Unknown authors · 2008
Researchers exposed human lens epithelial cells intermittently for 24 hours to radiofrequency fields at specific absorption rates of 1, 2, 3, and 4 W/kg. DNA damage measured by alkaline comet assay increased significantly at 3 and 4 W/kg, while double-strand breaks increased only at 4 W/kg. Intracellular reactive oxygen species levels rose significantly at 3 and 4 W/kg, and cells exposed to 4 W/kg showed G0/G1 cell cycle arrest. Apoptosis did not differ between exposed and sham groups, and all observed effects were blocked when the radiofrequency field was superposed with 2 muT electromagnetic noise.
Unknown authors · 2008
This 2008 study exposed human eye lens cells to 1.8 GHz cell phone radiation at various power levels for 24 hours. Researchers found DNA damage and cellular stress at higher exposure levels, but discovered that adding electromagnetic 'noise' completely blocked these harmful effects. However, this study was later retracted by the journal.
Zhang SZ, Yao GD, Lu DQ, Chiang H, Xu ZP. · 2008
Researchers exposed primary cultured rat neurons to 1.8 GHz RF EMF at a SAR of 2 W/kg and used a gene array to look for changes in gene expression. Among 1200 candidate genes screened, 24 were up-regulated and 10 were down-regulated, associated with functions including cytoskeleton, signal transduction, and metabolism. The effect of 24-hour exposure on gene expression was more obvious than that of 6-hour exposure, and intermittent exposure had a more obvious effect than continuous exposure.
Zhang SZ, Yao GD, Lu DQ, Chiang H, Xu ZP. · 2008
Researchers exposed rat brain cells to cell phone radiation (1.8 GHz) for up to 24 hours. The radiation altered 34 genes controlling brain cell structure, communication, and metabolism. Changes were stronger with intermittent exposure patterns, suggesting cell phone signals may affect brain function.
Partsvania B, Sulaberidze T, Modebadze Z, Shoshiashvili L. · 2008
Researchers studied how extremely low-frequency magnetic fields at 8.34 and 217 Hz affected the ability of single neurons in the mollusk Helix Pomatia to habituate to repeated stimuli. Brain ganglia were exposed to magnetic fields with peak values between 1 and 6 mT using Helmholtz coils, and neuron activity was recorded with a standard microelectrode technique. Exposure caused dehabituation, which the researchers described as occurring through degradation of the signal to noise ratio and alteration of the neuron's normal function.
Nittby H et al. · 2008
Swedish researchers exposed rats to cell phone radiation at 1,800 MHz for six hours and found significant changes in brain gene expression. The radiation altered genes controlling cell membranes and signal transmission in memory-critical brain regions, occurring at levels similar to extended human cell phone use.
Manti L et al. · 2008
Researchers exposed human peripheral blood lymphocytes in vitro to a UMTS signal at a frequency carrier of 1.95 GHz for 24 hours at 0.5 and 2.0 W/kg SAR. Cells were also given 4 Gy of X rays immediately before RF radiation or sham exposures, and chromosome aberrations were measured by fluorescence in situ hybridization. No significant variations due to the UMTS exposure were found in the fraction of aberrant cells, but the frequency of exchanges per cell showed a small but statistically significant increase of 0.11 exchange per cell compared to 0 W/kg SAR.
Mazor R et al. · 2008
Researchers exposed human peripheral blood lymphocytes from 10 samples to radiofrequency electromagnetic fields at 800 MHz for 72 hours in a waveguide resonator at specific absorption rates of 2.9 and 4.1 W/kg. The study found increased levels of aneuploidy depending on the chromosome studied and the level of exposure, with chromosomal gains appearing to be the primary contributor. Temperature was tested over a range of 33.5–40°C for 72 hours and showed no statistically significant difference in aneuploidy levels compared to 37°C, suggesting the effect may not be due to heating.
Yao K, Wu W, Wang K, Ni S, Ye P, Yu Y, Ye J, Sun L. · 2008
Researchers exposed cultured human lens epithelial cells (HLECs) to a 1.8 GHz GSM radiofrequency field for 2 hours at specific absorption rates of 1, 2, 3, and 4 W/kg, then measured intracellular reactive oxygen species (ROS) and DNA damage. After exposure to 1.8 GHz RF for 2 h, HLECs exhibited significant intracellular ROS increase in the 2, 3, and 4 W/kg groups, and RF at 3 W/kg and 4 W/kg induced significant DNA damage consisting mainly of single strand breaks. When the radiofrequency field was superposed with 2 μT electromagnetic noise, the noise blocked the RF-induced ROS increase and DNA damage.
Ammari M et al. · 2008
Researchers measured GFAP expression in rat brain areas using immunocytochemistry to evaluate glial changes 10 days after chronic exposure to a GSM 900 MHz signal. Rats were exposed 5 days a week for 24 weeks at a brain-averaged SAR of 1.5 W/kg for 45 minutes per day, or at 6 W/kg for 15 minutes per day. Compared with sham or cage control animals, rats exposed at 6 W/kg had increased GFAP stained surface areas (p < 0.05), while exposure at 1.5 W/kg did not increase GFAP expression. The researchers noted that chronic exposure at 6 W/kg may induce persistent astroglia activation in the rat brain, which they described as a sign of a potential gliosis.
Ammari M, Lecomte A, Sakly M, Abdelmelek H, de-Seze R · 2008
Researchers measured cytochrome oxidase levels in rat brains using histochemical methods to evaluate regional brain metabolic activity after GSM 900 MHz signal exposure. Rats were exposed either for 45 minutes per day at a SAR of 1.5 W/Kg or for 15 minutes per day at a SAR of 6 W/Kg, over seven days. At 6 W/Kg, decreased CO activity was found in areas of the prefrontal and frontal cortex, the hippocampus, and the posterior cortex, while exposure at 1.5 W/Kg did not affect brain activity.
Joubert, V., Bourthoumieu, S., Leveque, P. and Yardin, C. · 2008
Researchers exposed rat primary neuronal cultures to a continuous-wave 900 MHz radiofrequency field at a specific absorption rate of 2 W/kg for 24 hours. A statistically significant difference in the rate of apoptosis was found in the RF-field-exposed neurons compared to the sham-, 37°C- and 39°C-exposed neurons either 0 or 24 h after exposure using both methods. The percentage of AIF-positive nuclei in RF-field-exposed neurons was increased by three- to sevenfold compared to other conditions, while no increase in caspase 3 activity was found.
Odaci E, Bas O, Kaplan S · 2008
Researchers investigated the effects of prenatal EMF exposure on the number of granule cells in the dentate gyrus of 4-week-old rats. Pregnant rats in the exposed group were subjected to a 900 MHz EMF for 60 min/day between the first and last days of gestation. The results showed that prenatal EMF exposure caused a decrease in the number of granule cells in the dentate gyrus (P < 0.01).
Ahmed Z, Wieraszko A. · 2008
Researchers investigated the influence of a pulsed magnetic field on hippocampal evoked potentials in vitro. Exposure to a pulsed magnetic field at 0.16 Hz and 15 mT, applied for 30 minutes, amplified the population spike and the slope of EPSP recorded from hippocampal tissue. The amplification was additive to previously induced long-term potentiation and occurred in an NMDA-independent way. The pulsed magnetic field also modified paired-pulse facilitation and paired-pulse inhibition, suggesting it affects both excitatory and inhibitory processes in the hippocampus.
Falone S et al. · 2008
Researchers continuously exposed female Sprague-Dawley rats to a sinusoidal 50 Hz, 0.1 mT magnetic field for 10 days. The study examined antioxidant protection systems and neurotrophic support in brain cortices, as a function of the age of the subjects. Exposure significantly affected antioxidant capability in both young and aged animals, but in opposite ways. The researchers suggested that exposure to these fields may act as a risk factor for oxidative stress-based nervous system pathologies associated with ageing.
Harakawa S et al. · 2008
Researchers examined how a 50 Hz sinusoidal electric field affected the voluntary behavior of Wistar rats using a conditioned place aversion response based on an aversive behavior against light environment. Rats conditioned without the electric field spent significantly less time in the white place, while rats conditioned with the electric field did not show such changes. The researchers considered that the aversion response to the light environment was interfered by exposure to the electric field.
Liu T, Wang S, He L, Ye K. · 2008
The study investigated whether anxiety levels could be affected by repeated extremely low frequency magnetic field (ELF MF) exposure of different daily durations. Rats exposed for 4 h/day showed increased anxiety-like behaviors in the open field test and the elevated plus maze test, without changes in locomotor activity, but showed no effect in the light/dark box test. Rats exposed for 1 h/day showed no effect in any of the tests.
Liu T, Wang S, He L, Ye K. · 2008
Researchers tested spatial learning and memory in rats using the Morris water maze after four weeks of daily exposure to a 50-Hz magnetic field of 2 mT for either one or four hours. Chronic exposure reduced the time rats took to find a hidden platform and improved long-term memory of the platform's former location. Short-term memory and motor activity were not affected.
Wang X et al. · 2008
Researchers exposed rats to extremely low-frequency electromagnetic fields (20 Hz, 14 mT) for one hour per day before daily morphine injections for 12 days, then measured dopamine D2 receptor density in the dorsal hippocampus during withdrawal. Morphine withdrawal alone significantly lowered D2 receptor density compared to saline controls, and ELF-EMF exposure during morphine treatment further reduced receptor density on the first and third withdrawal days. In both groups, D2 receptor density tended to recover as the number of withdrawal days increased.
Canseven AG, Coskun S, Seyhan N · 2008
Researchers exposed guinea pigs to 50 Hz magnetic fields at 1, 2, and 3 mT for 4 h/day and 8 h/day for 5 days, measuring malondialdehyde, nitric oxide, glutathione, and myeloperoxidase activity in heart and liver tissues. MDA levels increased in the liver in some groups but decreased in both liver and heart in group VII. The researchers concluded that field intensity and exposure duration are among the conditions that influence free radical formation and antioxidant enzyme behavior.
Erdal N, Gürgül S, Tamer L, Ayaz L · 2008
Researchers exposed adult Wistar-Albino rats to an extremely low frequency magnetic field (50 Hz, 1 mT, 4 hours per day) to study oxidative and nitrosative stress in liver tissue. 3-nitrotyrosine (3-NT) levels were significantly increased in exposed female rats compared to female controls, but no significant difference was found between exposed and control male rats. Malondialdehyde (MDA) levels showed no significant differences between control and exposed rats in either sex.
Falone S et al. · 2008
Italian researchers exposed young and older rats to 50 Hz magnetic fields from power lines for 10 days. Young rats strengthened their brain's antioxidant defenses, but older rats experienced significant weakening of these protective systems, suggesting aging brains are more vulnerable to EMF damage.
Hashish AH, El-Missiry MA, Abdelkader HI, Abou-Saleh RH · 2008
Ahmed Z, Wieraszko A. · 2008
Researchers exposed brain tissue from the hippocampus (memory center) to pulsed magnetic fields for 30 minutes. The neurons became significantly more electrically active, firing more signals and changing how they communicate. This shows magnetic fields can directly alter brain cell function.
Ammari M et al. · 2008
French researchers exposed rats to cell phone radiation (900 MHz) for 24 weeks and found that high-level exposure caused persistent brain inflammation. The study measured GFAP, a protein that increases when brain support cells called astrocytes become activated in response to injury or stress. This suggests that chronic cell phone radiation exposure may trigger ongoing inflammatory responses in brain tissue.
