Dimbylow P. · 2007
Researchers used finite-difference time-domain calculations to estimate SAR from 20 MHz to 3 GHz in hybrid voxel-mathematical models of the pregnant female. Mathematical models of the developing foetus at 8-, 13-, 26- and 38-week gestation were converted into voxels and combined with the reference adult female model, NAOMI at a resolution of 2 mm. The study calculated the electric field values needed to produce the ICNIRP public exposure restriction of 2 W kg(-1) when averaged over 10 g of the foetus.
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.
Capri M et al. · 2006
Researchers exposed human peripheral blood mononuclear cells from young and elderly donors to radiofrequency radiation at 1,800 MHz and a Specific Absorption Rate of 2 W/kg, with or without mitogenic stimulation. However, RF exposure produced a slight but significant downregulation of CD95 expression in stimulated CD4+ T lymphocytes from elderly donors only.
Joubert V et al. · 2006
Researchers exposed human neuroblastoma SH-SY5Y cells to GSM-900 at 0.25 W/kg average SAR or continuous-wave 900 MHz at 2 W/kg SAR for 24 hours. No statistically significant difference in apoptosis rate was found between sham-exposed and microwave-exposed cells at either 0 or 24 hours post-exposure. Apoptosis rates were also comparable between sham, continuous-wave, 37°C, and 39°C exposed cells. Three assessment methods including DAPI staining, TUNEL/PI flow cytometry, and caspase-3 fluorimetry gave concordant results.
Lee JS, Huang TQ, Kim TH, Kim JY, Kim HJ, Pack JK, Seo JS. · 2006
Researchers exposed human T-lymphocyte Jurkat cells and rat primary astrocytes to 1763 MHz RF radiation at SARs of 2 or 20 W/kg for 30 minutes or 1 hour while temperature was completely controlled at 37 +/- 0.2 degrees C. No detectable difference was observed in the expression levels of HSP90, HSP70, and HSP27, and the phosphorylation status of MAPKs did not change significantly. When TPA alone was applied, MAPKs were phosphorylated in a dose-dependent manner, but RF radiation did not enhance TPA-induced MAPK phosphorylation, and neither TPA nor RF radiation affected HSP induction.
Lantow M, Viergutz T, Weiss DG, Simko M. · 2006
Researchers used human Mono Mac 6 cells and exposed them to a 1,800 MHz GSM-DTX signal at 2 W/kg SAR for 12 hours. They measured cell cycle kinetics, BrdU uptake, apoptosis, and necrosis using flow cytometry. No statistically significant differences were found in apoptosis, necrosis, cell cycle kinetics, or BrdU uptake between RF EMF-exposed cells and sham or incubator controls. Positive controls treated with gliotoxin and PMA showed significant increases in apoptosis and necrosis, and PMA caused a significant accumulation of cells in G0/G1 phase with a reduction in S-phase cells.
Zhao R, Zhang SZ, Yao GD, Lu DQ, Jiang H, Xu ZP · 2006
Sanchez S et al. · 2006
Apoptosis was not induced in isolated cells and reconstructed epidermis thickness and proliferation were unchanged. No change in heat shock protein expression was observed in isolated keratinocytes. A slight but significant increase in Hsp70 expression was observed in reconstructed epidermis after 3 and 5 weeks of culture. Fibroblasts showed a significant decrease in Hsc70 depending on culture conditions.
Lantow M, Lupke M, Frahm J, Mattsson MO, Kuster N, Simko M. · 2006
The study investigated whether 1,800 MHz RF-EMF can induce ROS release or Hsp70 expression changes in human blood cells using various exposure conditions. PMA treatment significantly increased ROS production in both monocytes and lymphocytes compared to sham or incubator controls. GSM-DTX exposure at 2 W/kg produced a significant difference in monocyte ROS compared to sham, but this was attributed to lower ROS values in the sham condition, while lymphocytes showed no ROS changes. Hsp70 expression in monocytes did not differ after GSM-DTX exposure at 2 W/kg for 1 hour compared to incubator or sham controls at any post-exposure time point.
Simkó M et al. · 2006
The study investigated Hsp70 expression and free radical release in human Mono Mac 6 cells exposed to ultrafine particles and radiofrequency electromagnetic fields. Ultrafine particle exposure increased free radical release by 40-45% above negative control, an effect stronger than heat treatment. Radiofrequency electromagnetic field exposure alone did not change free radical levels. Combined exposure to RF and ultrafine particles did not enhance the particle effect on free radicals. Heat treatment increased Hsp70 expression in a time-dependent manner, while ultrafine particles, RF fields, or their combination had no effect on Hsp70.
Nasta F et al. · 2006
Simko M et al. · 2006
German researchers exposed human immune cells (monocytes) to radiofrequency radiation at 2 W/kg SAR - similar to cell phone levels - while also testing exposure to ultrafine air pollution particles. They measured two key stress indicators: free radical production and heat shock proteins. While the air pollution particles triggered significant stress responses, the RF radiation produced no measurable effects on either stress marker, even when combined with the particles.
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.
Galloni P et al. · 2005
Researchers divided 48 Sprague-Dawley rats into exposed and sham-exposed groups. The rats were exposed 2 h/day, 5 days/week for 4 weeks at a local SAR of 2 W/kg in the ear. Distortion product otoacoustic emissions tests were carried out before, during, and after the exposure. The analysis showed no statistically significant differences in audiological signals between the different groups.
Cosquer B, Vasconcelos AP, Frohlich J, Cassel JC. · 2005
Ozguner F, Aydin G, Mollaoglu H, Gokalp O, Koyu A, Cesur G. · 2004
Researchers used thirty male Wistar-Albino rats divided into a nontreated control group, an irradiated group, and an irradiated group that also received melatonin. The irradiated group received 900 MHz radiation for 10 days at 30 minutes per day, and skin grafts were taken from the thoraco-abdominal area at the end of the tenth day. In the irradiated group, researchers observed increased thickness of stratum corneum, atrophy of epidermis, papillamatosis, basal cell proliferation, hypergranulosis, capillary proliferation, and impairment in collagen tissue distribution compared to the control group. Most of these changes, except hypergranulosis, were prevented with melatonin treatment.
Takahashi S et al. · 2002
Researchers investigated the mutagenic potential of 1.5 GHz electromagnetic near fields using brain tissues of Big Blue mice. Male BBM were locally exposed to EMF in the head region at 2.0, 0.67, and 0 W/kg specific absorption rate for 90 min/day, 5 days/week, for 4 weeks. There was no significant variation in the frequency of independent mutations of the lacI transgene in the brains. Deletion mutations were slightly increased in both the high and low EMF exposure groups as compared with the sham-exposed group, but the differences were not statistically significant.
Cranfield CG, Wood AW, Anderson V, Menezes KG. · 2001
Researchers tested whether simulated GSM mobile phone signals at 915 MHz and 2 W kg(-1) influence calcium concentration or calcium signalling patterns in a human lymphocyte cell line. No significant changes were found in the regression slope of calcium fluorescence, mean calcium concentration, number of calcium spikes, or mean height of those spikes. A significant alteration in average frequency from Fourier spectra was found in one category only: pulsed wave exposure of activated cells.
D'Andrea JA, Thomas A, Hatcher DJ · 1994
Researchers exposed four male rhesus monkeys to high-peak-power 5.62-GHz microwave pulses while the monkeys performed an operant task for food pellet rewards. Compared to sham exposures, significant alterations of lever responding, reaction time, and earned food pellets occurred at 4 and 6 W/kg but not at 2 W/kg. There were no differences between radar pulses and SLED pulses in producing behavioral effects.
Liddle CG, Putnam JP, Huey OP · 1994
Female CD1 mice were exposed from the thirty-fifth day of age for the remainder of their lives to 2.45 GHz CW microwave radiation at 3 or 10 mW/cm2. Exposures took place 1 h/day, 5 day/week in an anechoic chamber at an ambient temperature of 22 degrees C and a relative humidity of 50%. There were 25 animals in each exposure group, and an equal number of controls were concurrently sham exposed. The average life span of animals exposed at 10 mW/cm2 was significantly shorter than that of sham-exposed controls (572 days vs. 706 days; P = .049; truncation > 20%). In contrast, the average lifespan of the animals exposed at 3 mW/cm2 was slightly, but not significantly, longer (738 days) than that of controls (706 days).
Neubauer C, Phelan AM, Kues H, Lange DG · 1990
Researchers exposed male albino rats to 2.45-GHz microwaves with 10-microseconds pulses at 100 pps. Exposure at 10 mW/cm2 for 30 to 120 minutes increased tracer uptake through the blood-brain barrier. The uptake depended on both power density and exposure duration. At 5 mW/cm2, a 15-minute exposure had no effect. Pretreating rats with colchicine nearly completely blocked the microwave-induced uptake.
Dimbylow PJ, Mann SM. · 1994
Researchers built a mathematical model of the human head from MRI slices and used finite-difference time-domain (FDTD) calculations to estimate the specific energy absorption rate (SAR) at 900 MHz and 1.8 GHz. The generic transceiver was represented by a quarter-wavelength monopole on a metal box, and three placement geometries were examined: vertical in front of the eye, and vertical and horizontal at the side of the ear. For the most typical position at the side of the head, the maximum SAR averaged over 10 g of tissue was 2.1 and 3.0 W kg(-1) per W of radiated power at 900 MHz and 1.8 GHz. Placement in front of the eye gave values of 3.1 and 4.6 W kg(-1) per W averaged over 10 g of tissue at 900 MHz and 1.8 GHz.
Vijayalaxmi · 2006
Researchers exposed peripheral blood lymphocytes from healthy volunteers to 2.45 GHz or 8.2 GHz pulsed-wave RF radiation for 2 hours. They measured chromosomal aberrations and micronuclei to assess cytogenetic damage. The RF-exposed lymphocytes showed no significant increase in damage compared to sham-exposed lymphocytes. Gamma-irradiated positive control cells showed significantly more damage than both RF-exposed and sham-exposed cells.
Vijayalaxmi, Leal BZ, Szilagyi M, Prihoda TJ, Meltz ML, · 2000
Researchers exposed human blood cells to 2450 MHz radiofrequency radiation (the same frequency used in microwave ovens and some WiFi) for 2 hours to see if it would damage DNA. They found no evidence of DNA damage - the cells looked identical to unexposed cells, while cells exposed to ionizing radiation showed clear damage. This suggests that RF radiation at these levels doesn't break DNA strands in human immune cells.
Vijayalaxmi, Leal BZ, Szilagyi M, Prihoda TJ, Meltz ML · 2000
Human peripheral blood samples from three volunteers were exposed to pulsed-wave 2450 MHz radiofrequency radiation for 2 hours. The exposure used a net forward power of 21 W with an average power density of 5 mW/cm2 and a mean specific absorption rate of 2.135 W/kg. DNA damage was measured using the alkaline comet assay immediately and 4 hours after exposure. No significant differences were found in comet tail length, fluorescence intensity, or tail moment between RF-exposed and sham-exposed lymphocytes at either time point. The response of lymphocytes exposed to ionizing radiation was significantly different from RF-radiation- and sham-exposed cells.
