EMF Research Studies

Physical Agent: Radiofrequency

Unknown authors

Our Experience with Microwave Therapy

A. D. Golenberg et al.

EXPERIMENTAL AND ANALYTICAL STUDY ON INTERACTION BETWEEN NEAR-ZONE EM FIELD OF CB-RADIO ANTENNA AND HUMAN BODY

Unknown authors

Tissue Temperature as a Consideration in the Development of Radiofrequency Exposure Standards

R. A. Tell, F. Harlen

The authors used dosimetric and thermoregulatory data to develop a rationale for thermally based RF exposure safety standards limiting both core and local tissue temperature rise to 1°C. They found that if local tissue temperature rise is limited to 1°C, the rectal temperature rise is automatically limited to 0.05°C. The permissible exposure levels are frequency dependent with a minimum of 1.6 mW/cm² in the body resonance region (30-300 MHz) and 10 mW/cm² for frequencies above 2 GHz. Data show these limits need not be modified for most heat stressing environmental conditions.

ELECTRIC AND MAGNETIC FIELD INTENSITIES AND ASSOCIATED INDUCED BODY CURRENTS IN MAN IN CLOSE PROXIMITY TO A 50 KW AM STANDARD BROADCAST STATION

Unknown authors

The wave impedance dropped to less than half the far-field value of 377 ohms at distances under 150 m. Body current was measured by placing a person on a ground plane 15 cm above earth and detecting voltage across a known resistor. Measured body currents showed excellent agreement with theoretical values from a prolate spheroidal model of a human on a conductive ground plane.

RADIOFREQUENCY RADIATION EXPOSURE STANDARDS

Unknown authors

Effects of currents of different parameters on the CNS during EA

K. I. Kuz'mina, N.P. Irodova, L. Yu. Rabichev

Kuz'mina and Irodova reported effects of currents on the CNS during EA and developed a "Mix" procedure with three currents of different frequencies and shapes. They reportedly obtained superior results compared to conventional EA procedures using pulse current plus bias or interference current.

ANALYSIS OF MAGNETICALLY-INDUCED POTENTIALS AND CURRENTS AROUND THE ASCENDING AORTA

Y. Kinouchi, Y. Kubo, T. Ushita, T.S. Tenforde

The model solved simultaneous equations for blood flow velocity distribution and induced electric fields. With a 1 Tesla field and peak aortic flow of 60 cm/s, the induced potential on the thoracic surface near the breasts was about 1 mV, large enough to appear on an electrocardiogram. Induced current densities were about 0.05 A/m² on the vascular wall and 0.02 A/m² 1 cm from the aorta, far below the 1.7 A/m² ventricular fibrillation threshold.

EFFETS BIOLOGIQUES DES RAYONNEMENTS ELECTROMAGNETIQUES U.H.F. (radars)

R. JOLY, B. SERVANTIE

EXPOSURE LIMITS FOR MICROWAVE RADIATION - A CANADIAN PROPOSAL

Michael H. Repacholi

ELABORATION OF A VASCULAR CONDITIONED REFLEX IN MAN TO A CHANGE IN THE TENSION OF AN ELECTROMAGNETIC FIELD OF HIGH FREQUENCY

G. F. Plakhanov, V. V. Vedyushkina

Seven healthy volunteers aged 20-23 years underwent more than 100 plethysmographic tests while exposed to a high frequency field from a DTP diathermy apparatus. The stimulus manipulations did not change the apparatus sound, and calculated temperature rises and induced currents from field changes were far below biological and ambient levels, leading the authors to conclude the field intensity change was the conditioned stimulus.

Microwave Radiation Hazards

Morgan

Microwaves originate as electro-magnetic impulses in a high frequency oscillator tube with relatively short wavelengths. The waves are carried through a wave guide to a transmitting antenna which ejects them into space at the speed of light. Invisible microwaves such as radar can ignite steel wool, set off photo-flash bulbs, and ignite fuel vapors. Reports and rumors of fearsome side effects on persons exposed to microwave radiation from radar beams have more than once found an interested audience. To eliminate such rumors, a basic understanding of microwave radiation is needed by personnel in the field of health protection.

NEAR-FIELD IRRADIATION OF CYLINDRICAL MODELS OF HUMANS AND ANIMALS

Unknown authors

The study calculated the specific absorption rate (SAR) in infinitely long cylindrical models of humans and animals irradiated by the near fields of short dipoles. The method used electric and magnetic Hertzian potentials and overcame numerical integration difficulties by expanding integrals in terms of Hermite polynomials. Numerical results for a dipole at one wavelength distance showed good agreement with planewave irradiation results. The authors plan to present SAR for different models as a function of frequency, incident power density, and electric and magnetic energy densities.

TRANSCUTANEOUS ELECTROMAGNETIC FLOWMETRY: VOLTAGE DISTRIBUTION IN A BLOOD VESSEL - LIMB SEGMENT CYLINDRICAL MODEL

Unknown authors

The method uses a concentric three-media cylindrical model to estimate popliteal artery flow from skin surface voltages. Subjects lie supine with the leg in a 16 cm magnetic pole gap while EEG electrodes detect voltages under 100 µV for less than two minutes. In an example with 100 cc/min flow, the maximum skin voltage was 5 µV while the maximum vessel voltage reached 86 µV. Calculated current densities were well below levels known to excite membranes or damage blood, and subjects reported no sensation.