Belyaev IY et al. · 2006
Researchers exposed rats to 915 MHz GSM microwaves for 2 hours at a SAR of 0.4 mW/g and then examined brain cells for DNA damage and gene expression changes. In the cerebellum, 11 genes were upregulated in a range of 1.34 to 2.74 fold and one gene was downregulated 0.48-fold (P < .0025). The exposure did not induce detectable DNA double strand breaks or changes in chromatin conformation.
Zhang DY, Xu ZP, Chiang H, Lu DQ, Zeng QL. · 2006
Researchers studied the effects of GSM 1800 MHz radiofrequency electromagnetic fields on DNA damage in Chinese hamster lung cells. Cells were intermittently exposed to GSM 1800 MHz RF EMF at a SAR of 3.0 W/kg for either 1 hour or 24 hours, using a pattern of 5 minutes on and 10 minutes off. After 24 hours of exposure, the percentage of gammaH2AX foci positive cells was 37.9 +/- 8.6%, significantly higher than the sham-exposed group at 28.0 +/- 8.4%. The 1-hour exposure showed no significant difference from sham exposure.
Sun LX, Yao K, He JL, Lu DQ, Wang KJ, Li HW. · 2006
Cultured LECs were exposed to 217 Hz modulated 1.8 GHz microwave radiation at specific absorption rates of 0, 1, 2, 3, and 4 W/kg for 2 hours. DNA single strand breaks were detected with comet assay at 0, 30, 60, 120, and 240 minutes after irradiation. At 1 and 2 W/kg, the difference in DNA breaks between exposure and sham exposure groups was not significant at any detection time. At 3 and 4 W/kg, differences were significant immediately and 30 minutes after irradiation, with the difference disappearing after one hour in the 3 W/kg group but persisting in the 4 W/kg group.
Paulraj R, Behari J. · 2006
Researchers exposed 35-day-old male Wistar rats to microwave radiation at 2.45 GHz and 16.5 GHz for 35 days to study effects on developing rat brain. After exposure, the researchers measured DNA single strand breaks in brain tissue using micro gel electrophoresis (comet assay), with fifty cells from each slide and two slides per animal observed. The study found a statistically significant increase (p < 0.001) in DNA single strand breaks in the brain cells of exposed rats.
Lixia S et al. · 2006
Researchers exposed human lens epithelial cells (hLEC) to a 1.8 GHz GSM radiofrequency field at SARs of 1, 2, and 3 W/kg for 2 hours and then measured DNA damage, Hsp70 expression, and cell proliferation. DNA breaks at 1 and 2 W/kg were not significantly different from controls at any time point, while the 3 W/kg dose showed significantly increased DNA damage only at 0 and 30 minutes after exposure. Hsp70 protein expression was significantly increased at 2 and 3 W/kg, but Hsp70 mRNA expression did not change in any group, and cell proliferation was unaffected at all doses.
Wolf FI et al. · 2005
Researchers exposed HL-60 leukemia cells, Rat-1 fibroblasts, and WI-38 diploid fibroblasts to 0.5-1.0 mT 50-Hz ELF-EMF for 24-72 hours. The treatment caused a dose-dependent increase in proliferation rate, about 30% after 72 hours at 1.0 mT. DNA damage increased dose-dependently with peaks at 24 and 72 hours. Pretreatment with the antioxidant alpha-tocopherol prevented both the proliferation increase and DNA damage, implicating redox mechanisms.
Unknown authors · 2005
Researchers investigated whether acute magnetic-field exposure could elicit DNA damage in brain cells from adult rats, adult mice, and immature mice. Rodents were exposed to a 60 Hz magnetic field at 0, 0.1, 1, or 2 mT for 2 h and brain cells were analyzed at 0, 2, and 4 h after exposure using the alkaline comet assay. No significant increase in DNA damage was detected at any magnetic-field strength or time point.
Unknown authors · 2005
Researchers exposed human placental cotyledons to magnetic fields of 2 mT and 5 mT at 50 Hz for 3 hours in vitro. They measured the concentration of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in cellular DNA. The results suggest that placental tissues possess a capacity to protect DNA against oxidative alterations from magnetic field intensities that have caused DNA damage in rat brain cells and electrolyte imbalances in cotyledons.
Unknown authors · 2005
Researchers exposed mice to 50 Hz electromagnetic fields at 0.2 mT or 6.4 mT for 4 weeks. DNA strand breakage in testicular cells was measured using single-cell gel electrophoresis, and sperm chromatin structure was analyzed by flow cytometry. The percentage of testicular cells with DNA migration increased from 25.64% in controls to 37.83% and 39.38% after exposure to 0.2 mT and 6.4 mT, respectively. Comet tail length and the percentage of DNA in the tail also increased significantly in both exposure groups. The proportion of sperm with abnormal chromatin structure (COMPalphaT) increased in both exposed groups, while S.D.alphaT and XalphaT did not change significantly.
Unknown authors · 2005
Researchers analyzed the effect of a clinically useful pulsed electromagnetic field on MG-63 human osteoblast-like cells. The cells were grown in medium with 0.5% or 10% fetal calf serum. PEMF increased thymidine incorporation and decreased putrescine, while spermidine and spermine were not significantly affected. c-myc was activated after 1 hour and then downregulated, while c-fos mRNA increased after 0.5 hour and then decreased.
Unknown authors · 2005
Unknown authors · 2005
Researchers exposed cultured cells from different tissues to intermittent 50 Hz, 1 mT ELF-EMF for 1-24 hours. They used alkaline and neutral comet assays to assess ELF-EMF-induced DNA strand breaks. The study identified three responder cell types (human fibroblasts, human melanocytes, rat granulosa cells) and three non-responder cell types (human lymphocytes, human monocytes, human skeletal muscle cells).
Vijayalaxmi , Obe G · 2005
The studies used animals, cultured rodent and human cells, and freshly collected human blood lymphocytes to assess DNA strand breaks, chromosomal aberrations, micronuclei, and sister chromatid exchanges. Of the 63 studies, 29 (46%) found no increased genetic damage, 14 (22%) suggested an increase, and 20 (32%) were inconclusive.
Unknown authors · 2005
Researchers exposed cultured human fibroblasts to intermittent 50 Hz ELF-EMF (5 minutes on, 10 minutes off) at 1 mT for 2 to 24 hours. Micronuclei frequency increased in a time-dependent manner, becoming statistically significant after 10 hours and plateauing at roughly three times the basal level after about 15 hours. Chromosomal aberrations were also elevated, reaching up to 10-fold above baseline.
Komatsubara Y et al. · 2005
Researchers exposed murine m5S cells to 2.45 GHz high-frequency electromagnetic fields for 2 hours at SARs of 5, 10, 20, 50, and 100 W/kg continuous wave and at a mean SAR of 100 W/kg pulse wave with a maximum of 900 W/kg. The effects were compared with sham-exposed controls and with mitomycin C and X-ray treatments as positive controls. No significant differences in chromosomal aberrations were observed between HFEMF-exposed cells and sham controls, while positive controls increased chromatid-type and chromosome-type aberrations.
Gorlitz BD et al. · 2005
Chang SK et al. · 2005
Researchers examined the biological effects of an 835-MHz EMF on bacterial reverse mutation (Ames assay) and DNA stability (in vitro DNA degradation) using tester strains exposed to a continuous waveform at a specific absorption rate (SAR) of 4 W/kg for 48 h. In the presence of the EMF, some strains showed increased mutation rates with certain mutagens while others showed antimutagenic effects, but these effects were not significantly repeated in other relevant strains. Exposure to 835-MHz EMF did not change the rate of DNA degradation measured using plasmid pBluescript SK(+) as an indicator. The researchers concluded that 835-MHz EMF under the study conditions neither affected reverse mutation frequency nor accelerated DNA degradation in vitro.
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.
Gandhi G, Singh P. · 2005
The study aimed to detect cytogenetic damage in mobile phone users by analyzing short-term peripheral lymphocyte cultures for chromosomal aberrations and buccal mucosal cells for micronuclei. The results showed increased micronucleated buccal cells and cytological abnormalities in cultured lymphocytes, indicating a genotoxic response from mobile phone use.
Gandhi G, Anita · 2005
Researchers investigated DNA and chromosomal damage in peripheral blood lymphocytes of 24 mobile phone users exposed to microwave frequencies of 800-2000 MHz. DNA damage measured by comet assay showed a mean comet tail length of 26.76 ± 0.054 mm with 39.75% of cells damaged, which was highly significant compared to controls. The in vivo capillary blood micronucleus test also revealed a highly significant frequency of micronucleated cells at 0.25.
Regoli F et al. · 2005
Trosic I, Busljeta I. · 2005
Researchers exposed Wistar rats to 2.45 GHz continuous RF/MW radiation for 2 hours daily, 7 days a week, at 5–10 mW/cm², with subgroups receiving 4, 16, 30, and 60 total hours of exposure. The frequency of micronucleated bone marrow erythrocytes was significantly increased after 15 irradiation treatments. No statistically significant differences in micronucleus frequency were observed after 2, 8, or 30 irradiation treatments.
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.
Markovà E, Hillert L, Malmgren L, Persson BR, Belyaev IY. · 2005
Researchers investigated the effects of GSM microwaves at different carrier frequencies on human lymphocytes from healthy persons and from persons reporting hypersensitivity to electromagnetic fields. They measured changes in chromatin conformation and analyzed proteins 53BP1 and gamma-H2AX, which have been shown to colocalize in distinct foci with DNA double-strand breaks. GSM microwaves affected chromatin conformation and 53BP1/gamma-H2AX foci similar to heat shock, and on average the same response was observed in lymphocytes from hypersensitive and healthy subjects.
