McNamee JP et al. · 2002
Researchers exposed human white blood cells to cell phone radiation (1.9 GHz) for 2 hours at various power levels to see if it would damage DNA or cause genetic abnormalities. They found no evidence of DNA damage or genetic changes at any exposure level tested, including levels 5 times higher than typical cell phone use. This Canadian government study suggests that short-term radiofrequency exposure may not directly harm genetic material in immune cells.
Unknown authors · 2002
Zhang MB, He JL, Jin LF, Lu DQ. · 2002
Researchers studied whether 2450-MHz microwave radiation interacts with the chemical mitomycin C (MMC) to produce genotoxic effects in human lymphocytes in vitro. Blood cells from a male donor and a female donor were exposed to 2450-MHz microwaves at 5.0 mW/cm2 for 2 h, to MMC alone for 24 h, or to MMC for 24 h following microwave exposure. Microwave exposure alone did not significantly increase comet lengths compared with controls, but combined microwave plus MMC exposure produced significantly longer comet lengths than MMC alone at doses of 0.025 microgram/mL or higher.
Unknown authors · 2002
Researchers exposed Ku80-deficient xrs5 cells and Ku80-proficient CHO-K1 cells to ELF electromagnetic fields. ELF field exposure alone did not affect cell survival, cell cycle distribution, or protein expression in either cell line. In xrs5 cells, ELF exposure after irradiation inhibited G1 cell cycle arrest, increased bcl-2 expression, and decreased p53, phospho-p53, caspase-3, and p21 protein levels. ELF exposure for 10 hours after irradiation reduced X-ray-induced apoptosis in xrs5 cells from about 1.7% to 0.7%, but this effect was not observed in CHO-K1 cells.
Paulraj R, Behari J · 2002
Researchers exposed 35-day-old Wistar rats to low-level continuous 2.45 GHz microwaves for 2 hr/day over 35 days at a power density of 0.34 mW/cm2 with a specific absorption rate of 0.1 W/kg. Exposed rats showed a significant increase in calcium ion efflux and ornithine decarboxylase activity and a significant decrease in calcium-dependent protein kinase activity in brain tissue. The authors suggested that the radiation affects membrane-bound enzymes linked to cell proliferation and differentiation, indicating a possible tumor-promoting role.
Testylier G, Tonduli L, Malabiau R, Debouzy JC · 2002
Rats were exposed to 2.45 GHz continuous wave at 2 or 4 mW/cm(2) for 1 h during the day, or to 800 MHz modulated at 32 Hz at 200 mW/cm(2) for 1 or 14 h during the night. Exposure at 4 mW/cm(2) caused a significant 40% decrease in mean acetylcholine release from hippocampus, maximal at 5 h post exposure. Fourteen-hour nighttime exposure at 800 MHz induced a significant 43% decrease in acetylcholine release during 11 p.m.-4 a.m. compared to control rats.
Unknown authors · 2002
Researchers exposed 10-day-old mice to a 1 mT, 60 Hz magnetic field for 2 hours and measured DNA damage at multiple time points using the alkaline comet assay. They also measured apoptosis in the external granule cell layer of the cerebellum at 0 and 24 hours using the TUNEL assay. Increased DNA damage was detected by tail ratio at 2 hours but not by the other comet assay parameters, and no increase in apoptosis was observed compared to sham-exposed mice.
Mueller CH, Krueger H, Schierz C · 2002
This double-blind laboratory experiment tested whether people can perceive a 50 Hz electric and magnetic field at 100 V/m and 6 μT, and whether self-reported electromagnetic hypersensitivity (EHS) is related to that ability. A total of 63 volunteers, 49 with self-reported EHS and 14 controls, each judged 10 sham and 10 exposed two-minute blocks in randomized order. Seven of the 63 subjects reached a statistically significant result, but there was no relevant difference between self-reported EHS subjects and controls in perception success rate or in the number and types of symptoms reported.
Unknown authors · 2002
Researchers exposed differentiating IMR-32 neuroblastoma cells to 60 Hz magnetic fields at 50, 100, and 200 microT for 4 hours. They measured APP695 mRNA levels using northern hybridization with Digoxygenin-labeled probes. The results provided no support for any relationship between APP695 gene transcription and either differentiation age or magnetic field exposure.
Hanada E, Hoshino Y, Oyama H, Watanabe Y, Nose Y. · 2002
Researchers tested the effect of wireless LAN communication on medical electronic equipment and the effect of electronic equipment on wireless LAN communication. They observed nine pieces of electronic equipment in operating mode while transmitting radio waves from a wireless LAN. No equipment malfunction occurred even with the access point very close to the equipment surface during data transmission. Medical equipment caused little change in wireless communication effectiveness, but electric knives and a remote patient monitor reduced the reception rate to about 60%. Wireless LAN speed was temporarily reduced only when a microwave oven was close to and facing the access point.
Pologea-Moraru R, Kovacs E, Iliescu KR, Calota V, Sajin G · 2002
Researchers studied the effects of low-power microwaves at 2.45 GHz on the membrane fluidity of rod photoreceptor cells. The researchers expected the retina to be very sensitive to microwave irradiation due to the polar character of photoreceptor cells and high water content.
Miyakoshi, J., Yoshida, M., Tarusawa, Y., et al. · 2002
Unknown authors · 2002
Researchers analyzed expression of immediate early response genes c-fos, c-jun, and c-myc in human glioblastoma T98G cells exposed to 1-500 μT 60 Hz elliptically polarized magnetic fields for up to 3 h. No statistically significant differences were found in gene expression ratios at both transcriptional and translational levels for c-fos and c-jun at 30 min and for c-myc at 180 min after serum stimulation. Similarly, exposure to linearly or circularly polarized 500 μTr fields produced no significant change in expression ratios at both transcriptional and post-transcriptional levels.
Unknown authors · 2002
The paper compares maximum allowable powers for cellular telephones at 835 and 1900 MHz under ANSI/IEEE, ICNIRP, and a proposed IEEE modification. It shows the ANSI/IEEE guideline is the most conservative, ICNIRP allows 2.5-3 times higher maximum radiated power, and the proposed modification allows up to 50% higher power. Peak 1 g SAR in smaller head models is up to 56% higher at 1900 MHz and up to 20% higher at 835 MHz than in larger models. Plastic ear models yield SARs up to two or more times smaller than realistic anatomic models, and a 2 mm thin shell phantom with lossy ear is proposed to match anatomic SARs within +/- 15%.
Unknown authors · 2002
However, research reports indicate that living cells may respond to power-frequency fields well below the thermal noise limits. The study proposes that published thermal arguments may not fully account for all membrane force fields of thermal origin, and that a full accounting could show smaller net thermal noise fields in the power-frequency range.
Unknown authors · 2002
This 2002 theoretical study challenged the widely accepted belief that thermal noise in cell membranes would prevent power frequency electric and magnetic fields from affecting human cells. The researchers argued that previous thermal noise calculations were incomplete and that when all thermal forces are properly accounted for, the actual noise may be lower than thought, potentially allowing environmental EMF to influence cellular membranes.
Liu Y, Weng E, Zhang Y, Hong R. · 2002
Researchers exposed mice to a 50 Hz sinusoidal electromagnetic field at 0.2 mT or 6.0 mT for 2 weeks, and measured markers of the antioxidant system and cell membrane fluidity in brain and liver tissue. Malondialdehyde content in brain and liver increased with exposure, while total antioxidant capability decreased at both field strengths. When electromagnetic field exposure was combined with lead, the researchers observed synergic effects on lipid peroxidation.
Liu X, Shen H, Shi Y, Chen J, Chen Y, Ji A. · 2002
Trosic I, Busljeta I, Kasuba V, Rozgaj R. · 2002
Researchers exposed adult male Wistar rats to continuous 2450 MHz radiofrequency microwave radiation for 2 hours a day, 7 days a week, for up to 30 days, at a power density of 5–10 mW/cm2. Peripheral blood smears were examined for micronuclei in polychromatic erythrocytes as an indicator of genotoxicity. Micronuclei per 1000 PCEs were significantly increased after eight irradiation treatments compared with sham-exposed controls. The researchers noted that an adaptive mechanism in both erythrocytopoiesis and genotoxicity likely appeared during the subchronic irradiation treatment.
McNamee JP et al. · 2002
Human blood cultures were exposed to a 1.9 GHz continuous-wave radiofrequency field for 2 hours at SARs of 0.0, 0.1, 0.26, 0.92, 2.4, and 10 W/kg while temperature was maintained at 37.0 ± 0.5°C. DNA damage was measured immediately after exposure using the alkaline comet assay with four parameters, and micronucleus formation was assessed using the cytokinesis-block micronucleus assay. No evidence of increased primary DNA damage was detected at any SAR tested. There was no significant difference in micronucleus incidence between exposed cultures and sham controls at any SAR.
McNamee JP et al. · 2002
Blood cultures from human volunteers were exposed to an acute 1.9 GHz pulse-modulated radiofrequency (RF) field for 2 h using a series of six circularly polarized, cylindrical waveguides. Mean specific absorption rates (SARs) ranged from 0 to 10 W/kg and the temperature within the cultures during the exposure was maintained at 37.0 ± 0.5°C. DNA damage was quantified in leukocytes by the alkaline comet assay and the cytokinesis-block micronucleus assay. No evidence of increased primary DNA damage was detected by the comet assay and no significant differences in micronucleus frequency were found at any SAR tested.
McNamee JP et al. · 2002
Canadian researchers exposed human white blood cells to 1.9 GHz radiofrequency radiation (similar to cell phone frequencies) for 2 hours at various power levels up to 10 W/kg. They found no DNA damage in the cells compared to unexposed controls, using two different laboratory tests to detect genetic harm. This study suggests that short-term RF exposure at these levels does not cause immediate DNA breaks in immune cells.
Unknown authors · 2002
Female Sprague Dawley rats were MF or sham exposed for 2 weeks at a flux density of 100 microTesla. Proliferation of epithelial cells in the mammary tissue and adjacent skin was examined by in vivo labeling with bromodeoxyuridine (BrdUrd) and in situ labeling of Ki-67 protein by the antibody MIB-5. MF exposure significantly enhanced BrdUrd and Ki-67 labeling in the mammary epithelium, indicating a marked increase in cell proliferation. Melatonin levels in pineal or mammary glands were not affected by MF exposure. Topical application of 12-O-tetradecanoylphorbol-13-acetate increased BrdUrd and Ki-67 labeling in skin epithelial cells, particularly hair follicles, but not in mammary tissue.
Unknown authors · 2002
German researchers exposed female rats to 50 Hz magnetic fields at 100 microTesla (similar to power lines) for two weeks and found significantly increased cell division in mammary gland tissue. The study challenges the popular "melatonin hypothesis" by showing breast tissue effects occurred without changes in melatonin levels. This provides direct evidence that magnetic field exposure can stimulate breast cell proliferation, potentially explaining increased cancer risk.
Peyman A, Rezazadeh AA, Gabriel C · 2001
Researchers measured dielectric properties of ten rat tissues at six ages from 130 MHz to 10 GHz. Results showed a general decrease in dielectric properties with age. The decrease was more apparent in brain, skull, and skin tissues than in abdominal tissues. The variation was attributed to changes in water content and organic composition.
