Study type: Medical/biological study (experimental study)

Detection-threshold of 50-Hz electric fields by human subjects. med./bio.

Published in: Bioelectromagnetics 1989; 10 (3): 319-327

Aim of study (acc. to author)

To study the threshold intensity for detection of an alternating current (AC) electric field in human subjects at different temperatures and humidities.

Background/further details

The palm and dorsum of the hand were exposed to fields, representing hairless and hairy skin, in order to clarify whether hair movement is critical for field detection.
Experiments were carried out during hot humid weather of July-August and dry cool air of October-November.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz

General information

Experiments took place during hot humid weather of July-August and dry cool air of October-November.

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Additional info vertical electric field
Exposure setup
Exposure source
Setup The upper brass electrode was held 20 mm above the lower aluminum electrode by two insulating posts. The electrodes were movable so that the vertical electric field could be applied on any part of the hand. The lower electrode and the human body were grounded. The lower electrode was in contact with the skin. In the experiments during October-November, hand or forearm was placed inside a small acrylic box (50 x 50 x 50 cm³).
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 115 kV/m unspecified calibration - October-November experiments
electric field strength 50 kV/m minimum calibration - august experiments
electric field strength 60 kV/m - calibration - august experiments
electric field strength 65 kV/m - calibration - august experiments
electric field strength 70 kV/m - calibration - august experiments
electric field strength 80 kV/m maximum calibration - august experiments
electric field strength 42.5 kV/m minimum calibration - july experiments
electric field strength 50 kV/m - calibration - july experiments
electric field strength 55 kV/m maximum calibration - july experiments
electric field strength 10 kV/m minimum calibration - applied in coarse steps to estimate threshold
electric field strength 30 kV/m minimum calibration - applied in coarse steps to estimate threshold
electric field strength 50 kV/m minimum calibration - applied in coarse steps to estimate threshold
electric field strength 70 kV/m minimum calibration - applied in coarse steps to estimate threshold
electric field strength 90 kV/m maximum calibration - applied in coarse steps to estimate threshold

Reference articles

  • Kato M et al. (1986): Response of sensory receptors of the cat's hindlimb to a transient, step-function DC electric field.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

Threshold values obtained in the summer were 30-65 kV/m for the hairy skin on the dorsum of the hand, while for the hairless skin on the palm the threshold was greater than 115 kV/m (highest field available due to limitations of the power supply).
During the fall, the threshold was much higher than during the summer (humidity was the main factor for this difference).

Study character:

Study funded by

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