Whole Body / General

Experimental research on the biological action of the pulse-modulated microwave radiation created by shipboard radar stations

Kaliada TV et al. · 1995

[Some biochemical indexes in white rabbit's blood affected by acute high intensity microwave].

Li C et al. · 1995

The study aimed to investigate biochemical indexes in white rabbit blood affected by acute high-intensity microwave. The researchers stated these changes can be used as indexes for evaluating acute high-intensity microwave exposure effects.

Circularly polarized 50-Hz magnetic field exposure reduces pineal gland and blood melatonin concentrations of Long- Evans rats

Unknown authors · 1994

Exposure limits for ultra-short wave radiation in work environments.

Zhao Z, Zhang S, Wang S, Yao Z, Zho H, Tao S, Tao L · 1994

The study aimed to investigate exposure limits for ultra-short wave radiation in work environments. Eighteen male rabbits were divided into four groups; three groups were irradiated with ultra-short waves at 100 MHz at power densities of 35, 1.5-3.5, and 0.07 mW/cm2 for 3 hours per day, 5 days per week for 24 weeks. Thermal effects occurred at 35 mW/cm2 and the thermal threshold limit value was set at 1.5 mW/cm2. An epidemiological survey of 136 factory workers and TV operators exposed to 0.2 mW/cm2 for over one year was compared with 108 controls. The exposure limit value for short wave radiation was set at 0.2 mW/cm2 using 15- and 20-fold safety factors.

The effects of radiofrequency (< 30 MHz) radiation in humans.

Zhao Z, Zhang S, Zho H, Zhang S, Su J, Li L, · 1994

Researchers examined 121 workers exposed to radiofrequency radiation below 30 MHz for over one year, divided into high-intensity (>=100 V/m) and low-intensity (<100 V/m) groups compared to controls. No significant changes in autonomic nervous system functioning or blood parameters (hemoglobin, white blood cells, platelets) occurred in either exposed group. However, ECG changes including ST-T interval alterations and abnormal heart rate were observed in the high-intensity exposure group. The authors suggested 100 V/m as an exposure limit for radiofrequency radiation below 30 MHz.

Effects of modulated microwave and X-ray irradiation on the activity and distribution of Ca(2+)-ATPase in small intestine epithelial cells

Somosy Z, Thuroczy G, Koteles GJ, Kovacs J · 1994

Researchers investigated the distribution and activity of Ca(2+)-ATPase in small intestine epithelial cells of mice after total body exposure to 2450 MHz microwave irradiation modulated at 16 Hz and X-ray irradiation. In control animals, enzyme activity was present in the brush border and lateral membranes, and lateral membrane activity was inhibited by quercetin. Microwave irradiation immediately decreased Ca(2+)-ATPase activity on lateral membranes, 1 Gy X-ray caused a similar reversible decrease within 24 hours, and 5 Gy X-ray reduced activity on both apical and lateral membranes persisting up to 24 hours.

Alteration of life span of mice chronically exposed to 2.45 GHz CW microwaves.

Liddle CG, Putnam JP, Huey OP · 1994

Female CD1 mice were exposed from the thirty-fifth day of age for the remainder of their lives to 2.45 GHz CW microwave radiation at 3 or 10 mW/cm2. Exposures took place 1 h/day, 5 day/week in an anechoic chamber at an ambient temperature of 22 degrees C and a relative humidity of 50%. There were 25 animals in each exposure group, and an equal number of controls were concurrently sham exposed. The average life span of animals exposed at 10 mW/cm2 was significantly shorter than that of sham-exposed controls (572 days vs. 706 days; P = .049; truncation > 20%). In contrast, the average lifespan of the animals exposed at 3 mW/cm2 was slightly, but not significantly, longer (738 days) than that of controls (706 days).

SAR calculations in an anatomically realistic model of the head for mobile communication transceivers at 900 MHz and 1.8 GHz.

Dimbylow PJ, Mann SM. · 1994

Researchers built a mathematical model of the human head from MRI slices and used finite-difference time-domain (FDTD) calculations to estimate the specific energy absorption rate (SAR) at 900 MHz and 1.8 GHz. The generic transceiver was represented by a quarter-wavelength monopole on a metal box, and three placement geometries were examined: vertical in front of the eye, and vertical and horizontal at the side of the ear. For the most typical position at the side of the head, the maximum SAR averaged over 10 g of tissue was 2.1 and 3.0 W kg(-1) per W of radiated power at 900 MHz and 1.8 GHz. Placement in front of the eye gave values of 3.1 and 4.6 W kg(-1) per W averaged over 10 g of tissue at 900 MHz and 1.8 GHz.

Characteristics of microwave evoked body movements in mice.

Brown DO, Lu ST, Elson EC · 1994

Researchers studied microwave evoked body movements in mice using head and neck exposure to pulsed and gated continuous wave 1.25 GHz microwaves delivered via a resonant cavity. The incidence of body movements increased proportionally with specific absorption dose when the whole-body average specific absorption rate was held constant at 7300 W/kg, reaching a plateau at 0.9 kJ/kg. For doses higher than 0.9 kJ/kg, response incidence was proportional to the specific absorption rate and reached a plateau at 900 W/kg.

Modification of lethal radiation injury in mice by postradiation exposure to low-intensity centimeter-band radio frequency waves

Akoev IG, Mel'nikov VM, Usachev AV, Kozhokaru AF, · 1994

Researchers studied whether exposure to low-intensity radiofrequency radiation after a lethal dose of gamma-radiation could modify the resulting injury in mice. The radiofrequency exposure lasted up to 23 hours at an intensity of 5 plus or minus 1.5 microwatts per square centimeter, covering frequency ranges of 2-8, 8-18, and 19-27 GHz with a swing frequency of 12-14 Hz. A clearly pronounced modification of acute radiation injury was obtained when the radiofrequency exposure was applied immediately after the gamma-radiation.

[Changes in drug pharmacokinetics and pharmacodynamics under the influence of microwaves of different ranges].

Ulashchik VS · 1993

The study aimed to investigate changes in drug pharmacokinetics and pharmacodynamics under the influence of microwaves of different ranges. Human and animal experiments were conducted to compare the effect of microwaves of different ranges on drug pharmacodynamics and pharmacokinetics. The results suggested that microwaves could potentiate and prolong the action of some drugs.

[Eye heating caused by microwave ovens].

Leitgeb N, Tropper K · 1993

Researchers investigated a worst-case scenario where a child observes the microwave oven interior with eyes as close to the door as possible. Significant microwave heating occurred only when safety contacts were inactivated and the door was opened. At a 2.3 cm door gap, microwaves contributed no more than 16% of a 5°C temperature rise after one hour, and at a 2.6 cm gap they contributed 50% of a 2°C rise after 15 minutes.

Visual abnormalities associated with high-energy microwave exposure.

Lim JI, Fine SL, Kues HA, Johnson MA. · 1993

The study investigated visual abnormalities associated with high-energy microwave exposure. A 44-year-old man was accidentally exposed to high-energy microwave irradiation and later reported a foreign body sensation and blurring of vision. Electroretinogram testing revealed a marked decrease in the flicker electroretinogram, and color vision tests were abnormal. Two years later, visual acuity was stable at 20/25 in both eyes, but the flicker electroretinogram remained markedly decreased.

Health status of personnel occupationally exposed to radiowaves.

Goldoni J, Durek M, Koren Z · 1993

Researchers examined two groups of workers occupationally exposed to microwaves and radiofrequency radiation and compared them with a control group. One group consisted of 49 radar operators from Zagreb Air Traffic Control who were examined twice over 18 months, and the other group comprised 46 workers at radio relay stations. A follow-up study found significant changes in haematological and biochemical parameters, electrical brain activity, and capillaroscopic and ophthalmological findings in the radar operators, and a cross-sectional analysis showed the highest rate of changes in general health status for that group.

Effects of modulated and continuous microwave irradiation on pyroantimonate precipitable calcium content in junctional complex of mouse small intestine.

Somosy Z, Thuroczy G, Kovacs J · 1993

Researchers investigated pyroantimonate-precipitable calcium in mouse intestinal epithelial cells after whole-body exposure to 2450 MHz continuous and 16 Hz square-modulated microwaves. Immediately after modulated irradiation at 0.5 and 1 mW/cm², calcium deposits rapidly appeared on the cytoplasmic side of lateral membranes and in the junctional complex including tight junctions. These changes were reversible, with calcium distribution returning to control-like patterns after 24 hours. Continuous-wave exposure at the same energy did not alter calcium distribution.

Differential response of the permeability of the rat liver canalicular membrane to sucrose and mannitol following in vivo acute single and multiple exposures to microwave radiation (2.45 GHz) and radiant-energy thermal stress.

Lange DG, D'Antuono ME, Timm RR, Ishii TK, Fujimoto JM. · 1993

Naltrexone-sensitive analgesia following exposure of mice to 2450-MHz radiofrequency radiation

Maillefer RH, Quock RM · 1992

Male Swiss Webster mice were exposed to 10, 15, and 20 mW/cm2 RFR at 2450 MHz for 10 minutes at SARs of 23.7, 34.6, and 45.5 W/kg, then tested in the abdominal constriction paradigm. Confinement alone did not appreciably alter body temperature but appeared to induce stress-associated analgesia that was not blocked by naltrexone. RFR exposure raised body temperature and further increased analgesia in an SAR-dependent manner. The high SAR-induced analgesia was blocked by naltrexone, but the hyperthermia was not.

Increased sensitivity of the non-human primate eye to microwave radiation following ophthalmic drug pretreatment.

Kues HA et al. · 1992

Researchers exposed anesthetized monkeys to pulsed 2.45 GHz microwaves after topical treatment with timolol maleate or pilocarpine. Drug pretreatment lowered the power-density threshold for corneal endothelial lesions and increased iris vascular permeability from 10 to 1 mW/cm². Effects occurred at an average SAR of 0.26 W/kg and were confirmed with specular microscopy, fluorescein angiography, and horseradish peroxidase tracer techniques.

Foot currents and ankle SARs induced by dielectric heaters.

Conover DL et al. · 1992

Researchers measured foot currents in workers who stood at their normal operating positions near industrial dielectric heaters generating fields at frequencies from 6.5 to 65 MHz. Nearly 27 percent of the heaters induced foot currents exceeding the proposed 200-mA ANSI C95.1 limit, and 20 percent exceeded 350 mA. Specific absorption rates in ankles were calculated from foot currents and approximated 5 W/kg at 100 mA, 29 W/kg at 250 mA, and 57 W/kg at 350 mA, with a maximum of approximately 176 W/kg at 617 mA.

Long-term, low-level microwave irradiation of rats.

Chou CK, Guy AW, Kunz LL, Johnson RB, Crowley JJ, Krupp JH · 1992

Two hundred male Sprague-Dawley rats were assigned in equal numbers to radiation-exposure and sham-exposure conditions, with exposure beginning at 8 weeks of age and continuing daily for 25 months. The experimental rats were exposed to 2,450-MHz pulsed microwaves at 800 pps with a 10-microseconds pulse width, square-wave modulated at 8-Hz. Blood samples were analyzed at regular intervals for serum chemistries, hematological values, protein electrophoretic patterns, thyroxine, and plasma corticosterone levels.

Physiological interaction processes and radio-frequency energy absorption.

Adair ER, Adams BW, Hartman SK · 1992

Researchers exposed adult male squirrel monkeys to 450-MHz or 2,450-MHz continuous-wave fields in cool environments to study how the body responds to radio-frequency heating. During brief exposures in the cold, the reduction of metabolic heat production was directly proportional to the SAR, and 2,450-MHz energy was a more efficient stimulus than the resonant frequency. In the steady state, exposure at the resonant frequency produced a regulated increase in deep body temperature, described as not unlike that which occurs during exercise. Researchers concluded that skin temperature changes are the primary source of the neural signal for a change in physiological interaction processes during radio-frequency exposure in the cold.

[Hematologic changes in workers exposed to radio wave radiation].

Budinscak V, Goldoni J, Saric M · 1991

Researchers measured hematological parameters in 43 radar operators employed in air traffic control who were occupationally exposed to microwave radiation of low intensity over four years. Exposed workers showed decreased erythrocytes, reticulocytes, platelets, segmented granulocytes and monocytes, and increased leucocytes and lymphocytes. The changes were not pathologically significant and most of them were reversible.

Thermal and metabolic responsiveness of Japanese quail embryos following periodic exposure to 2,450 MHz microwaves.

Spiers DE, Baummer SC · 1991

Researchers exposed Japanese quail eggs to 2,450 MHz microwaves at 5 or 20 mW/cm² for 8 hours daily from day 1 to 15 of incubation. At 30 °C ambient temperature, microwave exposure increased wet-embryo mass on day 16 by 9% at 5 mW/cm² and 61% at 20 mW/cm² compared to predicted masses without microwaves. Post-treatment tests showed no reliable indication that repeated microwave exposure resulted in abnormal physiological development. The authors concluded that microwave radiation can increase egg temperature and embryonic growth rate at below-normal incubation temperatures without altering basic metabolic and thermal characteristics.

[The participation of thyroid hormones in modifying the mutagenic effect of microwaves].

Koveshnikova IV, Antipenko EN · 1991

Researchers studied whether thyroid hormones play a role in modifying the mutagenic effect of microwaves in rats. The mutagenic effect of microwaves at 2,450 or 2,750 MHz, 500 microW/cm2, for 30 days at 7 hours a day increased when rats had either low or high thyroid hormone levels. The researchers concluded that normal thyroid gland functioning appears to be an important condition for maintaining chromosome integrity under microwave exposure.

Immediate post-exposure effects of high-peak-power microwave pulses on operant behavior of Wistar rats.

Akyel Y, Hunt EL, Gambrill C, Vargas C Jr, · 1991

Researchers studied the behavioral effects of high-peak-power microwave pulses on Wistar rats trained to press a lever for food pellets. Each animal was exposed for 10 min to 1.25-GHz microwave radiation at 1-MW peak-power, with total doses set to 0.50, 1.5, 4.5, and 14 kJ/kg. At the highest dose, rats showed an average colonic temperature rise of 2.5 °C and failed to respond for about 13 minutes after exposure. No behavioral effects were found at the lower dose levels, and researchers concluded the effects were thermal in nature.