 2004
Unknown authors · 2004
They measured cytoplasmic free calcium using the ratiometric fura-2 technique and mitochondrial membrane potential using the JC-1 probe. Exposure caused a highly significant increase in DNA strand breaks measured by the comet assay. No changes were observed in JC-1 fluorescence or cytoplasmic free calcium compared to sham-exposed cells.
Novoselova EG et al. · 2004
Researchers studied effects of weak microwaves (8.15–18 GHz, 1 µW/cm2, 1.5 h daily) and antioxidant diet on TNF production in healthy and tumor-bearing mice. Microwave radiation and antioxidant diet stimulated TNF production in cells from healthy mice. In tumor-bearing mice, microwave exposure increased TNF production compared to unirradiated mice, while antioxidant diet did not affect TNF secretion. Prolonged microwave treatment decreased tumor growth rate and increased longevity in tumor-bearing mice, but antioxidant diet did not.
Vorobyov V, Pesic V, Janac B, Prolic Z. · 2004
Researchers exposed rats repeatedly for three days to low-intensity 915 MHz microwaves modulated at 4 Hz and recorded EEG from the somatosensory cortex. Microwave exposure alone significantly enhanced fast EEG rhythms (18-30 Hz), an effect not seen in sham-exposed or radiation-naïve rats. In microwave-exposed rats, scopolamine did not cause the EEG slowing observed in non-exposed rats, and its effect resembled that of physostigmine in naive animals.
Busljeta I, Trosic I, Milkovic-Kraus S. · 2004
The study observed erythropoietic changes in rats subchronically exposed to radiofrequency microwave radiation at a nonthermal level. Adult male Wistar rats were exposed to 2.45 GHz continuous RF/MW fields for 2 hours daily, 7 days a week, at 5 – 10 mW/cm2. In exposed animals, erythrocyte count, haemoglobin and haematocrit were increased in peripheral blood on irradiation days 8 and 15. Anuclear cells and erythropoietic precursor cells were significantly decreased in the bone marrow on day 15, while micronucleated cells' frequency was increased.
Trosic I, Busljeta I, Modlic B. · 2004
Researchers used an erythrocyte micronucleus assay to investigate genetic damage in bone marrow red cells of rats exposed to radiofrequency/microwave radiation. Wistar rats were exposed to a 2.45 GHz continuous field for 2 hours daily, 7 days a week, at a power density of 5–10 mW/cm2, with a whole body average specific absorption rate calculated to be 1.25 ± 0.36 W/kg. Significant differences in polychromatic erythrocytes were found on experimental days 8 and 15, and the frequency of micronucleated polychromatic erythrocytes was also significantly increased on day 15. Comparisons after 2, 8, and 30 irradiation treatments did not reveal statistically significant differences between sham-exposed and treated subgroups.
Sarimov R et al. · 2004
Researchers exposed lymphocytes from seven healthy persons to GSM microwaves at different frequencies in the range of 895-915 MHz and measured changes in chromatin conformation. A 30-min exposure at 900 and 905 MHz produced statistically significant condensation of chromatin in lymphocytes from 1 of 3 tested donors. Stronger effects were found following 1-h exposure, with chromatin condensation in 3 donors and decondensation in 1 donor. The observed chromatin changes were similar to effects of heat shock within the temperature window of 40/spl deg/C-44/spl deg/C.
Koyama S et al. · 2004
Researchers tested whether an extremely low-frequency magnetic field (ELFMF) could affect mutations caused by hydrogen peroxide in pTN89 plasmids. Mutations were detected in the supF gene carried by the plasmids in Escherichia coli. The mutation frequency was 2.28×10−4 for hydrogen peroxide treatment alone, and 5.81×10−4 when the ELFMF was applied at the same time. No mutations were observed with ELFMF exposure alone, and the researchers indicated that the ELFMF may potentiate hydrogen peroxide-induced mutation.
Lee BC et al. · 2004
Researchers investigated whether a 60 Hz magnetic field could affect the antioxidant defense system in mouse brain by measuring chemiluminescence and superoxide dismutase (SOD) activity in brain homogenates. A chemiluminescence measure linked to oxidative stress was significantly increased in mice exposed to 60 Hz, 12 G for 3 hours compared to the sham-exposed control group. Brain SOD activity was also significantly increased in the exposed group. The researchers suggest these results indicate the field could deteriorate the antioxidant defensive system through reactive oxygen species other than superoxide radicals.
Rollwitz J, Lupke M, Simkó M · 2004
Researchers studied the effects of 50 Hz magnetic fields on free radical production in mouse bone marrow-derived macrophages and monocytes. Exposure to the magnetic fields at a flux density of 1 mT produced a significant increase in free radical production in both cell types. The radicals produced were mainly superoxide anion radicals, found in macrophages at 33% and in their precursor cells at 24%.
Anderson LE et al. · 2004
Researchers set out to determine whether long-term exposure to a 1.6 GHz radiofrequency field would affect cancer incidence in Fischer 344 rats. Offspring were exposed to near-field radiofrequency signals at brain SAR levels of 1.6 W/kg or 0.16 W/kg for 2 hours per day, 5 days per week, from about 36 days old until they were 2 years old. No statistically significant differences were found among treatment groups for neoplastic lesions or other clinical signs.
Cassel JC, Cosquer B, Galani R, Kuster N. · 2004
Rats were tested in a 12-arm radial-maze after daily exposure to 2.45 GHz microwaves for 45 minutes at a SAR of 0.6 W/kg. The performance of exposed rats was comparable to that found in sham-exposed or in naive rats.
Sarimov et al. · 2004
Researchers exposed human white blood cells (lymphocytes) to cell phone radiation at levels similar to what phones emit during calls. They found that 30-60 minutes of exposure caused changes in the DNA packaging inside cells that were similar to heat stress damage. These cellular changes occurred in most test subjects and suggest that phone radiation may trigger stress responses in our immune cells even at low power levels.
Sarimov et al. · 2004
Researchers exposed human immune cells to cell phone radiation at typical frequencies for 30 minutes to 1 hour. The extremely weak signals - 200 times below safety limits - triggered DNA packaging changes resembling heat stress in most subjects, suggesting cellular effects from everyday phone use.
