Yan JG, Agresti M, Zhang LL, Yan Y, Matloub HS. · 2008
Researchers exposed adult Sprague-Dawley rats to cell phones for 6 hours per day for 126 days and measured mRNA levels of several injury-associated proteins in the brain. The proteins evaluated included Calcium ATPase, Neural Cell Adhesion Molecule, Neural Growth Factor, and Vascular Endothelial Growth Factor. The results showed statistically significant mRNA up-regulation of these proteins in the brains of exposed rats.
Lee KS, Choi JS, Hong SY, Son TH, Yu K. · 2008
Researchers studied biological effects of mobile phone 835 MHz electromagnetic fields in Drosophila at SAR 1.6 W/kg and SAR 4.0 W/kg. At SAR 1.6 W/kg, more than 90% of flies remained viable even after the 30 h exposure, while at SAR 4.0 W/kg viability dropped from the 12 h exposure. Both exposure levels triggered a stress response, increased reactive oxygen species production, and activated ERK and JNK signaling, but not p38 kinase signaling. SAR 4.0 W/kg strongly activated JNK signaling, expression of apoptotic genes, and amplified the number of apoptotic cells in the fly brain.
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.
Wu W, Yao K, Wang KJ, Lu DQ, He JL, Xu LH, Sun WJ. · 2008
Researchers used the DCFH-DA method and comet assay to detect intracellular reactive oxygen species (ROS) and DNA damage in cultured human lens epithelial cells exposed to 4 W/kg 1800 MHz mobile phone radiation or 2 muT electromagnetic noise, or both, for 24 hours intermittently. 1800 MHz mobile phone radiation at 4 W/kg for 24 hours significantly increased intracellular ROS and DNA damage (P<0.05). When electromagnetic noise was added alongside the mobile phone radiation, ROS levels and DNA damage were not significantly elevated compared to sham exposure (P>0.05).
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.
Jia F, Ushiyama A, Masuda H, Lawlor GF, Ohkubo C. · 2007
Researchers measured local temperature changes in rabbit pinnae during 20-minute RF exposures at SAR levels of 0, 2.3, 10.0, and 34.3 W/kg under normal blood flow and without blood flow. Blood flow significantly suppressed temperature increases even at 34.3 W/kg, while 2.3 and 10.0 W/kg did not induce significant temperature rises under normal blood flow conditions. However, 2.3 W/kg induced local skin temperature elevation when blood flow was absent. The authors concluded that physiological blood flow effects should be considered when extrapolating modeling data to living animals.
Eltiti S et al. · 2007
Fifty-six self-reported sensitive and 120 control participants were tested in an open provocation test, of which 12 sensitive and 6 controls withdrew after the first session, and the remainder completed a series of double-blind tests. During the open provocation, sensitive individuals reported lower levels of well-being in both GSM and UMTS compared with sham exposure, whereas controls reported more symptoms during the UMTS exposure. During double-blind tests the GSM signal did not have any effect on either group. Sensitive participants reported elevated levels of arousal during the UMTS condition, whereas the number or severity of symptoms experienced did not increase. Physiological measures did not differ across the three exposure conditions for either group.
Platano D et al. · 2007
Researchers studied the non-thermal effects of radiofrequency electromagnetic fields on barium currents through voltage-gated calcium channels in primary cultures of rat cortical neurons using the patch-clamp technique. Neurons were exposed for one to three periods of 90 seconds to 900 MHz continuous wave or GSM-modulated signals during whole-cell recording at specific absorption rates of 2 W/kg for both modulation types. Single or multiple acute exposures to either continuous wave or GSM-modulated 900 MHz fields did not significantly alter the current amplitude or the current-voltage relationship through voltage-gated calcium channels.
Hirose H et al. · 2007
Researchers performed an in vitro study of low-level RF fields from IMT-2000 base stations to test if modulated signals cause hsp27 phosphorylation and overexpression. No significant differences in phosphorylated hsp27 at serine 82 or in hsp gene expression were found between exposed and sham-exposed groups.
Hallberg O. · 2007
Researchers related health parameters to population density in 21 Swedish counties and to estimates of average mobile phone output power. People in sparsely populated counties in Sweden, Denmark, and Norway have suffered more illness and longer recovery since 1997, whereas the countryside was the healthiest place 20 years ago. The strongest correlations with decreased health quality were estimated average mobile phone power output (positive correlation) and GSM base station coverage (negative correlation) in each county.
Bornkessel C, Schubert M, Wuschek M, Schmidt P. · 2007
The paper summarizes two studies that developed and applied measurement and calculation methods for public exposure around GSM and UMTS base stations. Measurements showed exposures from 0.01% to more than 10% of field strength limits, with distance not a main factor but orientation and sight conditions greatly influencing exposure. Simulation tools predicted exposure accurately in line-of-sight scenarios but free space models overestimated exposure by orders of magnitude in non-line-of-sight situations.
Alanko T, Hietanen M · 2007
Researchers assessed worker exposure to radiofrequency fields in two medium-sized antenna towers. The towers had transmitting antennas from mobile phone networks, radio, digital TV sub-stations, and amateur radio. Measurements were taken close to the tower ladders. All measured values were below ICNIRP occupational reference levels.
Guney M, Ozguner F, Oral B, Karahan N, Mungan T. · 2007
Rats were randomly assigned to four groups of eight each, including a control, a sham, a 900 MHz EMR exposure group, and an EMR plus vitamins E and C group, and the EMR groups received 30 minutes per day for 30 days. EMR exposure increased endometrial nitric oxide and malondialdehyde levels and decreased superoxide dismutase, catalase, and glutathione peroxidase activities, while combined vitamins E and C reversed these changes. The EMR group showed diffuse severe apoptosis in endometrial epithelial, glandular, and stromal cells and diffuse eosinophilic leucocyte and lymphocyte infiltration, which were significantly reduced by vitamins E and C.
Tkalec M, Malarić K, Pevalek-Kozlina B. · 2007
Researchers exposed duckweed (Lemna minor) to radiofrequency electromagnetic fields at 400 and 900 MHz, at field strengths of 10, 23, 41, and 120 V m−1, for 2 hours, and also tested a longer 4-hour exposure and modulated fields. After exposure, the researchers measured lipid peroxidation, H2O2 content, antioxidative enzyme activities and isoenzyme patterns, and HSP70 expression. At 900 MHz, almost all exposure treatments significantly increased lipid peroxidation and H2O2 content, mostly decreased PPX activity, and did not affect CAT activity. No differences in isoenzyme patterns of antioxidative enzymes or HSP70 level were found between control and exposed plants at either frequency.
Buttiglione M et al. · 2007
Researchers exposed human neuroblastoma SH-SY5Y cells to 900 MHz radiofrequency radiation at 1 W/kg to study effects on gene expression and cell-cycle control. Short-term exposures produced a transient increase in Egr-1 mRNA levels along with activation of the MAPK subtypes ERK1/2 and SAPK/JNK. Exposure had an anti-proliferative effect, and a significant G2-M cell-cycle arrest was observed, with signs of apoptosis appearing after 24 hours. A significant decrease in mRNA levels of Bcl-2 and survivin genes, both linked to signaling between G2-M arrest and apoptosis, was also observed.
Whitehead TD, Moros EG, Brownstein BH, Roti Roti JL · 2006
Researchers performed in vitro experiments with C3H 10T(1/2) mouse cells to test whether FDMA or CDMA modulated RF radiation induces changes in gene expression. Cells were exposed to either modulation for 24 h at a specific absorption rate (SAR) of 5 W/ kg. Gene expression was evaluated using the Affymetrix U74Av2 GeneChip to detect changes in mRNA levels. As a positive control, cells were exposed to 0.68 Gy of X rays and gene expression was evaluated 4 h after exposure. For both CDMA and FDMA radiation, the number of probe sets with expression changes greater than 1.3-fold was less than or equal to the expected false positives, indicating no statistically significant effect on gene expression.
Thorlin et al. · 2006
Researchers exposed cultured astroglial and microglial cells to 900 MHz microwave radiation at various SARs and durations. They measured markers including interleukin 6, tumor necrosis factor-alpha, glial fibrillary acidic protein, total protein, and ED-1. No significant differences were found for any parameter at any time or radiation characteristic. Total protein levels remained constant and cell morphology appeared unaffected. The study concluded no evidence for effects on damage-related factors in glial cells.
Sukhotina I, Streckert JR, Bitz AK, Hansen VW, Lerchl A · 2006
Researchers exposed isolated pineal glands from Djungarian hamsters to 1800 MHz continuous wave or GSM-modulated signals at SAR levels of 8, 80, 800, and 2700 mW/kg for 7 hours. At 800 mW/kg SAR both signal types significantly enhanced melatonin release, but at 2700 mW/kg SAR continuous wave elevated melatonin while GSM-modulated exposure suppressed it. The authors concluded that the data do not support the melatonin hypothesis that nonthermal radiofrequency exposure suppresses melatonin synthesis.
Sanchez S et al. · 2006
Researchers exposed five-week-old female hairless rats to GSM-900 or -1800 signals for 2 hours per day, 5 days a week, for 12 weeks. Skin thickness showed no significant difference between exposed and sham-exposed groups. Cellular proliferation measured by Ki-67 remained within normal range in exposed epidermis. Levels of filaggrin, collagen, and elastin did not differ significantly among groups.
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.
Masuda H et al. · 2006
Researchers exposed hairless female rats to GSM-900 or -1800 signals for 2 hours using a loop antenna on the back. The local specific absorption rate at skin level was about 5 W/kg. Skin thickness and cell toxicity did not differ between exposed and sham-exposed rats. Cell proliferation in the epidermis remained within normal range and no proliferation was seen in the dermis. Levels of filaggrin, collagen, and elastin were not significantly affected by the exposure.
Keow MA, Radiman S. · 2006
Researchers measured RF/MW levels emitted by the base stations. Measurements were performed at 200 sites around 47 mobile phone base stations. The RF/MW radiation from these base stations was well below the maximum exposure limits set by various agencies.
Hirose H et al. · 2006
Researchers conducted a large-scale in vitro study to test whether modulated RF fields from mobile radio base stations induce apoptosis or stress responses activating p53. Human glioblastoma A172 cells were exposed to W-CDMA radiation at SARs of 80, 250, and 800 mW/kg and CW radiation at 80 mW/kg for 24 or 48 hours, while human IMR-90 fibroblasts were exposed to both modulations at 80 mW/kg for 28 hours. No significant differences in apoptosis, phosphorylated p53 at serine 15, total p53, or downstream gene expression were found between exposed and sham-exposed cells.
Chauhan V et al. · 2006
Researchers exposed human lymphoblastoma TK6 cells to 1.9 GHz pulse-modulated RF fields at SARs of 1 and 10 W/kg. They assessed expression of proto-oncogenes FOS, JUN, and MYC using real-time RT-PCR. They also monitored transcript levels of the heat-shock proteins HSP27 and inducible HSP70. Transcript levels in RF-exposed cells showed no significant difference compared to sham-exposed cells. Positive heat-shock controls showed significant elevation of HSP27, HSP70, FOS, and JUN, and a decline in MYC mRNA.
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.