Ozguner F, Bardak Y, Comlekci S. · 2006
Researchers compared how well melatonin and caffeic acid phenethyl ester (CAPE) protected rat retinas from oxidative stress caused by exposure to 900 MHz mobile-phone radiation. Melatonin and CAPE were administered daily for 60 days to the rats prior to their EMR exposure. Retinal levels of the oxidative stress markers NO and MDA increased in EMR-exposed rats, while both melatonin and CAPE caused a significant reduction in those levels. Antioxidant enzyme activities (SOD, GSH-Px, and CAT) decreased in EMR-exposed animals, but both treatments significantly increased those activities.
Ozguner F, Bardak Y, Comlekci S · 2006
Researchers exposed rats to 900 MHz mobile phone radiation (the same frequency used by many cell phones) for 60 days and found it caused significant oxidative stress in eye tissue. The radiation increased harmful compounds and decreased protective antioxidant enzymes in the retina. However, rats given melatonin or caffeic acid supplements before exposure were largely protected from this damage, suggesting these antioxidants might help shield eye tissue from cell phone radiation effects.
Nylund R, Leszczynski D. · 2006
Researchers examined in vitro cell response to mobile phone radiation using two variants of a human endothelial cell line: EA.hy926 and EA.hy926v1. Gene expression changes were examined using cDNA Expression Arrays and protein expression changes were examined using 2-DE and PDQuest software. Gene and protein expression were altered in both examined cell lines after one hour of exposure at an average specific absorption rate of 2.8 W/kg, but the same genes and proteins were differently affected in each line.
Nylund R, Leszczynski D · 2006
Finnish researchers exposed human blood vessel cells to mobile phone radiation for one hour and found that genes and proteins changed differently in each cell type. This suggests that cellular response to phone radiation depends on the specific genetic makeup of cells, potentially explaining conflicting research results.
Oral B et al. · 2006
Researchers examined oxidative stress from a 900-MHz mobile phone and the possible protective effects of vitamins E and C on endometrial tissue in rats. Rats were divided into a sham control group, a 900-MHz EMF-exposed group (30 minutes daily for 30 days), and an EMF-exposed group treated with vitamins E and C before each exposure. Malondialdehyde, a marker of lipid peroxidation, and the proteins Bcl-2, Bax, caspase-3, and caspase-8 were measured in endometrial tissue. The EMF-exposed rats showed increased malondialdehyde levels and apoptosis, while vitamins E and C ameliorated oxidative tissue injury and apoptosis through free radical scavenging and antioxidant properties.
Oral B et al. · 2006
Turkish researchers exposed female rats to 900-MHz radiation (similar to older cell phones) for 30 minutes daily over 30 days and found it caused cell death and oxidative damage in the endometrium, the tissue lining the uterus. However, when rats were given vitamins E and C before exposure, these protective antioxidants significantly reduced the harmful effects. This suggests that cell phone radiation may damage reproductive tissues through oxidative stress, but antioxidants might offer some protection.
Christ A, Samaras T, Klingenböck A, Kuster N. · 2006
The study investigated electromagnetic near-field absorption in layered biological tissue from 30 MHz to 6000 MHz. Two effects can increase SAR in layered tissue versus homogeneous liquid: standing wave effects at larger distances depending on frequency and fat thickness, and high local skin absorption from reactive E-fields in the very close near-field. A conservative exposure estimate can be obtained by applying a multiplication factor of 1 to 3 to current dosimetric values.
Unknown authors · 2006
PMA treatment significantly increased ROS production in both cell types compared to sham or incubator controls. GSM-DTX exposure showed significantly different ROS production in monocytes compared to sham, but this was due to lowered ROS release during sham exposure. No ROS differences were detected in lymphocytes compared to sham or incubator control. Hsp70 expression in monocytes at 0, 1, and 2 hours post-exposure to GSM-DTX at 2 W/kg for 1 hour did not differ from incubator or sham controls.
Yurekli AI et al. · 2006
Researchers used a gigahertz transverse electromagnetic (GTEM) cell to expose rats to electromagnetic fields at the GSM base transceiver station frequency of 945 MHz. The power density applied was 3.67 W/m2 (specific absorption rate = 11.3 mW/kg), which the researchers described as well below current exposure limits. MDA levels increased and GSH concentrations decreased significantly (p < 0.0001) under this exposure. There was also a less significant (p = 0.0190) increase in SOD (superoxide dismutase) activity under EM exposure.
Forgacs Z et al. · 2006
Researchers studied the possible effects of whole-body 1800 MHz GSM-like microwave exposure on male reproduction in mice. After repeated exposure at 0.018-0.023 W/kg SAR, an elevated serum testosterone level was measured, but no histopathological alteration could be detected in the reproductive organs. Leydig cell cultures from exposed animals did not differ from controls in their steroidogenic response.
Xu S, Ning W, Xu Z, Zhou S, Chiang H, Luo J. · 2006
The study assessed the effects of microwave exposure on cultured rat hippocampal neurons using whole cell patch-clamp analysis combined with immunocytochemistry. Chronic exposure for 15 minutes per day over 8 days to GSM 1800-MHz microwaves at a SAR of 2.4 W/kg selectively reduced the amplitude of AMPA miniature excitatory postsynaptic currents, while the frequency of AMPA mEPSCs and the amplitude of NMDA mEPSCs did not change. The same exposure decreased the expression of postsynaptic density 95 (PSD95) in the cultured neurons.
Wilen J, Johansson A, Kalezic N, Lyskov E, Sandstrom M · 2006
Researchers investigated the effect of a mobile phone-like radiofrequency electromagnetic field on people who reported subjective symptoms when using mobile phones. Twenty subjects with mobile phone-related symptoms were matched with 20 controls without such symptoms, and each person took part in one true exposure session and one sham exposure session in random order. No significant differences related to radiofrequency exposure conditions were detected. The symptomatic group displayed a shift in low/high frequency ratio towards sympathetic dominance in the autonomous nervous system during tests, regardless of exposure condition.
Wilen J, Johansson A, Kalezic N, Lyskov E, Sandstrom M. · 2006
Swedish researchers exposed 20 people who experience symptoms from mobile phones and 20 people without symptoms to 900 MHz cell phone radiation for 30 minutes at levels typical of phone use. While the radiation didn't cause immediate measurable changes in either group, the symptomatic individuals showed different nervous system patterns during cognitive tests, suggesting their autonomic nervous systems may function differently regardless of radiation exposure.
Lantow M, Schuderer J, Hartwig C, Simko M. · 2006
Researchers exposed human immune cells to cell phone radiation at 1800 MHz (the frequency used by GSM networks) to see if it would trigger the production of harmful free radicals or stress proteins. Even at high exposure levels up to 2.0 W/kg, the radiation did not cause any significant increase in free radical production or stress protein expression in the cells. This suggests that cell phone radiation at these levels may not trigger the type of cellular damage that free radicals can cause.
Unknown authors · 2006
Koylu H, Mollaoglu H, Ozguner F, Nazyroglu M, Delibab N. · 2006
Twenty-eight Sprague-Dawley male rats were randomly divided into three groups: sham control, 900-MHz microwave exposure, and microwave exposure with melatonin treatment. Microwave exposure increased lipid peroxidation in both the brain cortex and hippocampus compared to controls. Melatonin administration decreased lipid peroxidation in the hippocampus but did not affect cortex levels.
Eliyahu I et al. · 2006
Thirty-six healthy right-handed men performed four cognitive tasks under right-side, left-side, and sham exposure conditions. The study used a standard GSM phone at 890 MHz operated at full power via a base station simulator. Left-side exposure slowed left-hand response time in the later experimental period, an effect seen in three of four tasks but highly significant in only one. The exposure intensity and duration exceeded typical cell phone user exposure.
Hamblin DL, Croft RJ, Wood AW, Stough C, Spong J. · 2006
Researchers tested 120 participants in a double-blind, counterbalanced, crossover design with two sessions one week apart. In both sessions, participants performed auditory and visual oddball tasks while EEG was recorded with a mobile phone set to sham exposure mounted over the temporal region, and then performed the same tasks while the handset was set to active or sham. No significant differences were found between exposure conditions for any ERP component or reaction time.
Henderson SI, Bangay MJ. · 2006
Researchers measured radiofrequency signals from 60 base stations across five Australian cities at distances ranging from 50 to 500 m. All recorded exposure levels were well below the general public exposure limits of the ICNIRP guidelines and the Australian radiofrequency standard (ARPANSA RPS3). The highest level recorded from any single base station was 7.8 x 10(-3) W/m(2), which translates to 0.2% of the general public exposure limit.
Keshvari J, Keshvari R, Lang S. · 2006
Stronati L et al. · 2006
The study used alkaline comet assay, metaphase analysis, micronucleus test, and nuclear division index to assess DNA strand breaks, chromosomal aberrations, sister chromatid exchanges, micronuclei, and cell cycling speed. It comprehensively examined whether 24-hour continuous exposure to a 935 MHz GSM signal at 1 or 2 W/kg is genotoxic per se or can influence x-ray genotoxicity. Within the experimental parameters, no effect from the RFR signal was observed in any instance. The SAR values chosen were near the upper limit of energy absorption in localized tissue during cellular telephone use.
Stronati L et al. · 2006
Italian and British researchers exposed human immune cells (lymphocytes) to 935 MHz cell phone radiation for 24 hours at levels similar to what tissues experience during phone use. Using multiple DNA damage tests, they found no genetic damage from the radiation alone, and the radiation didn't make X-ray damage worse. This suggests that 24-hour exposure to this type of cell phone radiation doesn't directly break DNA or interfere with DNA repair.
Unknown authors · 2006
Researchers exposed two human cell lines, neuronal SK-N-SH and monocytoid U937, to a 900 MHz RF signal pulsed at 217 Hz with a SAR of 0.2 W/kg. For SK-N-SH cells, they assessed effects using gene microarray, real-time PCR, Western blot for heat shock proteins, and flow cytometry for cell cycle and apoptosis. For U937 cells, they assessed effects using cell viability and cell cycle analysis. No significant difference was found between sham-exposed and radiofrequency-exposed cells in any assay or condition.
Sakuma N et al. · 2006
Researchers conducted a large-scale in vitro study to test whether modulated RF fields from mobile radio base stations act as a DNA damaging agent. Human glioblastoma A172 cells and normal human IMR-90 fibroblasts were exposed to 2.1425 GHz CW and W-CDMA radiation. A172 cells were exposed to W-CDMA at SARs of 80, 250, and 800 mW/kg and CW at 80 mW/kg for 2 and 24 hours, while IMR-90 cells were exposed to both modulations at 80 mW/kg for the same periods. No significant differences in DNA strand breaks were observed between exposed groups and sham controls using alkaline comet assays. The authors concluded that low-level exposures do not act as a genotoxicant up to a SAR of 800 mW/kg.
Merola P et al. · 2006
The study examined whether a modulated 900 MHz radiofrequency field at a specific absorption rate higher than the ICNIRP occupational reference level could alter cell proliferation, differentiation, and apoptosis in a neuroblastoma cell line. Cells were exposed for 24, 48, and 72 hours and tested using WST-I assay, molecular markers, caspase activation, and PARP cleavage detection. Combined exposures with retinoic acid and camptothecin were also tested to check for interference between the field and chemical agents. Overall, the data suggest that 900 MHz radiofrequency exposure up to 72 hours does not induce significant alterations in the three principal cell activities.
