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.
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.
Ribeiro EP, Rhoden EL, Horn MM, Rhoden C, Lima LP, Toniolo L · 2007
Researchers randomly divided 16 male Wistar rats into experimental and control groups; the experimental group was exposed to GSM radiofrequency (1,835–1,850 MHz) for 1 hour daily over 11 weeks. They measured rectal temperature, testicular and epididymal weight, lipid peroxidation, serum testosterone, sperm count, and histopathological endpoints. No statistically significant differences were found between exposed and control groups in any measured endpoint.
Chauhan V et al. · 2007
Researchers exposed human-derived cell lines TK6, HL60, and Mono-Mac-6 to intermittent 1.9 GHz pulse-modulated RF fields for 6 hours at SARs of 0, 1, and 10 W/kg. Cell viability, apoptosis, and cell cycle kinetics were measured immediately after exposure and 18 hours later. Cytokine expression (TNFA, IL1B, IL6, IL8, IL10, IL12) was also assessed. No detectable changes in cell viability, cell cycle kinetics, apoptosis, or cytokine expression were observed in any exposed group compared to sham controls. The positive heat-shock control showed decreased viability, increased apoptosis, and a G(2)/M cell cycle block.
Chauhan V et al. · 2007
Researchers examined the effect of RF field exposure on late onset gene expression in U87MG cells after a 24 h exposure period. A human monocyte-derived cell line (MM6) was exposed to intermittent RF fields for 6 h and gene expression was assessed immediately and at 18 h postexposure. Both cell lines were exposed to 1.9 GHz pulse-modulated RF fields for 6 or 24 h at SARs of 0.1-10.0 W/kg. The study found no evidence that nonthermal RF field exposure altered gene expression in either U87MG or MM6 cells relative to nonirradiated controls. Heat shock at 43°C for 1 h altered the expression of well-characterized heat-shock proteins in both cell lines.
Speit G, Schütz P, Hoffmann H. · 2007
Researchers exposed ES1 cells to 1800 MHz RF-EMF at 2 W/kg SAR with intermittent exposure and tested for DNA damage using the alkaline comet assay and micronucleus test. They also tested V79 Chinese hamster cells and found no genotoxic effect in either assay. Quality control measures were used to rule out test performance issues, exposure failure, or evaluation bias.
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.
Yan JG, Agresti M, Bruce T, Yan YH, Granlund A, Matloub HS. · 2007
Rats exposed to 6 hours of daily cellular phone emissions for 18 weeks exhibited a significantly higher incidence of sperm cell death than control group rats through chi-squared analysis. Abnormal clumping of sperm cells was present in exposed rats and absent in controls.
Peyman A, Holden SJ, Watts S, Perrott R, Gabriel C · 2007
The dielectric properties of pig cerebrospinal tissues were measured in vivo and in vitro in the frequency range of 50 MHz-20 GHz. White matter and spinal cord showed significant variation as a function of animal age while no age-related variations were recorded for grey matter. The in vitro study included tissue from pigs weighing approximately 10, 50, and 250 kg to examine variation with age. Total combined measurement uncertainty was calculated at each frequency point and reported over representative frequency regions. Comparisons were made between the in vivo and in vitro data and with literature from the past decade.
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.
Baohong W et al. · 2007
Researchers exposed human lymphocytes to 1.8 GHz microwaves at a SAR of 3 W/kg, ultraviolet ray C (UVC), or both, then measured DNA damage using the comet assay. Microwave exposure alone did not produce significantly more DNA damage than the control group. When combined with UVC, microwave exposure was associated with reduced DNA damage at 1.5-hour incubation but increased DNA damage at 4-hour incubation, compared with UVC alone.
Zeni et al. · 2007
Researchers investigated whether 900 MHz RF radiation could induce reactive oxygen species in murine L929 fibrosarcoma cells, with or without co-exposure to MX, a potent environmental carcinogen produced during chlorination of drinking water. Both continuous-wave and GSM mobile phone signals were applied for 10 or 30 min at specific absorption rates of 0.3 and 1 W/kg. The study found no indication that RF-field exposure, alone or combined with MX, induced reactive oxygen species formation, while MX alone caused a statistically significant increase in reactive oxygen species for all the treatment durations investigated.
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.
Zhao R, Zhang S, Xu Z, Ju L, Lu D, Yao G. · 2007
Researchers investigated whether 1800 MHz radiofrequency electromagnetic fields could influence gene expression in rat neurons. Among 1200 candidate genes, 24 were up-regulated and 10 were down-regulated after 24 hours of intermittent exposure at a SAR of 2 W/kg. The researchers concluded that gene expression in rat neurons could be altered by exposure to radiofrequency electromagnetic fields under their experimental conditions.
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 exposed cultured C3H 10T 1/2 cells to cell phone RF radiation at a specific absorption rate of 5 W/kg for 24 hours. Gene expression was measured using Affymetrix microarrays and compared to sham controls. The RF exposure did not produce more gene expression changes than expected by chance. In contrast, X-ray exposure at 0.68 Gy with a 4-hour recovery produced more changes than the sham comparison.
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.
Wang LL, Chen GD, Lu DQ, Chiang H, Xu ZP. · 2006
Researchers intermittently exposed MCF-7 cells to GSM 1800 MHz RF EMF modulated by 217 Hz for 24 hours at SARs of 2.0 W/kg or 3.5 W/kg. A small number of differentially expressed genes were found after exposure. Reproducible analysis yielded no genes at 2.0 W/kg and five up-regulated genes at 3.5 W/kg. The five genes identified at 3.5 W/kg could not be confirmed by RT-PCR. The authors concluded that the study did not provide clear evidence of distinct gene expression changes under the experimental conditions.
