Unknown authors · 2008
Researchers exposed murine L929 fibroblasts to 872 MHz continuous wave or pulse modulated RF radiation at 5 W/kg. They measured ornithine decarboxylase activity after 1- and 24-hour exposures, proliferation during 48 hours after 24-hour exposure, and caspase-3 activity after 1-hour exposure. The cells responded to fresh medium and serum deprivation, but no consistent effects of RF radiation were found. One statistically significant difference in ODC activity (p=0.03) was observed but considered a chance finding due to multiple comparisons and lack of support from other data. The results did not support effects on the endpoints studied, and stressed or stimulated cells were not more sensitive than normal cells to RF radiation.
Unknown authors · 2008
Finnish researchers exposed mouse fibroblasts to 872 MHz radiofrequency radiation at 5 W/kg to test whether cell stress affects EMF sensitivity. They measured cell growth, death signals, and enzyme activity under normal, stimulated, and stressed conditions. No consistent biological effects were found from the RF exposure, regardless of the cells' physiological state.
Mathur R. · 2008
Researchers exposed growing rats to a radiofrequency field (73.5 MHz amplitude modulated, 16 Hz, SAR = 0.4 w/kg) for 45 days at 2 hours per day and recorded their responses to several types of noxious stimuli. The tonic pain rating was also decreased (p < 0.01), which the researchers said indicates analgesia in response to tonic pain. The data suggest that amplitude modulated RF field differentially affects the mechanisms involved in the processing of various noxious stimuli.
Mathur R · 2008
Researchers exposed growing rats to AM radio frequency fields (similar to some communication systems) for 2 hours daily over 45 days and tested their pain responses. The exposed rats showed altered pain processing - they became more emotionally reactive to short-term pain but less sensitive to long-term pain. This suggests that chronic RF exposure during development can rewire how the nervous system processes different types of pain signals.
Ross ML, Koren SA, Persinger MA. · 2008
Researchers tested whether a weak magnetic field pulsed over the left prefrontal brain region at the moment of accepting or refuting a statement could increase the likelihood of later accepting a false statement as true. Fifty men and women were each exposed to one of four magnetic field conditions, or a sham field, over the left prefrontal region above the eyebrow. Groups that received the burst-firing or 25 Hz pulsed fields during the refutation process accepted about twice the number of false statements as true compared to those in the 50 Hz or sham-field conditions. The treatments did not significantly affect the numbers of true statements accepted as false.
Lee JJ et al. · 2008
NIH3T3 mouse fibroblasts were exposed to 849 MHz RF radiation at average SAR values of 2 or 10 W/kg for either 1 hour or 1 hour per day for 3 days. Cellular invasion and migration were assessed using in vitro Matrigel invasion and Transwell migration assays. Cell cycle distribution was analyzed at 24 and 48 hours after exposure by flow cytometry. The study found no detectable effects on cell cycle distribution, cellular migration, or invasion at the tested SAR values.
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.
Kumar V, Vats RP, Pathak PP. · 2008
The study examined effects of electromagnetic waves at 41 and 202 MHz from a TV tower on human skin, muscles, bone, and fat. Researchers used international SAR exposure limits to calculate safe distances from TV transmission towers for both frequencies. The authors recommended that transmission towers be located away from densely populated areas and that people keep away from towers because they emit radiation harmful to some body tissues.
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).
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.
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.
