EMF Research Studies

Effects of acute exposure to ultrahigh radiofrequency radiation on three antenna engineers.

Schilling, CJ · 1997

Blood-brain barrier permeability in rats exposed to electromagnetic fields used in wireless communication.

Persson BRR, Salford LG, Brun A · 1997

Researchers studied blood-brain barrier permeability in Fischer 344 rats of both sexes exposed to radio frequency electromagnetic fields. The exposure used 915 MHz microwaves delivered as either pulse-modulated or continuous wave signals. The rate of pathological leakage rose from 0.17 in controls to 0.39 across all exposed rats, a highly significant difference. Continuous wave exposure produced a higher rate of pathological rats (0.50 ± 0.07) than pulse-modulated exposure (0.35 ± 0.03), and that difference was also statistically significant.

Interactions of radiofrequency radiation on 2-methoxyethanol teratogenicity in rats

Nelson BK, Conover DL, Shaw PB, Snyder DL, Edwards RM · 1997

Researchers exposed pregnant rats to radiofrequency radiation that raised colonic temperature to 42.0°C for 10 minutes while administering various doses of 2-methoxyethanol on gestation day 13. Dose-related developmental toxicity from 2-methoxyethanol occurred both with and without the radiation exposure. However, the radiation changed the shape of the dose-effect curve for 2-methoxyethanol.

Mortality of plastic-ware workers exposed to radiofrequencies.

Lagorio S et al. · 1997

Researchers investigated the mortality of Italian plastic-ware workers exposed to radiofrequency fields from dielectric heat sealers. Follow-up ran from 1962 to 1992 and the analysis included 481 women workers representing 78% of person-years. Mortality from malignant neoplasms was slightly elevated and increased risks of leukemia and accidents were detected. The all-cancer standardised mortality ratio was higher among women in the sealing department than in the whole cohort.

[Evaluation of selected functional circulation parameters of workers from various occupational groups exposed to electromagnetic fields of high frequency. III. 24-h monitoring of arterial blood pressure].

Gadzicka E, Bortkiewicz A, Zmyslony M, Palczynski C · 1997

The study used 24-hour blood pressure monitoring with a Medilog ABP kit to assess male workers from middlewave broadcast stations, radioservice stations, and radio line stations. Mean arterial blood pressure and day-night blood pressure variability did not differ significantly between exposed and control groups. Daily heart rate was significantly lower in middlewave broadcast station workers compared to controls despite similar work and non-occupational activities. Day-night heart rate variability was significantly lower in exposed groups, which may suggest neurovegetative regulation disorders. Radioservice station workers had a higher incidence of increased arterial blood pressure than controls.

RF radiation-induced changes in the prenatal development of mice.

Magras, IN, Xenos, TD · 1997

Researchers measured RF power densities between 168 nW/cm2 and 1053 nW/cm2 at several locations around an antenna park. Twelve pairs of mice divided into two groups were placed in locations of different power densities and mated five times. The number of newborns per dam decreased progressively until irreversible infertility occurred, but crown-rump length, body weight, and vertebral counts improved.

Stress proteins are not induced in mammalian cells exposed to radiofrequency or microwave radiation.

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.

Ambulatory ECG monitoring in workers exposed to electromagnetic fields.

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.

Melatonin and a spin-trap compound block radiofrequency electromagnetic radiation-induced DNA strand breaks in rat brain cells.

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.

Naltrexone blocks RFR-induced DNA double strand breaks in rat brain cells

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.

Cancer morbidity in subjects occupationally exposed to high frequency (radiofrequency and microwave) electromagnetic radiation.

Szmigielski, S · 1996

Researchers compared cancer morbidity between occupationally exposed and non-exposed personnel using observed and expected rates to calculate an observed/expected ratio. The overall cancer morbidity rate was 119.1 per 100 000 annually in exposed personnel versus 57.6 in non-exposed, yielding an OER of 2.07 (P < 0.05). Higher rates were seen for alimentary tract neoplasms (OER = 3.19–3.24), brain tumours (OER = 1.91), and haemopoietic/lymphatic malignancies (OER = 6.31).

Sequential changes in cerebral blood flow, early neuropathological consequences and blood-brain barrier disruption following radiofrequency-induced localized hyperthermia in the rat.

Ohmoto Y et al. · 1996

Effects of pulsed high-frequency electromagnetic fields on human sleep.

Mann, K, Roschke, J · 1996

Researchers investigated the influence of pulsed high-frequency electromagnetic fields from digital mobile radio telephones on sleep in healthy humans. They found a hypnotic effect that shortened sleep onset latency and a REM suppressive effect that reduced REM sleep duration and percentage. Spectral analysis showed qualitative alterations of the EEG signal during REM sleep with increased spectral power density.

Experimental study of the effects of radiofrequency electromagnetic fields on animals with soft tissue wounds.

Detlavs I et al. · 1996

Researchers exposed Wistar rats with full-thickness dermal wounds to RF EMF for 30 min daily during the first 5 days using 53.53 GHz without modulation, 42.19 GHz without modulation, and 42.19 GHz with a 200-MHz frequency modulation band. RF EMF without frequency modulation decreased glycoprotein macromolecules and reduced inflammatory exudation and total collagen accumulation. RF EMF with frequency modulation significantly elevated hexoses and sialic acid concentrations, indicating intensified exudative phenomena, and increased collagenous protein accumulation. The authors concluded that non-thermal EMF affects reparative-proliferative processes in soft tissue wounds.

Heart rate variability in workers exposed to medium-frequency electromagnetic fields.

Bortkiewicz A, Gadzicka E, Zmyslony M, · 1996

The study compared 71 workers at medium-frequency broadcast stations with 22 non-exposed radio link station workers. Age and work tenure distributions did not differ significantly between groups. Heart rate variability was measured from 512 normal heart evolutions at rest using a Medea-HV system. Time-domain and frequency-domain HRV parameters showed no statistically significant differences between exposed and non-exposed groups. In the exposed group, maximum EM field intensity correlated negatively with high-frequency power spectrum.

[Evaluation of selected parameters of circulatory system function in various occupational groups exposed to high frequency electromagnetic fields. II.

Bortkiewicz A, Zmyslony M, Gadzicka E, Szymczak W · 1996

The study covered 71 workers at four AM broadcast stations, 40 workers at ten radio link stations, and 42 workers at three radioservices. Workers underwent subjective and objective medical examinations, resting electrocardiogram, Holter measurements, high intensity ECG, and long-term blood pressure recording for cardiac rhythm analysis. Exposure to EMF at AM broadcast stations increased the risk of electrographic disturbances six times in comparison with radio link station workers not exposed to medium wave EMF. Radioservice workers had twice the risk of electrographic disturbances compared to link station workers.

Assessment of radio-frequency electromagnetic radiation by the micronucleus test in bovine peripheral erythrocytes.

Balode, Z · 1996

Researchers examined micronuclei in bovine peripheral erythrocytes from female Latvian Brown cows near the Skrunda Radar and from a control area. They counted micronuclei in 2000 erythrocytes per animal at 1000x magnification using a simplified Schiff DNA staining method. The exposed group had an average of 0.6 micronuclei per 1000 erythrocytes versus 0.1 per 1000 in controls, a statistically significant difference (P < 0.01).

Effects of microwave and radio frequency electromagnetic fields on lichens.

Urech, M, Eicher, B, Siegenthaler, J · 1996

Researchers conducted field experiments lasting one to three years alongside laboratory tests, exposing Parmelia tiliacea and Hypogymnia physodes to 2.45 GHz microwaves at 0.2, 5, and 50 mW/cm² with a control. Both species showed a substantially reduced growth rate at the highest exposure of 50 mW/cm². Temperature measurements revealed that microwaves at 2.45 GHz and 50 mW/cm² substantially increased lichen surface temperature and accelerated drying. When the same species were exposed near a 9.5 MHz short-wave broadcast transmitter at up to 235 V/m, no visible effects were detected.

Effect of isothermal radiofrequency radiation on cytolytic T lymphocytes.

Cleary, SF, Du, Z, Cao, G, Liu, LM, McCrady, C · 1996

Researchers investigated the effects of RF radiation exposure on interleukin 2 (IL-2) -dependent proliferation of cytolytic T lymphocytes (CTLL-2). At specific absorption rates greater than 25 W/kg, exposure produced a consistent, statistically significant reduction in CTLL-2 proliferation, especially at low IL-2 concentrations. At lower SARs, 2450 MHz exposure increased CTLL-2 proliferation immediately after exposure but reduced 24 h postexposure proliferation. The researchers found significant qualitative and quantitative differences between the effects of temperature elevation and RF radiation.

Single- and double-strand DNA breaks in rat brain cells after acute exposure to radiofrequency electromagnetic radiation

Lai H, Singh NP · 1996

Researchers investigated single- and double-strand DNA breaks in rat brain cells after acute exposure to radiofrequency electromagnetic radiation. Rats received acute 2-hour exposure to pulsed or continuous-wave 2450-MHz radiofrequency electromagnetic radiation, producing a whole-body average-specific absorption rate of 1.2 W/kg. An increase in both types of DNA strand breaks was observed after exposure to either the pulsed or continuous-wave radiation, with no significant difference between the two forms.

Epidemiologic Evidence of Radiofrequency Radiation (Microwave) Effects on Health in Military, Broadcasting, and Occupational Studies

Unknown authors · 1995

This opinion piece reviews possible health effects of microwave or radar exposure in military, broadcasting, and occupational settings. The author notes that few studies have reliable dose estimates, none have accurate individual dosages, and none show tissue heating or short-term effects.

Absence of radiofrequency heating from auditory implants during magnetic resonance imaging.

Chou CK, McDougall JA, Can KW · 1995

Researchers tested the possibility of tissue heating from an auditory brainstem implant and a modified cochlear implant during MRI using a full-sized human phantom with simulated skull, brain, and muscle. Thermograms were taken before and after a 26-minute MRI scan with 94 excitations and 25 ms echo time set to induce maximum radiofrequency heating. Results showed no observable heating associated with either implant during worst-case MRI of the head.

[DNA analysis of retroposon-like genetic LINE elements in blood plasma of rats exposed to radio-diapason electromagnetic waves]

Belokhvostov AS et al. · 1995

The study aimed to investigate DNA analysis of retroposon-like genetic LINE elements in blood plasma of rats exposed to radio-diapason electromagnetic waves. The elevation of LINE-elements' DNA level was revealed in blood plasma of rats exposed to electromagnetic waves. The amount of full-size 5'-containing LINE-elements copies was increased especially. The researchers supposed a connection of this effect with retrotransposon activation and genetic instability condition of organism development.

Changes in the secondary structure of DNA under the influence of external low-intensity electromagnetic field

Semin IuA, Shvartsburg LK, Dubovik BV · 1995

Researchers studied the effect of weak radiofrequency radiation on DNA secondary structure stability in vitro. Exposure at 3 or 4 Hz and 0.6 mW/cm2 peak power significantly increased accumulated DNA damage, while other pulse rates or power levels eliminated the effect. DNA was incubated with glycine and formaldehyde, and damage was assessed via thermal denaturation dynamics.

Cell cycle alterations induced by isothermal 27 MHz radio-frequency radiation exposure.

Cao G, Liu LM, Cleary SF · 1995

Researchers exposed synchronized Chinese hamster ovary (CHO) cells to 27 MHz continuous-wave radio-frequency radiation for 2 hours at specific absorption rates of 5 or 25 W kg−1 under isothermal conditions, meaning no heating occurred. The exposure produced time- and dose-rate-dependent cell cycle alterations, with maximum responses occurring 3 days after exposure at a SAR of 25 W kg−1. Cells in G0/G1- or S-phase showed more pronounced alterations, while G2/M-phase cells showed minimal effects at either SAR.