de Seze R, Ayoub J, Peray P, Miro L, Touitou Y · 1999
Researchers evaluated maximum serum melatonin concentration, time of maximum, and area under the curve of the hormone profile. Thirty-eight men aged 20 to 32 years were exposed to GSM 900 or DCS 1800 phones for 2 hr/day, 5 days/wk, for 4 wk at maximum power. Blood samples were collected hourly during the night and every 3 hr in the daytime across four sessions at 15-day intervals. The melatonin circadian profile was not disrupted by the exposure.
Adair ER, Cobb BL, Mylacraine KS, Kelleher SA, · 1999
Researchers measured thermoregulatory responses in two groups of seven adult volunteers exposed for 45 minutes to whole-body radio-frequency fields at either 450 or 2450 MHz. At each frequency, two power densities were tested at each of three ambient temperatures (24, 28, and 31 degrees C), along with no-RF control conditions. No change in metabolic heat production occurred under any exposure conditions at either frequency. At both frequencies, normalized peak SARs in excess of ANSI/IEEE C95.1 guidelines were easily counteracted by normal thermophysiological mechanisms.
Unknown authors · 1999
Researchers exposed groups of 100 female Sprague-Dawley rats to 50 Hz magnetic fields at 1 or 5 G, or 60 Hz at 1 G, for 18.5 hours a day, 7 days a week, for 13 weeks after initiating mammary tumors with DMBA. A second study used a lower DMBA dose of 2 mg and exposed rats to 50 Hz fields at 1 or 5 G for the same duration. Magnetic field exposure did not affect body weight, tumor latency, or tumor size in either study, and the authors concluded there was no evidence that 50 or 60 Hz fields promoted breast cancer.
Unknown authors · 1999
Groups of 100 female Sprague–Dawley rats were initiated with a single 10 mg gavage dose of DMBA at 50 days of age and then exposed to ambient fields, 50 Hz magnetic fields at 1 or 5 Gauss, or 60 Hz fields at 1 Gauss for 18.5 hours per day, 7 days per week for 26 weeks. There was no effect of magnetic field exposure on body weight gains or the time of appearance of mammary tumors. Carcinoma incidence was 96%, 90%, 95%, and 85% for the DMBA controls, 1 G 50 Hz, 5 G 50 Hz, and 1 G 60 Hz groups respectively, total carcinoma numbers were 649, 494, 547, and 433 with significant decreases in the 1 G 50 Hz and 1 G 60 Hz groups, and the authors concluded there was no evidence that 50 or 60 Hz magnetic fields promoted breast cancer under the conditions of this assay.
Unknown authors · 1999
Researchers conducted a double-blind laboratory study of 24 healthy young men to examine effects of intermittent versus continuous exposure to a 60 Hz, 28.3 microT magnetic field on EEG measures of night sleep. Intermittent exposure was associated with less total sleep time, reduced sleep efficiency, increased Stage II sleep, and decreased REM sleep, while continuous and sham exposure showed no such effects. Subjects exposed intermittently reported sleeping less well and feeling less rested in the morning compared to the other groups. All observed effects were significant at P < or = .04 or less.
Miyakoshi J, Koji Y, Wakasa T, Takebe H · 1999
Researchers exposed Chinese hamster ovary K1 cells to 5 mT ELFMF at 60 Hz for up to 6 weeks with or without X-irradiation. Long-term exposure to 5 mT ELFMF alone did not increase mutant frequency of the HPRT gene. However, exposure to 5 mT ELFMF after X-irradiation enhanced the X-ray-induced mutation rate. As little as 1 week of ELFMF exposure after X-irradiation increased the mutation rate.
Lu ST, Mathur SP, Akyel Y, Lee JC · 1999
Researchers exposed male Wistar-Kyoto rats to ultrawide-band electromagnetic pulses at 0.5-kHz and 1-kHz for 6 minutes. They measured cardiovascular functions including heart rate, systolic, mean, and diastolic pressures using a noninvasive tail-cuff sphygmomanometer. Exposure caused a significant decrease in arterial blood pressure that was robust, consistent, and persistent, while heart rate did not change. Cardiovascular functions were evaluated from 45 minutes to 4 weeks after exposure.
Unknown authors · 1999
Researchers investigated the effect of 50 Hz magnetic fields on the cytosolic calcium oscillator in Jurkat E6.1 cells at field strengths from 0 to 0.40 mT root mean square. The total spectral power of the cytosolic Ca2+ oscillator was reduced by magnetic field exposure and the effect increased in a dose-response manner. This reduction was also observed in the 0-10 mHz subinterval of the oscillation spectrum, while higher frequency subintervals showed no significant change.
Unknown authors · 1999
Researchers exposed human leukemia T-cells to 50 Hz magnetic fields (the same frequency as electrical power lines) and measured calcium oscillations inside the cells. They found that magnetic field exposure reduced these calcium signals in a dose-dependent manner - the stronger the field, the greater the reduction. This matters because calcium signaling is crucial for immune cell function and communication.
Linz et al. · 1999
Researchers tested the effects of radio frequency fields at 180, 900, and 1800 MHz on the electrical properties of isolated ventricular myocytes from guinea pigs and rats. The fields were applied using rectangular waveguides or a TEM cell at specific absorption rates up to 880 mW/kg, with 900 and 1800 MHz signals pulsed to the GSM standard. None of the tested electrophysiological parameters, including membrane potential, action potential, L-type calcium current, and potassium currents, were significantly changed by RF exposure. Lowering the temperature from 36°C to 24°C reduced current amplitude by almost 50% and shifted voltage dependence by about 5 mV, but RF exposure at the lower temperature still did not affect L-type calcium current.
Gandhi OP, Lazzi G, Tinniswood A, Yu QS, · 1999
Researchers compared numerical and experimental methods for determining SAR and radiation patterns of handheld wireless telephones at 835 and 1900 MHz. Peak 1-g SARs ranged from 0.13 to 5.41 W/kg, yet agreement between calculated and measured data was generally within plus or minus 20%. The study noted that for a maximum radiated power of 600 mW at 800/900 MHz, peak 1-g SARs can be higher than 1.6 W/kg unless antennas are carefully designed and placed further away from the head.
Unknown authors · 1999
Researchers exposed HBL-100 cells and normal human mammary epithelial cells to 60 Hz EMF at flux densities of 0.1, 1.0, and 10.0 Gauss for periods ranging from 20 min to 24 h. Gene expression was quantitated using ribonuclease protection assays. EMF exposure had no statistically significant effect on basal levels of c-myc transcripts in either human breast cell model, and had no effect on alterations in c-myc expression induced by 12-O-tetradecanoylphorbol-13-acetate. Transcript levels of c-erbB-2, p53, p21, GADD45, bax, bcl-x, mcl-1, and c-fos were also unaffected by EMF exposure.
Unknown authors · 1999
Researchers exposed human breast cells to 60 Hz magnetic fields (the same frequency as household electricity) at various strengths for up to 24 hours to see if EMF exposure would alter cancer-related genes. The study found no significant changes in gene expression for key cancer markers like c-myc, p53, and others, suggesting 60 Hz magnetic fields don't promote breast cancer through genetic mechanisms.
Unknown authors · 1999
Researchers exposed human breast cells to 60 Hz magnetic fields at various strengths (0.1 to 10 Gauss) for up to 24 hours to test whether power line frequencies could trigger cancer-related gene changes. The study found no significant effects on cancer-associated genes including c-myc, p53, and others, suggesting 60 Hz EMF is unlikely to promote breast cancer through direct gene expression changes.
Morrissey JJ et al. · 1999
Researchers investigated the effects of a one-hour exposure of mice to a 1.6-GHz radiofrequency signal, either continuous wave or pulse-modulated at 11 Hz (IRIDIUM), on c-fos gene expression in the brain. C-fos expression was not significantly elevated until exposure levels exceeded six times the peak dose and 30 times the whole-body average dose relative to human cellular telephone exposure limits. The pattern of c-fos elevation in limbic cortex and subcortex areas was consistent with a stress response due to thermal perception and restraint, not a direct interaction of IRIDIUM energy with brain tissue.
Trosic I, Matausicpisl M, Radalj Z, Prlic I, · 1999
The remaining 20 rats served as control. Exposed rats showed a decreasing tendency in total leukocyte and relative lymphocyte counts and a slight increase in granulocyte and erythrocyte counts.
Khadir R, Morgan JL, Murray JJ. · 1999
Researchers investigated the effects of a sinusoidal 60 Hz magnetic field on free radical production, degranulation, and viability in human neutrophils. Exposure of unstimulated human neutrophils to the magnetic field did not affect the functions examined. When cells were also stimulated with PMA, exposure to a 22 mT, 60 Hz magnetic field induced significant increases in superoxide anion production of 26.5% and in β-glucuronidase release of 53%. Release of lysozyme and lactate dehydrogenase was unchanged by the magnetic field, whether the cells were stimulated or not.
E.G Novoselova, E.E Fesenko, V.R Makar, V.B Sadovnikov · 1999
Researchers tested the effect of 8.15–18 GHz microwave radiation at a power density of 1 μW/cm2 on TNF production and immune response. A single 5-hour whole-body exposure induced a significant increase in TNF production in peritoneal macrophages and splenic T cells, and the mitogenic response in T lymphocytes also increased. The activation of cellular immunity was observed within 3 days after exposure. A diet containing β-carotene, α-tocopherol, and ubiquinone Q9 increased the activity of macrophages and T cells from irradiated mice.
Jauchem JR, Frei MR, Ryan KL, Merritt JH, Murphy MR · 1999
The study investigated the lack of effects on heart rate and blood pressure in ketamine-anesthetized rats briefly exposed to ultra-wideband electromagnetic pulses. Exposures at a repetition frequency of 1 kHz for 0.5 s or to repetitive pulse trains for a total of 2 min resulted in no significant changes in heart rate or mean arterial blood pressure. These results suggest that acute whole-body exposure to UWB pulses does not have a detrimental effect on the cardiovascular system.
Unknown authors · 1999
Researchers conducted a population-based case-control study across England, Wales, and Scotland. They measured household and school magnetic fields for 2226 matched case-control pairs and estimated average exposure in the year before diagnosis. For children with mean exposures above 0.2 microT compared to below 0-1 microT, the adjusted odds ratio for all malignant disease combined was 0.87 (95% CI 0.56-1.35).
Unknown authors · 1999
Unknown authors · 1999
Unknown authors · 1999
Researchers evaluated the effect of a 60 Hz electromagnetic field on NF-kappaB or AP-1-dependent reporter gene expression in human U937 leukemia cells. Reporter genes were electroporated into the cells and pathway activation was measured by CAT protein using CAT ELISA. Magnetic field intensities of 0.08, 0.1, 1.0, and 1.3 mT had no effect on either signaling pathway.
Unknown authors · 1999
Researchers studied DNA migration using the comet assay in brain cells of CBA mice exposed continuously to 50 Hz, 0.5 mT magnetic fields for 2 hours, 5 days, or 14 days. No differences were observed in mice exposed for 2 hours or 5 days compared with controls. Mice exposed for 14 days showed significantly extended DNA migration (0.02 < p < 0.05).
Unknown authors · 1998
The authors reviewed 23 studies published since their 1993 review of 55 studies plus six additional earlier studies. Three attempts to replicate previously reported positive results were unsuccessful. Negative studies in several exposure categories met the quality criteria.
