Medical/biological study (experimental study)

The Short-Term Effect of Occupational Levels of 50 Hz Electromagnetic Field on Human Heart Rate Variability med./bio.

By: Binboğa E, Tok S, Munzuroğlu M

Published in: Bioelectromagnetics 2021; 42 (1): 60-75

Aim of study (acc. to author)

The effects of a short‐term effect exposure of healthy males to a 50 Hz magnetic field on heart rate and heart rate variability should be investigated.

Background/further details

Healthy males were randomly assigned to an exposure group (n=17) and sham exposure group (n=17).

Endpoint

effects on the cardiovascular system: heart rate and heart rate variability

Exposure

- 50/60 Hz
- magnetic field
- occupational

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: 5 minutes	magnetic flux density: 28 µT (±2 μT; at the heart position) magnetic flux density: 4 µT (±1 μT; at the head position)

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Waveform	sinusoidal
Polarization	linear
Exposure duration	5 minutes

Exposure setup

Exposure source	Helmholtz coils
Chamber	specially prepared, quiet room with an ambient temperature of 25°C
Setup	coils were made of 2 mm copper wire wound on a 70 cm diameter circular frame, with 350 turns per coil; epoxy was layered between the loops to glue them together to minimize vibration noise when the coils were activated; the two coils were mounted 35 cm apart on a wooden framework so that the magnetic field was horizontal; the participants were asked to lie supine on a wooden stretcher placed in the center of the Helmholtz coil system to provide a homogeneous 15 × 15 × 15 cm³ magnetic field area in the participants' heart region
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	28 µT	-	measured	-	±2 μT; at the heart position
magnetic flux density	4 µT	-	measured	-	±1 μT; at the head position

Additional parameter details

the magnetic flux density of 28 (±2) μT is within the range of exposure often associated with electric utility operations and the use of industrial machinery or power equipment; the intensity of the ambient static field in the room was 15 μT along the horizontal axis and 44 μT along the vertical axis; the ambient 50 Hz magnetic flux density ranged from 0.008 to 0.02 μT (average: 0.01 μT)

Exposed system:

human
partial body: chest

Methods Endpoint/measurement parameters/methodology

effects on the cardiovascular system: heart rate and heart rate variability (standard deviation of RR intervals (SDNN), root mean square of successive RR interval differences (RMSSD), low frequency power (LF), high frequency power (HF), LF/HF ratio (LF/HF); photoplethysmography)

Investigated system:

investigation on living organism

Investigated organ system:

cardiovascular system

Time of investigation:

before exposure
during exposure
after exposure

Main outcome of study (acc. to author)

SDNN, RMSSD, LF and HF were significantly increased in the exposure group compared to the sham exposure group during the exposure to the magnetic field.
The authors concluded that short‐term effect exposure of healthy males to a 50 Hz magnetic field could influence heart rate variability indicating a possible enhancement of parasympathetic predominance.

Study character:

medical/biological study
experimental study
full/main study
double-blind study

Study funded by

Ege University, Turkey

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