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.
Li et al. · 1999
Researchers exposed human fibroblast cells to 837 MHz continuous microwaves for 2 hours at SAR levels of 0.9 or 9.0 W/kg. TP53 protein levels were measured by Western blot at 2, 8, 24, and 48 hours after exposure. No significant changes in TP53 protein expression were found in exposed cells compared to sham or untreated cells at any time point. No morphological alterations were observed in microwave-treated cells compared to sham-treated cells.
Fesenko EE et al. · 1999
Researchers investigated how weak electromagnetic waves in the centimeter range affected the cytotoxic activity of natural killer cells in mice. Irradiation at 8.15 to 18 GHz at 1 microwatt per square centimeter increased the cytotoxic activity of natural killer cells of rat spleen. In mice exposed for 24 to 72 hours, natural killer cell activity increased by 130 to 150%, and this elevated activity persisted for 24 hours after exposure ended. Microwave irradiation of animals in vivo for 3.5 and 5 hours, and a short exposure of splenic cells in vitro, did not affect natural killer cell activity.
Fesenko EE et al. · 1999
Russian researchers exposed mice to weak microwave radiation (8.15-18 GHz) for 24-72 hours and found their natural killer cells - immune cells that fight cancer and infections - became 130-150% more active. The immune boost lasted at least 24 hours after exposure ended, but shorter exposures of just a few hours showed no effect.
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.
Adey WR et al. · 1999
Researchers tested an 836.55 MHz NADC-modulated field in a 2-year bioassay with fetal exposure in Fischer 344 rats. Of 236 original rats, 182 (77%) survived to termination at age 709-712 days. There was no evidence of tumorigenic effects in the CNS from TDMA field exposure. Exposed animals showed trends toward reduced incidence of spontaneous CNS tumors (P < 0.16) and ENU-induced CNS tumors (P < 0.16). In preterm rats where neural tumors caused death, fields decreased ENU-induced tumor incidence (P < 0.03).
Schonborn F, Burkhardt M, Kuster N · 1998
In order to investigate the differences in absorption between adults and children due to their differing anatomies, simulations were performed using head phantoms based on MRI scans of an adult and two children aged 3 and 7 years. Ten different tissue types were distinguished and all simulations were performed using a commercial code based on the finite integration technique. The differences in absorption were investigated for the frequencies of 900 MHz and 1,800 MHz using 0.45 lambda dipoles instead of actual mobile phones. The results revealed no significant differences in the absorption of electromagnetic radiation in the near field of sources between adults and children.
Wagner, P, Roschke, J, Mann, K, Hiller, W, Frank, C · 1998
Researchers recorded all-night polysomnographies of 24 healthy male subjects with and without exposure to a circularly polarized 900 MHz pulsed electromagnetic field at 0.2 W/m². Suppression of REM sleep and a sleep-inducing effect under field exposure did not reach statistical significance, so previous results indicating alterations of these sleep parameters could not be replicated. Spectral power analysis also did not reveal any alterations of the EEG rhythms during EMF exposure.
Malyapa RS et al. · 1998
Researchers exposed rats to 2450 MHz microwave radiation (the same frequency used in microwave ovens and some WiFi devices) for 2 hours to see if it would damage DNA in brain cells, as a previous study had suggested. They found no DNA damage in either the brain's cortex or hippocampus regions, contradicting the earlier research. This study suggests that short-term exposure to this type of radiation at moderate levels may not cause immediate genetic damage to brain cells.
Imaida K et al. · 1998
Researchers exposed male F344 rats to a 929.2 MHz electromagnetic near-field for 90 minutes a day, five days a week, over six weeks. The exposed rats showed no significant difference in GST-P positive foci numbers or areas compared to sham-exposed rats. Maximum local specific absorption rates were 7.2 to 6.6 W/kg in the whole body and 2.0 to 1.7 W/kg in the liver.
Imaida et al. · 1998
Researchers exposed male F344 rats to a 1.439 GHz TDMA electromagnetic near-field for 90 minutes a day, 5 days a week, over 6 weeks. The rats were initiated with diethylnitrosamine and underwent partial hepatectomy at week 3. Peak liver SARs ranged from 1.91 to 0.937 W/kg and whole-body average SARs from 0.680 to 0.453 W/kg at 0.33 W antenna power. Exposure did not significantly alter the numbers or areas of GST-P-positive foci in the liver compared to sham-exposed rats. Serum levels of corticosterone, ACTH, and melatonin were increased in exposed rats.
Frei et al. · 1998
Researchers exposed 100 C3H/HeJ mice to continuous-wave 2450 MHz RF radiation at 1.0 W/kg for 78 weeks, 20 hours per day, 7 days per week, while 100 mice were sham-exposed. There was no significant difference in mammary tumor incidence between exposed mice (38%) and sham-exposed mice (30%). Latency to tumor onset was similar: 62.5 weeks for exposed mice and 62.0 weeks for sham-exposed mice. Histopathological evaluation found no significant difference in malignant, metastatic, or benign neoplasms between groups.
Walters TJ et al. · 1998
Researchers measured hypothalamic, cortical, tympanic, and rectal temperatures in rats exposed to 2.06 GHz microwave radiation at two power densities. The high-power density was 1700 mW/cm² with specific absorption rates of 1224 W/kg in hypothalamus and 493 W/kg in cortex, while the low-power density was 170 mW/cm² with SARs of 122.4 W/kg and 49.3 W/kg. During high-power exposure, the hypothalamic temperature rose significantly faster than cortical or rectal temperatures, whereas low-power exposure produced more uniform heating. For comparison, warm-water immersion produced uniform heating, while warm ambient exposure and exercise maintained the pre-existing temperature gradient between hypothalamus and cortex.
Dmoch A, Moszczynski P · 1998
Mickley GA, Cobb BL · 1998
Tolerant rats showed significantly lower hyperthermia on Day 2 and explored the novel object similarly to sham-exposed rats, whereas non-tolerant rats did not show a preference for the new object. Naltrexone (10 mg/kg) administered just before exposure blocked the hyperthermia-induced discrimination deficit in non-tolerant rats, making their exploration pattern resemble that of tolerant and sham-exposed animals.
Pavel A, Ungureanu CE, Bara II, Gassner P, Creanga DE · 1998
Researchers exposed wheat seeds with uniform genetic background to a microwave flow at 9.75 GHz and low intensity at various doses. Compared to controls, exposed seeds showed chromosomal aberrations including delayed chromosomes, micronuclei, interchromosomal bridges, and chromosomal fragments. The effects of microwaves at various doses on mitotic activity were also followed.
Novoselova ET, Fesenko EE. · 1998
Researchers studied whether weak electromagnetic waves in the centimeter range could affect tumor necrosis factor production in macrophages from mice. Whole-body microwave irradiation of male NMRI mice, exposure of macrophages in vitro, and irradiation of culture medium with 8.15-18 GHz at a power density of 1 microW/cm2 each caused a significant enhancement of tumor necrosis factor production in peritoneal macrophages.
Novoselova ET, Fesenko EE. · 1998
Russian researchers exposed mice to extremely weak microwave radiation (8.15-18 GHz) at power levels 1,000 times lower than cell phones. The exposure significantly increased production of tumor necrosis factor, a key immune protein, suggesting even very low-level microwaves can alter immune function.
Nakamura et al. · 1998
Researchers exposed pregnant rats to microwaves at 2 mW/cm2, 2450 MHz for 90 minutes and measured natural killer cell activity and beta-endorphin levels. Microwave exposure raised colonic temperature and increased beta-endorphin in blood and anterior pituitary but did not change corticosterone. Naloxone administered before exposure increased natural killer cell activity and beta-endorphin in blood and placenta of pregnant rats.
Phillips et al. · 1998
Researchers exposed Molt-4 T-lymphoblastoid cells in vitro to pulsed radiofrequency signals at cellular telephone frequencies of 813.5625 MHz (iDEN® signal) and 836.55 MHz (TDMA signal) to detect DNA damage. The alkaline comet assay was used to measure DNA single-strand breaks in exposed cell cultures compared to sham-exposed cultures. At an SAR of 24 μW g−1, exposure to the iDEN® signal for 2 h and 21 h significantly increased DNA damage, while at 2.4 μW g−1 the same signal significantly decreased DNA damage. The researchers concluded that the data indicate a need to study the effects of exposure to RF signals on direct DNA damage and on the rate at which DNA damage is repaired.
Phillips et al. · 1998
Researchers exposed immune system cells to radiofrequency radiation from cell phone signals at extremely low power levels for 2 to 21 hours. They found that very low exposures actually reduced DNA damage, while slightly higher exposures increased DNA breaks in the cellular genetic material. This suggests that even minimal RF radiation can alter DNA integrity in immune cells, though the effects varied depending on the specific exposure level.
Braune, S, Wrocklage, C, Raczek, J, Gailus, T, Lucking, CH · 1998
The study enrolled seven healthy men and three women volunteers aged 26 to 36 years in a single-blind placebo-controlled design. Participants were exposed to a GSM 900 MHz signal at 2 Watt with a 217 Hz frame repetition rate for 35 min per session. Blood pressure and heart rate were recorded continuously with a Finapres device, while capillary perfusion was measured with an infrared plethysmograph on the right hand.
Kwee S, Raskmark P · 1998
Researchers exposed transformed human epithelial amnion cells to 960 MHz microwave fields at three power levels and three exposure times using a TEM cell. Cell growth was reduced in exposed cells compared to control and sham-exposed cells. The proliferation response varied with SAR level and exposure duration, showing a linear correlation between power level and growth change. At lower power levels, a longer exposure time was needed to reach the maximum effect, and repeated exposures did not alter the outcome.
Malyapa RS et al. · 1998
Researchers exposed male Sprague-Dawley rats to 2450 MHz continuous-wave microwaves for two hours at 1.2 W/kg specific absorption rate. No significant differences in DNA damage were found between sham-exposed and irradiated rats in either the cerebral cortex or hippocampus, regardless of euthanasia method. Rats euthanized by CO2 asphyxia showed more intrinsic DNA damage and greater experiment-to-experiment variation than those euthanized by guillotine. The authors concluded that guillotine euthanasia is the most appropriate method for DNA damage studies. The study did not confirm previous reports of DNA damage from 2450 MHz microwave exposure.
