Lerchl A et al. · 2008
Researchers exposed adult male Djungarian hamsters to RF-EMF at 383, 900, and 1800 MHz for 60 days at 80 mW/kg. Pineal and serum melatonin levels and organ weights were not affected in any experiment. Body weight increased transiently up to 4% at 383 MHz, increased up to 6% non-transiently at 900 MHz, and was unchanged at 1800 MHz.
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.
Huang TQ et al. · 2008
Researchers exposed HEI-OC1 immortalized mouse auditory hair cells to 1763 MHz RF at 20 W/kg SAR in a CDMA chamber for 24 and 48 hours. They assessed cell cycle, DNA damage, heat shock protein expression, MAPK phosphorylation, and gene expression, finding no changes in cell cycle, DNA damage, HSP expression, or MAPK phosphorylation. Microarray analysis showed only 29 genes (0.09% of total) changed more than 1.5-fold after exposure.
Huang TQ, Lee MS, Oh E, Zhang BT, Seo JS, Park WY. · 2008
They assessed cell proliferation, cell cycle progression, DNA damage, and gene expression. RF exposure did not significantly change cell numbers, cell cycle distribution, or DNA damage levels. Genome-wide analysis found no genes changed more than two-fold, but ten genes changed 1.3- to 1.8-fold, including down-regulation of CXCR3 and IL1R2.
Hirose H et al. · 2008
Researchers continuously exposed BALB/3T3 cells to 2.1425 GHz W-CDMA RF fields at SARs of 80 and 800 mW/kg for 6 weeks. They also tested MCA-treated cells and MCA plus TPA-treated cells for tumor promotion and co-promotion effects. No significant differences in transformation frequency were found between RF-exposed groups and sham-exposed controls in any treatment condition. The results suggest that exposure to low-level RF radiation of up to 800 mW/kg does not induce cell transformation.
Kim TH et al. · 2008
Researchers used a carousel-type chamber to expose the heads of C57BL mice to 849 MHz or 1763 MHz RF radiation. Mice were irradiated intermittently at 7.8 W/kg for up to 12 months. Brain tissues collected at 6 and 12 months showed no differences in histology, cell proliferation, NeuN and GFAP expression in hippocampus and cerebellum, or cell death between exposure and control groups. Body weights did not differ among sham, 849 MHz, and 1763 MHz groups during the study.
Roux D et al. · 2008
Researchers investigated the role of extracellular ATP in plant responses to high-frequency, low-amplitude electromagnetic fields. Exposure to low-level 900 MHz EMF evoked accumulation of stress-related transcripts and affected ATP levels. ATP concentration dropped 27% after 30 minutes of exposure, and adenylate energy charge decreased by 18%. The authors discuss whether this reflects increased energy usage or a signaling function for ATP in stress physiology.
Engelmann JC et al. · 2008
Researchers exposed Arabidopsis thaliana cell suspension cultures to a radiofrequency field protocol representing typical urban microwave exposure for 24 hours. They used Affymetrix-ATH1 whole genome microarrays to measure gene expression. Differential expression analysis revealed significant changes in transcription of 10 genes, but fold changes did not exceed 2.5. Three of the affected genes are dark-inducible, and their functions do not point to known plant responses to environmental stimuli.
Tiwari R et al. · 2008
Researchers exposed whole blood samples from six healthy men to RF signals from a CDMA mobile phone for one hour. They assessed DNA damage using the alkaline comet assay and tested combinative effects with aphidicolin at two concentrations. RF signals alone or with low-dose aphidicolin did not significantly increase DNA damage compared to sham exposure. However, univariate analysis showed significant DNA damage with combined exposure at both aphidicolin concentrations. APC alone at the higher concentration also caused significant damage, and DNA repair efficiency varied significantly in combined exposure groups.
Kim JY et al. · 2008
The study investigated clastogenicity of 835-MHz RF-EMF using alkaline comet assay and chromosomal aberration test on mammalian cells. No direct cytogenetic effect was found in the chromosomal aberration test with RF-EMF alone. The comet assay showed nearly negative results for RF-EMF alone, with a small increase in tail moment. RF-EMF showed a potentiation effect in the comet assay when combined with model clastogens.
Zeni O et al. · 2008
Roux D et al. · 2008
Researchers exposed tomato plants to 900 MHz, 5 V m(-1) electromagnetic fields for 10 minutes using a Mode Stirred Reverberation Chamber. Within minutes, stress-related mRNAs for calmodulin, calcium-dependent protein kinase, and proteinase inhibitor accumulated in a rapid, large, three-phase pattern typical of an environmental stress response. Transcript accumulation was maximal at normal calcium levels, depressed at higher calcium, and completely suppressed when calcium was removed with chelators or channel blockers. Thirty minutes after exposure, ATP concentration and adenylate energy charge transiently decreased, and the uncoupler CCCP prevented transcript accumulation entirely.
Rao VS et al. · 2008
The study used neuronal cells differentiated from a mouse embryonic stem cell line and a frequency-tunable applicator to examine calcium dynamics in real time. Control cells showed about five spontaneous calcium spikes per cell in 60 minutes, while exposure to 800 MHz RF radiation at 0.5 W/kg increased spikes to 15.7 per cell. The increase depended on frequency but not on SAR between 0.5 and 5 W/kg, and involved N-type calcium channels and phospholipase C enzymes. Microfilament disruption prevented the calcium spikes.
Pavicic I, Trosic I · 2008
Researchers exposed V79 cells to continuous wave frequencies of 864 MHz and 935 MHz for 1, 2, or 3 hours. Growth was significantly increased after two- and three-hour exposures to 864 MHz and after three-hour exposure to 935 MHz, measured 72 hours after irradiation. Colony-forming ability and cell viability did not significantly differ from control cells. The two fields showed similar effects on growth, colony-forming ability, and viability, with impact being time-dependent.
Palumbo R et al. · 2008
The study investigated apoptosis induction after 900 MHz GSM radiation by measuring caspase 3 activation in Jurkat cells and quiescent and proliferating human peripheral blood lymphocytes. Exposure was at 1.35 W/kg for one hour in a temperature-controlled dual wire patch cell system. Caspase 3 activity increased by 32.4% in Jurkat cells and 22% in proliferating lymphocytes 6 hours after exposure, but did not change in quiescent lymphocytes. Apoptosis and viability assessed 24 hours later were unaffected in both cell types. Cell cycle analysis of proliferating T cells also showed no differences between exposed and sham-exposed cultures.
Millenbaugh NJ et al. · 2008
Rats were exposed to 35 GHz millimeter waves at 75 mW/cm(2), 42 degrees C heat, or sham, with skin collected at 6 and 24 h for gene expression and at 3-6 h or 24-48 h for histopathology. Microscopic examination showed neutrophil aggregation in vessels, stromal cell degeneration, and collagen breakdown in the dermis of exposed rats. Changes were detected in 56 genes at 6 h and 58 genes at 24 h in millimeter-wave-exposed rats. Affected genes included those for transcription regulation, protein folding, oxidative stress, immune response, and tissue matrix turnover at both times, with more extracellular matrix and chemokine genes altered at 24 h. Real-time RT-PCR confirmed up-regulation of Hspa1a, Timp1, S100a9, Ccl2, and Angptl4 at 24 h.
Karinen A, Heinavaara S, Nylund R, Leszczynski D. · 2008
Researchers exposed a small area of forearm skin in 10 female volunteers to RF-EMF at a specific absorption rate of 1.3 W/kg and collected punch biopsies from exposed and non-exposed areas. Analysis identified 8 proteins that were statistically significantly affected, and two of those proteins were present in all 10 volunteers. The researchers described this as the first study showing that molecular level changes might take place in human volunteers in response to exposure to RF-EMF.
Höytö A, Luukkonen J, Juutilainen J, Naarala J. · 2008
Researchers exposed human SH-SY5Y neuroblastoma and mouse L929 fibroblast cells to 872 MHz radiofrequency radiation at a specific absorption rate of 5 W/kg, using either continuous waves or a GSM-modulated signal. Two statistically significant differences related to RF radiation were found: t-BOOH-induced lipid peroxidation was increased in SH-SY5Y cells, and menadione-induced caspase 3 activity was increased in L929 cells, but both only for the GSM-modulated signal. No other endpoints were significantly affected, and no effects were observed from RF radiation exposure alone.
Dawe AS et al. · 2008
Researchers exposed a transgenic strain of the nematode C. elegans to radiofrequency fields at 1.8 GHz and a specific absorption rate of approximately 1.8 W/kg. For both continuous wave and Talk-pulsed exposures lasting 2.5 hours, there was no indication that RF exposure could induce reporter expression above sham control levels. When background reporter expression was moderately elevated in sham controls, the researchers found some evidence that reporter expression may be reduced by approximately 15% following exposure to either Talk-pulsed or CW RF fields.
Aly AA et al. · 2008
Researchers studied how 900-MHz radio-frequency fields affect the ability of human neutrophils to follow concentration gradients of Cyclic Adenosine 3', 5'-Monophosphate (C-AMP). Blood from healthy adult donors was exposed in vitro to different temperatures and a 900-MHz RF field at approximately 0.4 V/m. When the 900-MHz RF field was applied, neutrophil speed increased above the value observed at the same temperature, and the maximum speed exceeded that measured at any temperature by approximately 50%. The direction of motion changed from along the concentration gradient and the electrical field lines to motion at right angles to the concentration gradient and the electric field.
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.
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.
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.
Schwarz C et al. · 2008
Researchers exposed human cultured fibroblasts and human lymphocyte cultures to 1,950 MHz UMTS electromagnetic fields at specific absorption rates below the safety limit of 2 W/kg. UMTS exposure increased the comet tail factor and induced centromere-negative micronuclei in human cultured fibroblasts in a dose- and time-dependent way. Incubation for 24 hours at a SAR of 0.05 W/kg produced a statistically significant rise in both the comet tail factor and micronuclei (P = 0.02). No UMTS effect was found in lymphocytes, whether unstimulated or stimulated with Phytohemagglutinin. The researchers concluded that UMTS exposure may cause genetic alterations in some but not in all human cells in vitro.
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.
