Miyakoshi J et al. · 2005
Researchers exposed human glioma MO54 cells to a continuous wave 1950 MHz RF field at SARs of 1, 2, and 10 W/kg for up to 2 hours. Cell growth was assessed by counting cell numbers up to 4 days after exposure. RF exposure at 2 and 10 W/kg did not affect the growth of MO54 cells. However, exposure at 10 W/kg for 1 and 2 hours significantly decreased the protein level of phosphorylated Hsp27 at serine 78.
Lim HB, Cook GG, Barker AT, Coulton LA. · 2005
Researchers exposed human peripheral blood to 900 MHz fields at specific absorption rates of 0.4, 2.0, and 3.6 W/kg for durations of 20 minutes, 1 hour, and 4 hours. Heat stress at 42 degrees Celsius increased the number of cells expressing HSP70 and HSP27 in a time-dependent manner. No statistically significant difference in stress protein expression was detected after RF-field exposure.
Lee JS, Huang TQ, Lee JJ, Pack JK, Jang JJ, Seo JS. · 2005
Researchers exposed eight-week-old hsp70.1-deficient mice twice daily for 45 minutes with a 15-minute interval, five days a week for ten weeks at a whole-body average specific absorption rate of 0.4 W/Kg for both 849 MHz and 1763 MHz fields. They examined major tissues histopathologically, assessed cell proliferative activity immunocytochemically, measured apoptosis with a TUNEL assay, and evaluated heat shock protein expression and stress-activated kinase phosphorylation by western blot. No histopathological differences were found between sham- and RF-exposed mice, and there was no evidence of increased proliferative or apoptotic activity. Levels of HSP90, HSP70, and HSP25 showed no obvious changes, and RF exposure did not affect phosphorylation of ERK1/2, JNK1/2, or p38 MAPK.
Huang TQ, Lee JS, Kim TH, Pack JK, Jang JJ, Seo JS. · 2005
The study used 80 male ICR mice initiated with DMBA and then exposed to 849 MHz or 1,763 MHz RF radiation at 0.4 W/kg SAR for 19 weeks. No skin tumors were observed in the sham or RF-exposed groups, while the TPA positive control group had a 95% tumor incidence. Pathological examination and PCNA staining showed no differences between sham and RF-exposed groups, and cyclin D1 and c-fos expression was only detected in TPA-induced tumors. The researchers concluded that RF radiation does not act as a tumor promoter for skin tumors in this model.
Green AC et al. · 2005
Intracellular calcium concentration ([Ca(2 +) ](i)) was measured in cultured rat cerebellar granule cells and cardiac myocytes during exposure to TETRA fields (380.8875 MHz pulse modulated at 17.6 Hz, 25% duty cycle). Granule cells exposed at specific absorption rates (SARs) of 5, 10, 20, 50 or 400 mW x kg(-1) showed no significant changes in resting [Ca(2 +) ](i). Exposure to TETRA (50 or 400 mW x kg(-1)) had no significant effect on either the rate or amplitude of spontaneous Ca(2 +) transients in cardiac myocytes. Overall, these results showed no evidence of any consistent or biologically relevant effect of TETRA fields on [Ca(2 + )](i) in granule cells and cardiac myocytes at any of the SAR tested.
Gorlitz BD et al. · 2005
Christ A, Kuster N. · 2005
The study investigates differences in RF energy absorption in the heads of adults and children. It discusses absorption mechanisms, tissue parameters, the effect of the pinna, and uncertainties in head models based on spheroids, scaled adult heads, and MRI data of children. The review concludes that energy exposure does not increase due to smaller heads, but identifies open issues regarding dielectric tissue parameters and pinna thickness.
Zeni O et al. · 2005
Researchers exposed human peripheral blood leukocytes from healthy volunteers to a 900 MHz GSM signal for 2 hours at SARs of 0.3 and 1 W/kg. DNA damage was assessed with the comet assay, chromosome aberrations and sister chromatid exchanges were measured in stimulated lymphocytes, and cell proliferation was evaluated via the mitotic index. No statistically significant differences were observed between exposed and sham-exposed samples for any of these endpoints, while positive controls showed the expected increases in DNA damage.
Lee S et al. · 2005
The study used the serial analysis of gene expression (SAGE) method to measure genome-wide gene expression changes in cultured human HL-60 cells exposed to pulsed 2.45 GHz RF fields. After a 2-hour exposure, 221 genes showed altered expression, increasing to 759 genes after 6 hours. Apoptosis-related genes were upregulated while cell cycle genes were downregulated, with no significant increase in heat shock genes.
Keshvari J, Lang S. · 2005
Researchers used the finite-difference time-domain (FDTD) computational method to calculate specific absorption rate (SAR) in anatomically correct adult and child head models exposed to a half-wave dipole at 900, 1800, and 2450 MHz. The ear and eye regions were studied because they represent realistic exposure scenarios for mobile wireless communication devices.
Bit-Babik et al. · 2005
The study used FDTD computations to calculate locally averaged SAR in anatomically correct adult and child head models with the IEEE standard averaging algorithm. Peak local average SAR over 1 g and 10 g of tissue and electromagnetic energy penetration depths were about the same across all head models under the same exposure conditions. Child head models were created by linear scaling of the adult model and by transforming adult models based on children's external head shapes, with tissue properties kept the same. Modeling and experimental measurements also used three spheres filled with tissue-equivalent mixture to approximate heads of increasing size.
Anghileri LJ, Mayayo E, Domingo JL, Thouvenot P. · 2005
Mice were treated with 1 hour per week of radiofrequency exposure for 4 months while a sham-exposed group served as controls. The evolution of carcinogenesis was followed up to 18 months, and the maximal life span of control mice was about 24 months. All dead animals were clinically and histologically examined to give an age-determined comparative quantification of the evolving carcinogenesis. A radiocalcium tracer method permitted the evaluation of radiofrequency effects on transmembrane transport of extracellular calcium at 1 and 24 hours after exposure, and the determination of induced lipid peroxidation completed this second study.
Vangelova KK, Israel MS. · 2005
Researchers measured urinary 6-sulphatoxymelatonin and three stress hormones in 36 male operators working fast-rotating extended shifts under radiofrequency electromagnetic radiation. Exposure levels were high for broadcasting station operators, low for TV station operators, and very low for satellite station operators. Radiofrequency EMR had no effect on the typical diurnal pattern of 6-sulphatoxymelatonin. High-level exposure significantly increased excretion rates of cortisol, adrenaline, and noradrenaline, while low-level exposure changes were not significant. The 24-hour excretion of cortisol and noradrenaline correlated with time-weighted average exposure measures.
Nikolova T et al. · 2005
ELF-EMF significantly affected transcript levels of bcl-2, bax, and GADD45 genes but did not affect neural-specific gene mRNA levels. RF-EMF down-regulated neural-specific Nurr1 and up-regulated bax and GADD45 mRNA levels. Short-term RF-EMF exposure for 6 hours caused a transient increase in DNA double-strand breaks, while 48-hour exposure did not. No effects were observed on mitochondrial function, nuclear apoptosis, cell proliferation, or chromosomal alterations.
Huber R et al. · 2005
Researchers investigated the effects of radio frequency electromagnetic fields similar to those emitted by mobile phones on waking regional cerebral blood flow in 12 healthy young men. Positron emission tomography scans were taken after 30 min unilateral head exposure to pulse-modulated 900 MHz RF EMF, and a sham control condition was also included. Only the 'handset-like' signal, which had stronger low-frequency components, increased relative cerebral blood flow in the dorsolateral prefrontal cortex on the side of exposure; the 'base-station-like' signal did not.
Finnie JW. · 2005
Researchers exposed mice to 900 MHz radiofrequency fields using a purpose-designed exposure system, giving each animal a single, far-field, whole body exposure at a specific absorption rate of 4 W/kg. The study measured activation of the immediate early gene c-fos in mouse brain tissue after this acute exposure. Activation of c-fos in exposed and sham-exposed brains was comparable, but was greatly increased compared with freely moving controls. The results suggest that the majority of the acute genomic response detected by c-fos expression was due to immobilisation.
Ebert S et al. · 2005
This study determined the thermal regulatory and thermal breakdown thresholds for in-tube restrained B6C3F1 and NMRI mice exposed to radiofrequency electromagnetic fields at 905 MHz. The thermal regulatory threshold of the restrained mice was found at SAR levels between 2 W kg(-1) and 5 W kg(-1). The breakdown of regulation was determined at 10.1 +/- 4.0 W kg(-1) for B6C3F1 mice and 7.7 +/- 1.6 W kg(-1) for NMRI mice. NMRI mice were more sensitive to thermal stress and responded at lower SAR values with regulation and breakdown.
Aitken RJ, Bennetts LE, Sawyer D, Wiklendt AM, King BV. · 2005
Researchers exposed mice to 900 MHz RFEMR at a specific absorption rate of approximately 90 mW/kg inside a waveguide for 7 days at 12 h per day. Sperm number, morphology, and vitality were not significantly affected by the exposure. However, detailed DNA analysis using QPCR revealed statistically significant damage to both the mitochondrial genome and the nuclear beta-globin locus.
Adair ER et al. · 2005
Researchers measured thermoregulatory responses in six adult volunteers during 45-minute whole-body exposures to 220 MHz radio frequency energy at three power densities and three ambient temperatures. Esophageal temperature showed small changes of no more than 0.35 °C and never exceeded 37.3 °C under any test condition. Vigorous sweating occurred at PD = 12 and 15 mW/cm(2), with sweating levels higher than those observed for equivalent PD at 100 MHz. The researchers concluded that exposed subjects thermoregulate efficiently through increased heat loss responses, particularly sweating.
Baohong Wang et al. · 2005
Researchers studied whether 1.8 GHz radiofrequency field radiation (RFR) at a SAR of 3 W/kg could interact with four chemical mutagens to damage DNA in human lymphocytes in vitro. DNA damage was detected using comet assay at two incubation times after treatment. RFR alone showed no difference in DNA damage compared to the control group, but co-exposure with MMC or 4NQO produced significantly greater DNA damage than those chemicals alone. Co-exposure with bleomycin or methyl methanesulfonate did not significantly increase DNA damage compared with those chemicals alone.
Diem E, Schwarz C, Adlkofer F, Jahn O, Rudiger H. · 2005
Researchers exposed cultured human diploid fibroblasts and transformed GFSH-R17 rat granulosa cells to 1800 MHz RF-EMF at SAR levels of 1.2 or 2 W/kg, using both intermittent and continuous exposures. DNA strand breaks were determined by means of the alkaline and neutral comet assay. Effects occurred after 16 h exposure in both cell types, and intermittent exposure showed a stronger effect in the comet assay than continuous exposure. The researchers concluded that the induced DNA damage cannot be based on thermal effects.
Balmori A. 2004 · 2004
A large majority of independent researchers recognize non-thermal effects of these waves on living beings, which are not yet contemplated in Spanish legislation. Power density levels billions of times lower would provide sufficient coverage for mobile telephony to function.
Anderson, L. · 2004
Researchers conducted a two-year chronic bioassay to determine whether long-term exposure to a 1.6 GHz radiofrequency field would affect cancer incidence in Fischer 344 rats. Timed-pregnant rats were assigned to far-field RF Iridium or sham groups, with whole-body exposures starting at 19 days gestation for 2 hours per day, 7 days per week until weaning. Offspring then received near-field head-first exposures 2 hours per day, 5 days per week from 36 days old until 2 years of age at brain SAR levels of 1.6 W/kg, 0.16 W/kg, or sham. No statistically significant differences were seen among groups for live pups per litter, survival index, weaning weights, clinical signs, or neoplastic lesions, and male survival was similar across groups while female cage controls had reduced survival time.
Hook, G. · 2004
The study measured intracellular oxidants, glutathione disulfide accumulation, antioxidant enzyme activities, nitric oxide production, and cell viability. FMCW- and CDMA-modulated RF radiation did not alter any measured oxidative stress parameters or cell toxicity.
Unknown authors · 2004
Case reports of peripheral neurological effects of radiofrequency radiation describe mainly disturbances of noxious sensation called dysaesthesia. Cases have arisen after exposure to much of the frequency range from low MHz to GHz. After very high intensity exposures nerves may be grossly injured; however, after lower intensity exposures which may result in dysaesthesia, ordinary nerve conduction studies demonstrate no abnormality although current perception threshold studies may. Only a small proportion of similarly exposed persons develop symptoms. Some observations are not consistent with the hypothesis that all health effects of radiofrequency radiation arise from thermal mechanisms.
