Zhang DY, Xu ZP, Chiang H, Lu DQ, Zeng QL. · 2006
Chinese researchers exposed hamster lung cells to cell phone radiation at 1800 MHz (the frequency used by GSM networks) for either 1 or 24 hours to see if it would damage DNA. They found that 24-hour exposure at high intensity (3.0 W/kg) significantly increased DNA damage markers compared to unexposed cells, while 1-hour exposure showed no effect. This suggests that prolonged exposure to cell phone-type radiation may harm cellular DNA.
Zhang DY, Xu ZP, Chiang H, Lu DQ, Zeng QL. · 2006
Researchers exposed hamster lung cells to 1800 MHz radiation from GSM cell phones for 1 or 24 hours. Twenty-four hour exposure significantly increased DNA damage in 37.9% of cells versus 28.0% in unexposed cells, showing duration matters for cellular harm.
Chauhan V et al. · 2006
Researchers exposed human lymphoblastoma TK6 cells to 1.9 GHz pulse-modulated RF fields at SARs of 1 and 10 W/kg. They assessed expression of proto-oncogenes FOS, JUN, and MYC using real-time RT-PCR. They also monitored transcript levels of the heat-shock proteins HSP27 and inducible HSP70. Transcript levels in RF-exposed cells showed no significant difference compared to sham-exposed cells. Positive heat-shock controls showed significant elevation of HSP27, HSP70, FOS, and JUN, and a decline in MYC mRNA.
Lopez-Martin E et al. · 2006
The study investigated effects of mobile-phone-type radiation on cerebral activity of seizure-prone animals. Rats pretreated with subconvulsive picrotoxin and exposed to 2 hours of GSM-modulated 900 MHz radiation suffered seizures and showed markedly increased c-Fos levels in neocortex, paleocortex, hippocampus and thalamus. Non-irradiated picrotoxin-treated rats did not suffer seizures and had significantly lower c-Fos counts. Radiation caused no such differences in rats not pretreated with picrotoxin.
Chauhan V et al. · 2006
Researchers exposed HL-60 and MM6 cells to intermittent 1.9 GHz pulse-modulated RF fields at SARs of 1 and 10 W/kg for 6 hours. No significant changes in gene expression were found between sham-exposed and RF-exposed groups in either cell line. Positive heat-shock controls showed significant increases in HSP27, HSP70, c-fos, and c-jun at both time points.
Heikkinen et al. · 2006
RF radiation did not significantly affect mortality or organ-specific tumor incidence. The only significant difference was an increase in vascular tumors of the mesenteric lymph nodes in the high-RF group, but this was attributed to an unusually low rate in the sham group. Non-neoplastic findings showed isolated significant differences in lacrimal glands, lungs, liver, and skin, considered unrelated to RF radiation. The authors concluded that the results do not support co-carcinogenic effects of low-level long-term RF radiation exposure in rats.
Yu D, Shen Y, Kuster N, Fu Y, Chiang H. · 2006
No significant differences in overall mammary tumor incidence, latency, multiplicity, or size were observed between microwave-exposed and sham-exposed groups. A tendency for reduced adenocarcinoma incidence at 0.44 W/kg and increased incidence at 4.0 W/kg did not reach statistical significance. Cage control rats had higher body weight, higher tumor incidence, and shorter tumor latency than sham- and microwave-exposed groups.
Hondou T et al et al. · 2006
Researchers conducted a numerical investigation using a realistic human body model and an actual elevator size to assess SAR from a mobile phone modeled as a dipole antenna at 16 mm from the head. They used finite-difference time-domain technique with a supercomputer at frequencies of 900, 1500, and 2000 MHz with 250 mW transmitting power. Results showed that peak 10-g SAR depends on passenger and antenna position, with substantial increases in whole-body average SAR and peak 10-g SAR in the elevator over free-space values. However, the maximum values met international RF safety guidelines, with whole-body average SAR at 4.4% and peak spatial-average SAR at 78% of the guideline.
Finnie JW, Cai Z, Blumbergs PC, Manavis J, Kuchel TR. · 2006
Researchers exposed pregnant mice to 900 MHz fields at 4 W/kg for 60 minutes daily from gestation day 1 to 19. Control mice were sham-exposed or freely mobile without restraint. Fetal brains were examined for c-fos expression in multiple regions using immunohistochemistry. No difference in c-fos immunoreactivity was found between exposed and control fetal brains.
Sukhotina I, Streckert JR, Bitz AK, Hansen VW, Lerchl A · 2006
Researchers exposed isolated pineal glands from Djungarian hamsters to 1800 MHz continuous wave or GSM-modulated signals at SAR levels of 8, 80, 800, and 2700 mW/kg for 7 hours. At 800 mW/kg SAR both signal types significantly enhanced melatonin release, but at 2700 mW/kg SAR continuous wave elevated melatonin while GSM-modulated exposure suppressed it. The authors concluded that the data do not support the melatonin hypothesis that nonthermal radiofrequency exposure suppresses melatonin synthesis.
Faraone et al. · 2006
Hoyto A, Sihvonen AP, Alhonen L, Juutilainen J, Naarala J · 2006
Researchers investigated the effects of low-level radiofrequency radiation and elevated temperature on ornithine decarboxylase (ODC) activity in murine L929 fibroblasts. RF radiation did not affect cellular ODC activity. A slight temperature increase of 0.8-0.9 degrees C in the exposure system led to decreased ODC activity, which was verified by exposing cells to different temperatures in incubators.
Masuda H et al. · 2006
Researchers exposed hairless female rats to GSM-900 or -1800 signals for 2 hours using a loop antenna on the back. The local specific absorption rate at skin level was about 5 W/kg. Skin thickness and cell toxicity did not differ between exposed and sham-exposed rats. Cell proliferation in the epidermis remained within normal range and no proliferation was seen in the dermis. Levels of filaggrin, collagen, and elastin were not significantly affected by the exposure.
Mora R, Crippa B, Mora F, Dellepiane M · 2006
The study measured transient evoked otoacoustic emission and auditory brainstem response in 20 healthy men before and after cell phone exposure. Exposure sessions lasted 15 to 30 minutes at 900 to 1,800 MHz. No significant changes in either measurement were observed throughout the study.
Sanchez S et al. · 2006
Researchers exposed five-week-old female hairless rats to GSM-900 or -1800 signals for 2 hours per day, 5 days a week, for 12 weeks. Skin thickness showed no significant difference between exposed and sham-exposed groups. Cellular proliferation measured by Ki-67 remained within normal range in exposed epidermis. Levels of filaggrin, collagen, and elastin did not differ significantly among groups.
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.
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.
Sun LX, Yao K, He JL, Lu DQ, Wang KJ, Li HW. · 2006
Researchers exposed human eye lens cells to cell phone radiation for 2 hours at different power levels. Lower levels caused repairable DNA damage, but higher power (4 W/kg) caused permanent breaks cells couldn't fix, suggesting a threshold where radiation overwhelms natural repair.
Sun LX, Yao K, He JL, Lu DQ, Wang KJ, Li HW. · 2006
Researchers exposed human eye lens cells to cell phone radiation for 2 hours at different power levels to see if it damages DNA. They found that lower exposure levels (up to 3 W/kg) caused temporary DNA breaks that the cells could repair, but higher exposure (4 W/kg) caused permanent DNA damage that cells couldn't fix.
Sun LX, Yao K, Jiang H, He JL, Lu DQ, Wang KJ, Li HW · 2006
Researchers exposed cultured human lens epithelial cells to 217 Hz modulated microwave radiation at four SAR levels for 2 hours. DNA single strand breaks were measured using the comet assay immediately after irradiation and at 30 and 60 minutes afterward. At the highest dose, significant DNA damage remained one hour after irradiation and cell proliferation was significantly decreased.
Sun LX, Yao K, He JL, Lu DQ, Wang KJ, Li HW · 2006
Chinese researchers exposed human eye lens cells to mobile phone radiation (1.8 GHz) at different power levels for 2 hours to see if it damaged DNA. They found that lower exposure levels (1-3 W/kg SAR) caused either no DNA damage or damage that the cells could repair within an hour, but the highest level (4 W/kg SAR) caused permanent DNA damage that cells couldn't fix.
Zhao R, Zhang SZ, Yao GD, Lu DQ, Jiang H, Xu ZP · 2006
Qutob SS et al. · 2006
Researchers exposed U87MG glioblastoma cells to a 1.9 GHz pulse-modulated RF field for 4 hours at SARs of 0.1, 1.0, and 10.0 W/kg to assess global gene expression. No evidence was found that non-thermal RF fields affect gene expression in these cells compared to nonirradiated controls. Heat shock at 43°C for 1 hour up-regulated typical stress-responsive genes in the positive control group.
Shen YH, Yu D, Fu YT, Chiang H. · 2006
Five hundred female Sprague Dawley rats received a single dose of 35 mg/kg DMBA and were divided into five groups with SARs of 0, 0.44, 1.33, and 4.00 W/kg, exposed for 4 hours per day, 5 days per week for 26 weeks. The sham-exposure group had a 37% carcinoma incidence, while the exposure groups at 0.44, 1.33, and 4.00 W/kg had incidences of 25%, 34%, and 38% respectively, with no statistically significant differences between groups. The authors concluded that the study did not provide evidence that 900 MHz GSM microwave exposure promotes DMBA-induced mammary tumor development in 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.
