Study type: Medical/biological study (experimental study)

Models of long-range order in cerebral macromolecules: Effects of sub-ELF and of modulated VHF and UHF fields med./bio.

By: Sheppard AR, Bawin SM, Adey WR
Published in: Radio Sci 1979; 14: 141-145
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Aim of study (acc. to author)

To investigate the effects of a 450 MHz, 16 Hz AM modulated RF exposure on the calcium efflux from chicken brain in vitro.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 450 MHz
Modulation type: AM
Exposure duration: continuous for 20 min

Exposure 1

Main characteristics
Frequency 450 MHz
Type
Charakteristic
  • guided field
Polarization
Exposure duration continuous for 20 min
Modulation
Modulation type AM
Modulation frequency 16 Hz
Modulation depth 90 %
Additional info

sinusoidal
Exposure setup
Exposure source
  • TEM chamber
Distance between exposed object and exposure source 3 m
Chamber The copper-screened tapered chamber operating in TEM mode was lined with RF-absorbing material and maintained at 36 °C and about 40% humidity.
Setup Chick half brains were exposed in plastic tubes containing 1 ml of non-radioactive physiological solution.
Parameters
Measurand Value Type Method Mass Remarks
power density 0.05 mW/cm² - measured - -
power density 0.1 mW/cm² - measured - -
power density 1 mW/cm² - measured - -
power density 2 mW/cm² - measured - -
power density 5 mW/cm² - measured - -
Measurement and calculation details

Evaluation of the chamber showed adequate field uniformity, linearity of polarization, and low SWR. Routine checks were made using a miniature isotropic field meter and a power meter.

Reference articles

  • Bawin SM et al. (1976): Sensitivity of calcium binding in cerebral tissue to weak environmental electric fields oscillating at low frequency

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The calcium efflux from chicken brain tissue was increased by 450 MHz RF exposure AM modulated at 16 Hz. The efflux occured at power densities between 0.05 mW/cm2 and 1.0 mW/cm2.

Study character:

Study funded by