EMF Research Studies

RF/Microwave Criteria Document Final Director's Draft Volume II: Chapter V-XII

Unknown authors

RF Susceptibility of Microelectronic Components

A. R. Hart, D. W. McQuitty, N. K. Wagner

Some Mathematical Considerations

J. Z. Hearon

THE EFFECTS OF 9-GHZ PULSED MICROWAVES ON CIRCULATING ANTIBODY TITERS OF MICE

Unknown authors

Researchers immunized female CD-1 mice against Streptococcus pneumoniae type III and exposed them to 9-GHz pulsed microwaves at 10 mW/cm² for two hours daily over five days. The mean antibody titer in irradiated mice was significantly higher than in sham-irradiated mice (means 24 versus 7.88, p=0.0025). When challenged with virulent bacteria, mortality was similar between the two groups (47.2% versus 50%).

The Effect of 2450 mc Radiation on the Development of the Chick Embryo

Claire Van Ummersen

SEARCH STRATEGY

Unknown authors

EFFECTS OF HYPERTHERMIA AND MICROWAVE INDUCED HYPERTHERMIC SHOCK ON HPC CELLS

Unknown authors

Researchers compared slow waterbath heating at 0.22°C per second with rapid microwave heating at 9.2°C per second before 15-minute hyperthermic exposures of human prostate cancer cells in vitro. The effect of the heating rate was small across the exposure range of 43.5 to 47.5°C. Microwave-induced hyperthermic shock followed by immediate waterbath cooling had no effect on cell survival below 43°C. Above 43°C, the percentage of cell survival decreased with increasing exposure temperature according to the linear relationship S = -11.6Tp + 593 with a correlation coefficient of 0.95. Effects were assayed by cellular attachment and colony formation and shown by SEM photography.

A TEMPERATURE MONITOR FOR MICROWAVE BIOEFFECTS RESEARCH AND ELECTROTHERMIA THERAPY

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COMPARISON OF EXPOSURE STANDARDS

Unknown authors

A SYSTEM FOR PRODUCING LOCALIZED HYPERTHERMIA IN BRAIN TUMORS THROUGH MAGNETIC INDUCTION HEATING OF FERROMAGNETIC IMPLANTS

Unknown authors

The researchers are developing a magnetic induction system to produce localized hyperthermia in intracranial tumors. Differential heating is achieved using small ferromagnetic seeds that can be stereotactically embedded in residual tumor during craniotomy. In phantom tests, Trial 16 showed a temperature differential greater than 4°C out to 1 cm from the implant site with no significant direct heating of the phantom by the RF field. Heating patterns in single seed phantoms matched the theoretically expected inverse radial distance dependence.

EVALUATION OF 915-MHZ AND 2450-MHZ DIRECT CONTACT DIATHERMY APPLICATORS

Unknown authors

The study evaluated three 915-MHz circularly polarized applicators. Heating patterns were measured in a bi-layered planar tissue model and compared with a 915-MHz linearly polarized applicator and a 2450-MHz circularly polarized applicator. The 915-MHz applicators achieved penetration depths of 2.8 to 3.1 cm in muscle versus 2.0 cm for the 2450-MHz applicator. Fat-to-muscle SAR ratios were 0.42 to 0.48 for 915-MHz applicators and about 1.0 for the 2450-MHz applicator.

DIFFERENTIAL CONSEQUENCES OF BIOLOGICAL SYSTEM EXPOSURE TO PULSED- AND CONTINUOUS-WAVE ELECTROMAGNETIC FIELDS

Unknown authors

Researchers exposed BALB/c female mice aged 10 to 14 weeks to pulsed- and continuous-wave electromagnetic fields at 432 MHz and 2450 MHz. Three modulations were used at each frequency: continuous wave, pulsed wave with a 120 microsecond pulse width at 400 Hz, and pulsed wave with a 12 microsecond pulse width at 4000 Hz. Power densities were 0.8 mW/cm² at 432 MHz and 2.14 mW/cm² at 2450 MHz. Two exposure schedules each provided 60 total hours: 2 hours daily for 30 consecutive days or 12 hours daily for 5 consecutive days. The study found no detectable bioeffects on granulopoietic stem cells under any exposure condition.

THERMAL AND ENDOCRINOLOGICAL EFFECTS OF MICROWAVE EXPOSURES ON RHESUS MONKEYS

Unknown authors

Researchers studied body temperature and hormone levels in chair-restrained adult male rhesus monkeys before, during, and after an 8-hour exposure to 1.29 GHz pulsed microwave radiation at 28 and 38 mW/cm². Rectal temperature increased by 0.6°C at 28 mW/cm² and 1.5°C at 38 mW/cm² compared to sham exposures, returning to baseline within 1-2 hours after exposure ended. No changes in circulating growth hormone, cortisol, or thyroxine levels were observed at any time during or after exposure despite the temperature rises.

EFFECTS OF 60 HZ ELECTRIC FIELDS ON RODENT ADRENAL TISSUE: IN VITRO AND IN VIVO

Scott N. Ackerman et al.

The in vitro response of adrenal cortical tissue to 60 Hz high intensity electric field exposure was studied. Adrenal glands were removed from male Sprague-Dawley rats and placed in physiological solution. Adrenal cortical tissue was sliced and placed in a superfusion system where corticosterone output was continuously monitored. An electric field exposure system was placed around the tissue at an initial strength of 45 kV/m and regularly incremented. The corticosterone output response to ACTH stimulation was compared between field-on and field-off conditions.

DOSIMETRIC USE OF SCHOTTKY DIODES

Unknown authors

Researchers examined the basic characteristics of microwave diodes including physical mechanisms and equivalent microwave circuits for dosimetric probe applications. Analytic expressions were developed that reveal linear, square-law, and other operating regions of the diodes. The effects of load resistance, bias current, and temperature on diode performance were explored. The analysis was applied to evaluate an E-field probe model designed for dosimetric use, comparing measurements with theory. Practical limitations on such probes were discussed and means of selecting diode parameters for maximum probe performance were presented.

STUDIES CONCERNING THE EFFECTS OF NON-THERMAL PROTRACTED PRENATAL 2450 MHz MICROWAVE IRRADIATION ON PRENATAL AND POSTNATAL DEVELOPMENT IN THE RAT

Unknown authors

Twenty-four Wistar rats were exposed 8 hours daily throughout pregnancy to 2450 MHz microwave radiation at 20 mW/cm². The exposure was non-thermal because rectal temperatures did not rise above control levels. Half of the rats were evaluated for teratologic effects on day 22 of gestation, and the other half raised offspring for postnatal behavioral and physiological testing. No significant alterations in prenatal or postnatal growth and development were observed.

THE EFFECT ON THE HEART RATE OF EMBRYONIC QUAIL OF 2450 MHz ELECTROMAGNETIC WAVES

Unknown authors

Researchers exposed Japanese quail embryos aged 8 to 13 days to 2450 MHz continuous-wave and pulsed electromagnetic waves at specific absorption rates from 0.3 to 30 mW/g. Heart rate was found to depend strongly on temperature, with a linear relationship between 36°C and 39°C. No effect of electromagnetic exposure on heart rate was observed beyond the changes caused by temperature.

Physical Agent: Radiofrequency

Unknown authors

Our Experience with Microwave Therapy

A. D. Golenberg et al.

MICROWAVE FEVER: AN ATTEMPT TO TRANSFER STREPTOCOCCAL ANTIBODY ACROSS THE CEREBROSPINAL-FLUID (CSF) BARRIER

Unknown authors

EFFECTS OF EXPOSURE TO 60 HZ ELECTRIC FIELDS ON GROWTH AND DEVELOPMENT IN THE RAT

Unknown authors

Considerations in the Evaluation of the Biological Effects of Exposure to Microwave Radiation

Stephen F. Cleary, William T. Ham, Jr.

TISSUE IMPEDANCE MEASUREMENTS USING THE MICROWAVE NETWORK ANALYZER

Unknown authors

The method uses a modified Roberts-von Hippel technique with a microwave network analyzer to measure the reflection coefficient from a tissue sample confined by a teflon plug in a precision coaxial line. Achieving high accuracy requires quarter-wavelength sample lengths, thickness measurement within 0.001 cm, and calibration against known terminations each time a sample is measured. Tests on distilled water, physiological saline, and methanol showed close agreement with known dielectric values, validating the technique.

THERMAL EFFECTS ON COLONIC AND REGIONAL BRAIN TEMPERATURE IN UNANESTHETIZED RATS EXPOSED TO 2450 MHz CW MICROWAVES

Unknown authors

Researchers monitored colonic temperature and temperatures in the cerebral cortex, hypothalamus, cerebellum, and medulla of unanesthetized rats that were either sham-exposed or exposed to 2450 MHz CW microwaves at 65 mW/cm² for 30 or 90 minutes. Regional brain and colonic temperatures were significantly higher in exposed rats than in sham controls after both exposure durations. In sham rats the mean cortical temperature was 36.6°C. After 30 minutes of exposure cortical temperature rose to 40.0°C and after 90 minutes to 42.1°C. Cortical and cerebellar temperatures were slightly lower than colonic temperature, while hypothalamic and medullary temperatures were slightly higher in all groups.

GLOBAL ATMOSPHERIC ELECTRIC GRADIENT VARIATIONS RELATE TO SURFACE HEAT FLUX

Unknown authors

The researchers analyzed hourly solar energy absorption by land and water surfaces using a world globe model. Land absorbs a significant portion of incident solar energy while water absorbs only about ten percent as sensible heat. The analysis revealed significant and surprisingly uniform variations in solar energy absorption between seasons and across 24-hour periods.