Study type: Medical/biological study (experimental study)

Effects of ELF (1-120 Hz) and modulated (50 Hz) RF fields on the efflux of calcium ions from brain tissue in vitro med./bio.

By: Blackman CF, Benane SG, House DE, Joines WT
Published in: Bioelectromagnetics 1985; 6 (1): 1-11
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Aim of study (acc. to author)

To investigate the effects of extremely low frequency (1-120 Hz) and AM modulated radiofrequency exposure (50 MHz, 50 Hz modulated) on the calcium efflux in chicken brain tissue.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 42–60 Hz
Exposure duration: continuous for 20 min
Exposure 2: 1–120 Hz
Exposure duration: continuous for 20 min
Exposure 3: 50 MHz
Modulation type: AM
Exposure duration: continuous for 20 min
  • power density: 2.3 mW/cm² maximum (1.96 mW/cm², 1.86 mW/cm² and 1.56 mW/cm²)

Exposure 1

Main characteristics
Frequency 42–60 Hz
Type
Waveform
Exposure duration continuous for 20 min
Additional info Exposure to 42 Hz, 45 Hz, 48 Hz, 50 Hz and 60 Hz electric fields.
Exposure setup
Exposure source
Setup Samples in sealed tubes were placed in racks arranged symmetrically on either side of the center conductor in the transmission line maintained at 37°C. Transmission line was aligned with its long axis vertical.
Additional info For control, tubes were placed in a water bath maintained at 37°C.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 55 V/m peak value measured - 50 V/m, 45 V/m, 40 V/m, 35 V/m and 30 V/m; at 45 Hz
electric field strength 40 V/m peak value measured - at 48 Hz
electric field strength 60 V/m peak value measured - 50 V/m, 40 V/m and 30 V/m; at 42 Hz
electric field strength 65 V/m peak value measured - 60 V/m, 55 V/m, 50 V/m, 45 V/m, 40 V/m, 35 V/m and 30 V/m; at 50 Hz
electric field strength 45 V/m peak value measured - 40 V/m, 35 V/m, 30 V/m and 25 V/m; at 60 Hz
Additional parameter details

Theoretically, the corresponding magnetic field component (A/m) is equal to electric field intensity (V/m effective value = peak to peak value divided by 2.828) divided by 377.

Exposure 2

Main characteristics
Frequency 1–120 Hz
Type
Waveform
Exposure duration continuous for 20 min
Additional info Exposure to 1 Hz, 15 Hz, 30 Hz, 45 Hz, 60 Hz, 75 Hz, 90 Hz, 105 Hz and 120 Hz electric fields.
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 42.5 V/m peak value measured - -

Exposure 3

Main characteristics
Frequency 50 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 20 min
Modulation
Modulation type AM
Modulation frequency 50 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 2.3 mW/cm² maximum measured - 1.96 mW/cm², 1.86 mW/cm² and 1.56 mW/cm²

Reference articles

  • Blackman CF et al. (1980): Induction of calcium-ion efflux from brain tissue by radiofrequency radiation: effect of sample number and modulation frequency on the power-density window

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Radiofrequency exposure leads to an significantly increased calcium efflux at power densities of 1.86 and 1.96 mW/cm2.
No efflux was observed at fields between 1 and 42 Hz. A 45 Hz field enhanced the calcium efflux in an intensity range around 40 Vp-p/m (volts peakt-to-peak per meter). A 50 Hz field enhanced the calcium efflux in an intensity region between 45 and 50 Vp-p/m.

Study character:

Study funded by

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