Unknown authors · 2008
Researchers present a model of slow non-uniform rotation of the charged nucleoid for combined effects of microwaves and static magnetic field. The model suggests that combined action results in slow non-uniform rotation of the nucleoid with angular speed depending on Larmor frequency. The model also predicts that non-thermal effects of microwaves depend on carrier frequency and static magnetic field in the exposure area.
Unknown authors · 2008
Since 1999, multiple studies used high-throughput screening to examine genome-wide and proteome-wide responses to RF fields similar to mobile phones. The review concluded that results are still inconclusive because most positive reports have methodological flaws. No precise, reproducible response pattern was identified when positive findings were reported. HTST studies tend to exclude a cell stressor role for RF fields at nonthermal intensities.
Valbonesi P et al. · 2008
Researchers used the human trophoblast cell line HTR-8/SVneo to evaluate HSP70 and HSC70 protein and gene expression and primary DNA damage after nonthermal exposure to pulse-modulated 1817 MHz GSM-217 Hz waves for one hour at a SAR of 2 W/kg. Heat shock significantly enhanced HSP70 expression but not HSC70 expression. Exposure to high-frequency EMFs did not change HSP70 or HSC70 protein or gene expression. Hydrogen peroxide caused a significant increase in DNA strand breaks, but EMF exposure did not. Overall, no evidence was found that the exposure induced a HSP70-mediated stress response or primary DNA damage.
Prisco MG et al. · 2008
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.
Paparini A et al. · 2008
Mice were exposed to GSM 1800 MHz signal for 1 hour at a whole body SAR of 1.1 W/kg. Gene expression was measured in whole brain using microarrays with over 22,600 probe sets. Comparison of sham and exposed animals showed no significant difference in gene expression. With less stringent analysis, 75 genes appeared modulated but were not confirmed by real-time PCR.
Yadav AS, Sharma MK. · 2008
Researchers studied 109 subjects, 85 regular mobile phone users and 24 non-users, collecting exfoliated buccal cells and screening 1000 cells per person for nuclear anomalies. Exposed users averaged 61.26 minutes daily and 2.35 years of use, and had significantly higher micronucleated cell counts than controls. Karyorrhexis, broken egg, and binucleated cell frequencies were slightly higher in exposed subjects but not statistically significant.
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.
Chen ZJ, He JL. · 2008
The study aimed to investigate mutagenic, carcinogenic, and teratogenic effects induced by radiofrequency electromagnetic fields from mobile phones. The authors noted that conflicting results exist in publications on these effects. They reported that overwhelming findings do not support the assumption that RF exposure may induce mutagenic, carcinogenic, or teratogenic effects. However, they stated that health effects from low-level RF exposure need further study.
Baste V, Riise T, Moen BE. · 2008
Researchers conducted a cross-sectional study among 10,497 military men in the Royal Norwegian Navy to assess work near radiofrequency-emitting equipment, infertility, and offspring sex ratio. Infertility increased significantly with increasing self-reported exposure to radiofrequency electromagnetic fields. Adjusted odds ratios for infertility were 1.39 for low exposure, 1.52 for some exposure, 1.93 for high exposure, and 1.86 for very high exposure compared to no exposure. Higher paternal exposure was also associated with a lower ratio of boys to girls at birth. The number of children was not associated with exposure degree.
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.
Fitzsimmons RJ, Gordon SL, Kronberg J, Ganey T, Pilla AA. · 2008
Researchers tested whether a pulsing electric field could directly affect chondrocytes in vitro. A 30-minute PEF treatment increased DNA content of chondrocyte monolayers by approximately 150% at 72 hours poststimulus. The PEF signal increased nitric oxide in the culture medium and cGMP in cell extracts within the 30-minute exposure period. The calcium/calmodulin inhibitor W7 prevented the PEF-stimulated increases in nitric oxide and cGMP; the nitric oxide synthase inhibitor L-NAME prevented increases in nitric oxide, cGMP, and DNA content; and the guanylate cyclase inhibitor LY83583 blocked increases in cGMP and DNA content. A nitric oxide donor present for only 30 minutes increased DNA content at 72 hours.
Zeni O et al. · 2008
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.
Yokus B, Akdag MZ, Dasdag S, Cakir DU, Kizil M · 2008
Levels of FapyAde, FapyGua, and 8OHdG were increased at both intensities compared to cage-control and sham groups, but statistical significance was observed only in the group exposed to 100 μT. The researchers noted that the intensity of ELF-MF has an important influence on the extent of DNA damage.
Koyama S, Sakurai T, Nakahara T, Miyakoshi J · 2008
Researchers measured apurinic/apyrimidinic (AP) sites in human glioma A172 cells after exposure to extremely low frequency (ELF) magnetic fields, genotoxic chemicals, or both. ELF magnetic fields alone produced no difference in AP sites compared with sham controls. The results suggest that the number of AP sites induced by MMS or H2O2 is enhanced by exposure to ELF magnetic fields at 5 millitesla (mT).
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.
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).
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.
Nittby H et al. · 2008
Researchers exposed Fischer 344 rats to radiation from a GSM mobile test phone at 1,800 MHz for 6 hours and then analyzed gene expression in the cortex and hippocampus. Four rats were exposed in an anechoic chamber one at a time, and four control rats were kept in the same chamber for the same duration without exposure. Gene ontology analysis found highly significant changes in gene categories related to membrane functions in both brain regions.
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.
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.
