Fritze K et al. · 1997
Researchers studied the effect of GSM microwave exposure on gene activity in the rat brain by measuring messenger RNAs of hsp70, c-fos, c-jun, and GFAP using in situ hybridization histochemistry. The study used specific absorption rates of 0.3 W/kg, 1.5 W/kg, and 7.5 W/kg. Immediately after exposure, slight hsp70 messenger RNA induction was found in the cerebellum and hippocampus at 7.5 W/kg, but not at lower intensities. At 24 hours and seven days after exposure, no lasting protein changes, altered glial marker expression, or increased cell proliferation were observed.
French PW, Donnellan M, McKenzie DR, · 1997
Researchers exposed a human astrocytoma cell line, U-87 MG, to 835 MHz electromagnetic radiation for 20 min, 3 times per day for 7 days, at power densities of either 40 ± 15 mW cm−2 or 8.1 ± 3 mW cm−2. At the lower power density, the rate of DNA synthesis decreased and the cells flattened and spread out compared to unexposed cultures. At 40 mW cm−2 there were no effects on cell proliferation, but changes in cell shape included increased spreading and the appearance of actin-containing blebs on the membrane.
Donnellan M, McKenzie DR, French PW · 1997
Researchers exposed a mast cell line, RBL-2H3, to 835 MHz radiation for 20 minutes, three times per day for 7 days at a power density of 8.1 +/- 3 mW/cm2. From day 4 onward, DNA synthesis and cell replication increased, cell morphology changed, and beta-hexosaminidase release was significantly enhanced compared to unexposed cultures. No effects were seen on cytoskeletal protein synthesis or beta-actin mRNA levels. Morphological changes persisted following subculture for at least 7 days in the absence of further exposure.
Cleary, SF, Cao, G, Liu, LM, Egle, PM, Shelton, KR · 1997
Researchers investigated stress protein induction in HeLa and CHO cells following a 2-hour exposure to radiofrequency or microwave radiation. Cells were exposed under isothermal conditions maintained at 37 ± 0.2 °C. Neither microwave nor RF radiation had a detectable effect on stress protein induction.
Bortkiewicz et al. · 1997
This study evaluated the circulatory system function of workers occupationally exposed to medium-frequency electromagnetic fields. The study included 71 workers at four AM broadcast stations operating at 0.738–1.503 MHz and 22 workers at radio link stations who had no history of regular electromagnetic-field exposure. ECG abnormalities were significantly more frequent in exposed workers than in non-exposed workers (75% versus 25%, p = 0.006), and a tendency for more rhythm disturbances was observed in AM broadcast station workers.
Blick DW et al. · 1997
Researchers measured the power levels at which human skin first detected warmth from microwave radiation at frequencies of 2.45, 7.5, 10, 35, and 94 GHz. Detection thresholds were measured on the skin in the middle of the back in 15 adult male human subjects at all microwave frequencies and with infrared radiation. Sensitivity increased monotonically with frequency, and the threshold at 94 GHz (4.5 ± 0.6 mW/cm2) was more than an order of magnitude less than at 2.45 GHz (63.1 ± 6.7 mW/cm2). The threshold at 94 GHz was comparable to the threshold for infrared radiation (5.34 ± 1.07 mW/cm2).
Lai, H, Singh, NP, · 1997
Researchers investigated the effects of microwave exposure on DNA strand breaks in rat brain cells. They found that treating rats with either melatonin or the spin-trap compound PBN immediately before and after radiofrequency electromagnetic radiation exposure blocked the DNA strand breaks. Because both substances are free radical scavengers, the researchers hypothesized that free radicals are involved in the radiofrequency electromagnetic radiation-induced DNA damage.
Lai H, Singh NP · 1997
Researchers investigated whether melatonin and the spin-trap compound N-tert-butyl-alpha-phenylnitrone (PBN) could block the effect of magnetic fields on brain cell DNA. Rats were injected with melatonin or PBN immediately before and after two hours of exposure to a 60-Hz magnetic field at an intensity of 0.5 mT. Both drug treatments blocked the magnetic field-induced DNA single- and double-strand breaks in brain cells, as measured by a microgel electrophoresis method.
Fiorani M et al. · 1997
Researchers investigated the effects of 50 Hz magnetic fields (0.2–0.5 mT) on rabbit red blood cells exposed at the same time to an oxygen radical-generating system, Fe(II)/ascorbate. A 0.5 mT magnetic field had no effect on intact red blood cells, but when cells were already under oxidative stress, exposure caused a significant further decay in hexokinase activity of about 20% and a twofold increase in methemoglobin production. The researchers concluded that the magnetic fields studied were able to potentiate the cellular damage induced in vitro by oxidizing agents.
Lai H, Carino MA, Singh NP · 1997
Researchers exposed rats to 2450 MHz pulsed radiofrequency radiation at a power density of 2 mW/cm2 for 2 hours and then measured DNA double strand breaks in brain cells. The RFR exposure significantly increased DNA double strand breaks in rat brain cells, and the effect was partially blocked by naltrexone treatment. The researchers concluded that endogenous opioids play a mediating role in RFR-induced DNA strand breaks in brain cells of the rat.
Balodis V, G Briimelis, K Kalviskis, et al. · 1996
Dr Cherry was invited by the New Zealand Ministry of Health and Ministry for the Environment to peer-review the proposal to adopt the ICNIRP guidelines for cell sites in November 1999. The review found that the ICNIRP assessment ignored all published studies showing chromosome damage and was highly selective, biased, and dismissive of genotoxic and epidemiological evidence. The assessment gave the impression of being predetermined to accept only effects from high exposures causing electric shocks or tissue heating, and it misrepresented two studies that actually showed significant increases in brain/CNS cancer.
Unknown authors · 1996
Researchers transfected HeLa cells with plasmids containing c-fos upstream regulating regions up to -700 base pairs linked to a CAT reporter gene. The cells were exposed to a 60 Hz electromagnetic field at 60 mGrms. CAT expression increased above control levels after 5 minutes of exposure, peaked at 20 minutes, and returned to basal levels after 40 minutes. Deletion analysis identified a responsive region of 138 base pairs from -363 to -225 containing SRE/AP-1 sites.
Unknown authors · 1996
Researchers exposed human melanoma MeWo cells to a 50-Hz, 400-mT extremely low frequency magnetic field and measured mutations in the hypoxanthine-guanine phosphoribosyl transferase gene. The mutant frequency increased with longer exposure periods and higher induced current intensities. Mutations induced by X-rays were enhanced by the magnetic field exposure. No significant increase in mutant frequency occurred when DNA replication was inhibited during exposure.
Unknown authors · 1996
The study examined the effects of extremely low frequency magnetic fields on cell growth and c-myc mRNA expression in Chinese hamster ovary cells. The study tested a 5 mT, 60 Hz magnetic field. The exposure system consisted of a CO2 incubator with built-in Helmholtz coils (250 mm inner diameter, 160 mm distance, 128 turns), a slide regulator, and a thermocontroller. No significant difference was found in growth rate or c-myc expression between cells exposed to the magnetic field, sham-exposed cells, and cells in a conventional incubator.
Unknown authors · 1996
Researchers treated cultured mammalian cells with three carcinogens that produce DNA single-strand breaks. The repair rate of these lesions was unchanged by 50 Hz electric, magnetic, or combined fields across a range of intensities.
Unknown authors · 1996
The researchers investigated whether 60-Hz magnetic fields act at the cellular level to produce gene expression changes that can result in neoplastic transformation. Twenty-four hour exposure to 200 microT continuous magnetic fields produced negative results in Syrian hamster embryo cells and C3H/10T1/2 murine fibroblasts, with or without a chemical promoter. Extensive coded and uncoded analyses found no magnetic field effect on gene expression in human HL60 cells. No MF-induced changes in ornithine decarboxylase expression were observed in C3H/10T1/2 cells under the same exposure conditions.
Unknown authors · 1996
The study investigated the combined effects of 954 MHz microwaves and the DNA damaging agent mitomycin C. Whole blood samples were exposed in vitro to a 954 MHz emitting antenna from a GSM base station. Lymphocytes were then cultivated in the presence of mitomycin C. A highly reproducible synergistic effect was observed in sister chromatid exchange frequencies in metaphase figures.
Unknown authors · 1996
Unknown authors · 1996
Researchers examined 21,744 male electrical utility workers in Québec and identified 49 suicide deaths between 1970 and 1988. Cumulative and current exposures to electric, magnetic, and pulsed electromagnetic fields were estimated using a job exposure matrix and both arithmetic and geometric means. The highest risk was seen in the medium exposure group for the geometric mean of electric fields, with a rate ratio of 2.76 (95% CI 1.15-6.62), while other fields showed mostly small non-significant increases.
Unknown authors · 1996
Researchers investigated interactions of weak ELFMFs with primitive haemopoietic cells in vitro using the multipotential progenitor cell line FDCP-mix(A4). They determined proliferative activity and clonogenic potential under optimal and sub-optimal growth conditions with exposures to ambient laboratory ELFMFs or three other ELFMF regimes including nulled fields, Ca2+-ion cyclotron resonance at 50 Hz, and vertical 50 Hz fields of 6 muT(RMS). Using exposures of 1, 4, 7 and 21 days, they found no significant alteration of growth rate, cell-cycle state or clonogenic efficiency.
Unknown authors · 1996
Rats were trained in ten daily sessions on a 12-arm radial maze to assess spatial memory. Exposure to a 60 Hz magnetic field at 0.75 mT for 45 minutes before each session significantly retarded learning.
Unknown authors · 1996
Exposure of breast cancer cells to 12 mG, 1 G, or 9 G 60-Hz electromagnetic fields failed to stimulate Cdk2 or cyclin B1-cdc2 activity or cyclin D1 synthesis. Simultaneous co-exposure to 60-Hz fields and chemical promoters did not enhance Cdk2 activation beyond the effect of the chemical promoter alone. Estrogen and xenoestrogens stimulated estrogen receptor binding to the estrogen receptor element, but EMF did not.
Unknown authors · 1996
The ferromagnetic transduction model proposes that biogenic magnetic particles in the brain coupled to mechanosensitive ion gates may mediate interactions with environmental magnetic fields. The authors show that pulsed fields, square waves, and DC fields could force open these membrane gates long enough to disrupt normal neurophysiological processes. The extended model may explain central nervous system effects in epileptic patients exposed to low frequency square wave and DC magnetic fields.
Weyandt, TB, Schrader, SM, Turner, TW, Simon, SD · 1996
Researchers compared semen quality and hormone levels among artillerymen (n=30), radar equipment operators (n=20), and a comparison group (n=31). Questionnaire data showed many initial controls had potential microwave exposure as radar operators, so a comparison group without lead or microwave exposure was selected. Radar equipment operators with potential microwave exposure had significantly lower sperm counts per milliliter (P=0.009) and per ejaculate (P=0.027) than the comparison group. Artillerymen who perceived fertility concerns also had lower sperm counts per ejaculate (P=0.067) and per milliliter (P=0.014) than the comparison group.
Sparks PB, Mond HG, Joyner KH, Wood MP · 1996
Researchers exposed 16 implanted Telectronics META pulse generators to simulated GSM transmissions and a 2-W digital mobile telephone. The devices were programmed to maximum sensitivity and tested in unipolar and bipolar settings and rate adaptive and nonrate adaptive modes. At maximum sensitivity, 11 of 16 devices showed no EMI, while brief ventricular triggering, pauses, and one episode of pacemaker-mediated tachycardia occurred in the remaining devices. When programmed to routine sensitivities, only one device displayed rare single beat ventricular triggering, and no changes in minute ventilation rate adaptive pacing were observed.
