EMF Research Studies

Effects of high- frequency electromagnetic fields on DNA strand breaks using comet assay method

Miyakoshi, J., Yoshida, M., Tarusawa, Y., et al. · 2002

Induction of DNA strand breaks by intermittent exposure to extremely-low-frequency electromagnetic fields in human diploid fibroblasts

Unknown authors · 2002

Human diploid fibroblasts were exposed to continuous or intermittent ELF-EMF at 50 Hz, sinusoidal, for 24 hours at 1000 microT. The alkaline and neutral comet assays were used to evaluate DNA single-strand and double-strand breaks. Intermittent fields reproducibly resulted in a significant increase of DNA strand break levels, mainly DSBs, compared to non-exposed controls. The highest DNA strand break levels occurred with 5 minutes field-on and 10 minutes field-off intermittence.

Comparison of dose dependences for bioeffects of continuous-wave and high-peak power microwave emissions using gel-suspended cell cultures.

Pakhomov AG, Gaj ek P, Allen L, Stuck BE, Murphy MR · 2002

Researchers compared bioeffects of continuous wave and extremely high power pulse microwaves at 9.3 GHz and 1.25 W average power using yeast cell density in agarose gel. Cell density was strongly affected by irradiation and correlated with local temperature rise, but no statistically significant difference between CW and EHPP was found across the SAR range. A trend (P<0.1) for a difference appeared at average SAR of 100 W/kg and higher, corresponding to peak SAR above 20 MW/kg for EHPP.

The effects of low level microwaves on the fluidity of photoreceptor cell membrane.

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.

Characterization of electromagnetic interference of medical devices in the hospital due to cell phones.

Morrissey JJ, Swicord M, Balzano Q · 2002

Researchers tested 33 medical devices from four large teaching hospitals using standard North American and European cell phone signals. Only 4 devices showed disruption of critical function at distances of 25 cm or greater. Other interference was observed but was not critically disruptive and mainly occurred when transmitters were at full power and within 5 cm of the device. No cell phone signal was exempt from producing electromagnetic interference effects, and effects were not entirely predictable across signal types or device models.

Changes in gap junctional intercellular communication in rabbits lens epithelial cells induced by low power density microwave radiation.

Ye J, Yao K, Zeng Q, Lu D. · 2002

Rabbits' eyes were exposed to 5 mW/cm(2) and 10 mW/cm(2) power densities of microwave radiation for 3 hours. The fluorescence-recovery-after-photobleaching (FRAP) method was used to determine gap junctional intercellular communication, and laser scanning confocal microscopy detected connexin 43 localization and function. Gap junctional intercellular communication was inhibited by microwave radiation, especially in the 10 mW/cm(2) irradiated samples. A decrease in connexin 43-positive staining was seen in 5 mW/cm(2) x 3 h treated LECs, and intracellular space accumulation and cytoplasmic internalization were clearly demonstrated in the 10 mW/cm(2) group.

Calcium protects differentiating neuroblastoma cells during 50 Hz electromagnetic radiation

Unknown authors · 2001

Researchers demonstrated that a 50- to 60-Hz magnetic field interacts with cell differentiation through two opposing mechanisms. The field antagonizes the shift in cell membrane surface charges during early differentiation and modulates hyperpolarizing K channels by increasing intracellular calcium. The simultaneous onset of both mechanisms prevents alterations in cell differentiation. The authors propose that cells are normally protected against electromagnetic insult.

The influence of 1.2 microT, 60 Hz magnetic fields on melatonin- and tamoxifen-induced inhibition of MCF-7 cell growth

Unknown authors · 2001

Researchers independently replicated a study testing whether a 1.2 microT, 60 Hz magnetic field alters the effects of melatonin and tamoxifen on MCF-7 human breast cancer cells. In the melatonin experiment, repeated three times, melatonin reduced cell numbers by 16.7% after seven days, but this reduction disappeared when cells were exposed to the magnetic field. In the tamoxifen experiment, repeated nine times, tamoxifen reduced cell growth by 18.6% and 25% on days six and seven without the field, but only by 8.7% and 13.1% with the field. The results were consistent with the original findings of Harland and Liburdy.

Effects of low frequency pulsed electric field on insulin studied by fluorescent spectrum

Unknown authors · 2001

Effects of low frequency pulsed electric field on insulin studied by fluorescent spectrum. The experiment results demonstrate that the conformation of insulin molecular has been altered by electric fields exposure for 30 minutes or by heat exposure for 50 hours. The results suggest that pulsed electric field exposure as heat exposure will after conformation of insulin molecular by breaking some hydrogen bonds and recombining another hydrogen bonds.

Magnetic fields (MF) of 50 Hz at 1.2 microT as well as 100 microT cause uncoupling of inhibitory pathways of adenylyl cyclase mediated by melatonin 1a receptor in MF-sensitive MCF-7 cells

Unknown authors · 2001

Micronucleus induction in Syrian hamster embryo cells following exposure to 50 Hz magnetic fields, benzo(a)pyrene, and TPA in vitro

Unknown authors · 2001

Effect of immobilization and concurrent exposure to a pulse-modulated microwave field on core body temperature, plasma ACTH and corticosteroid, and brain ornithine decarboxylase, Fos and Jun mRNA.

Stagg RB et al. · 2001

Researchers exposed tube-restrained Fischer 344 rats to pulse-modulated 1.6 GHz Iridium cell phone fields at brain SARs of 0.16, 1.6 and 5 W/ kg for 2 hours. Core body temperature increased transiently by about 0.3 degrees C during the first 30 minutes of loose-tube restraint in conditioned animals. Immobilization alone caused a nearly 10-fold rise in ACTH and corticosterone in conditioned rats, and non-conditioned rats showed 3-10-fold higher hormone levels at 120 minutes. RF exposure did not change core body temperature, corticosterone, ACTH, or brain Odc, Fos, Jun mRNA compared with sham-exposed immobilized animals. The authors concluded that the pulse-modulated digital Iridium RF field at SARs up to 5 W/kg is incapable of altering these stress-related responses.

Neoplastic Transformation in C3H 10T(1/2) Cells after Exposure to 835.62 MHz FDMA and 847.74 MHz CDMA Radiations.

Roti Roti JL et al. · 2001

Researchers measured the effect of 835.62 MHz FDMA and 847.74 MHz CDMA radiation on neoplastic transformation frequency using the in vitro C3H 10T(1/2) cell transformation assay system. Cells were exposed at 37°C to either radiation at a specific absorption rate of 0.6 W/kg for 7 days to test for genotoxic effects, or after 4.5 Gy X-ray exposure for 42 days to test for epigenetic promotion effects. After both the 7-day and 42-day exposures, no statistically significant differences in transformation frequencies were found between incubator controls, sham-exposed groups, and RF-exposed groups.

Analysis of the influence of the cell geometry, orientation and cell proximity effects on the electric field distribution from direct RF exposure.

Sebastian JL, Munoz S, Sancho M, Miranda JM · 2001

Researchers calculated electric field intensity using the finite element method in single- and multilayer spherical, cylindrical, and ellipsoidal mammalian cell models exposed to 900 and 2450 MHz plane waves. They analyzed how cell geometry and orientation relative to the external field influence the electric field induced in the membrane and cytoplasm. The study found that cytoplasmic and extracellular bound water layers play a significant role in determining electric field intensity for cylindrical and ellipsoidal models.

[In vitro and in vivo study of electromagnetic compatibility of cellular phones and pacemakers]

Geller L, Thuroczy G, Merkely B. · 2001

Researchers examined electromagnetic compatibility of cellular phones and pacemakers in four phone systems and fifteen pacemaker types, both in vitro and in vivo in humans. They performed more than 1100 in-vitro and 130 in-vivo tests. No electromagnetic compatibility disturbance was observed with GSM and DCS 1800 MHz phones, while the highest problem rate occurred with NMT 450 MHz phones at 10.5% to 63%.

Low power density microwave radiation induced early changes in rabbit lens epithelial cells.

Ye J, Yao K, Lu D, Wu R, Jiang H. · 2001

Researchers exposed one eye of each rabbit to 5 mW/cm2 or 10 mW/cm2 microwave radiation for 3 hours, using the contralateral eye as a control. They used Annexin V-propidium iodide two-color flow cytometry to detect early changes in lens epithelial cells. At 5 mW/cm2, many lens epithelial cells were in the initial phase of apoptosis. At 10 mW/cm2, a large number of cells became secondary necrotic cells and severe damage was observed.

[Effect of vitamin E on morphological variation of retinal ganglion cells after microwave radiation].

Yang R, Chen J, Deng Z, Liu X, · 2001

Researchers cultured pig retinal ganglion cells in vitro, added vitamin E at different concentrations, and exposed them to 2450 MHz microwave radiation at 30 mW/cm² for 1 hour. Microwave exposure caused cell congregation, axon disappearance, mitochondria and endoplasmic reticulum swelling, and apoptosis. Vitamin E groups showed no obvious changes under optical microscope, though electron microscopy revealed light mitochondria swelling with intact cristae. The researchers concluded that microwave induced morphological damage and vitamin E reduced this damage to some extent.

Effect of low intensity pulse-modulated electromagnetic radiation on activity of alkaline phosphatase in blood serum

Pashovkina MS, Akoev IG · 2001

Researchers exposed samples to pulse-modulated electromagnetic radiation at 2375 MHz with intensities of 0.8, 8.0, and 40.0 microW/cm2, modulation range 30-310 Hz, for 1-3 minutes. They observed a change in alkaline phosphotase activity in vitro.

Evidence of Oxidative Stress in American Kestrels Exposed to Electromagnetic Fields

Fernie KJ, Bird DM. · 2001

Researchers investigated whether exposure to magnetic and electric fields similar to those from power lines induces an immune response and alters oxidative stress levels in American kestrels. Captive male kestrels were bred under control or EMF conditions equivalent to those experienced by wild kestrels. Short-term EMF exposure suppressed plasma total proteins, hematocrits, and carotenoids in the first half of the breeding season, and also suppressed erythrocyte cells and lymphocyte proportions while elevating granulosa proportions at the end of the breeding season. Long-term EMF exposure may be linked to higher levels of oxidative stress through EMF exposure only, and also suppressed hematocrits in the first half of the reproductive period.

Multinucleated giant cell appearance after whole body microwave irradiation of rats.

Trosic I · 2001

Researchers exposed rats to 2450 MHz microwaves at power densities of 5 to 15 mW/cm², in sessions of two hours each, with groups receiving 2, 8, 13, or 22 treatments. Multinucleated cells significantly increased (p<0.01) in treated animals, with the elevation being time- and dose-dependent. Cell viability did not significantly change in the irradiated animal group compared with the control group.

DNA damage in rat lymphocytes treated in vitro with iron cations and exposed to 7 mT magnetic fields (static or 50 Hz)

Unknown authors · 2000

Researchers incubated isolated rat lymphocytes for three hours in 7 mT static or 50 Hz magnetic fields, with some samples receiving iron chloride or hydrogen peroxide. Magnetic field exposure alone did not increase DNA damage in the comet assay. Iron chloride alone also did not produce detectable DNA damage. However, combined exposure to iron chloride and magnetic fields significantly increased damaged cells to about 20 percent for static fields and 15 percent for 50 Hz fields. Control samples showed about 97 percent of cells without DNA damage.

Increased chromatid-type chromosomal aberrations in mouse m5S cells exposed to power-line frequency magnetic fields

Unknown authors · 2000

Researchers exposed mouse m5S cells to power-line frequency magnetic fields at flux densities of 5, 50, and 400 mT for 40 hours. Cells were either untreated or pretreated with mitomycin C or X-rays before exposure. Exposure to 400 mT fields significantly increased chromosomal aberration frequency compared to unexposed controls. The induced aberrations were predominantly chromatid-type, with a three-fold increase at 400 mT. ELFMF exposure also deepened S or G2 arrest after DNA damage.

Exposure of Daudi cells to low-frequency magnetic fields does not elevate MYC steady-state mRNA levels

Unknown authors · 2000

Daudi cells were exposed to 60 Hz magnetic fields for 20, 40 or 60 min at flux densities of 12.5, 50, 100 or 500 microT. Exposures included sham/sham, exposed/sham or sham/exposed conditions with blinding, and 12-O-Tetradecanoylphorbol-13-acetate (TPA) treatment was used as a positive control. Human MYC expression was measured by northern blot hybridization as an indicator of the responsiveness of Daudi cells to experimental conditions, and beta-2-microglobulin (B2M) expression was measured simultaneously as an internal control. Exposure to 60 Hz magnetic fields did not significantly alter MYC expression in Daudi cells under any exposure condition.

Radiat Res 153(4):479-486, 2000

Unknown authors · 2000

50-Hertz magnetic field and calcium transients in Jurkat cells: results of a research and public information dissemination (RAPID) program study

Unknown authors · 2000

Researchers attempted to replicate earlier findings by testing whether a 1.5-G 50-Hz magnetic field alters intracellular free calcium in Jurkat lymphocyte T-cells. Cells were randomly assigned to magnetic field, sham field, or no-field exposures for 8 minutes each in a blinded design. The percentage of cells showing calcium transients was 16.5% for magnetic field, 14.6% for sham, and 14.2% for no field, with no statistically significant differences among them. The authors concluded that their methods did not identify responsive cells, if such cells exist, and that the results do not rule out a magnetic field effect on calcium.