Medical/biological study (experimental study, theoretical study, review/survey)

Perception of ELF electromagnetic fields: excitation thresholds and inter-individual variability med./bio.

By: Leitgeb N, Schröttner J, Cech R

Published in: Health Phys 2007; 92 (6): 591-595

Aim of study (acc. to editor)

To study the perception threshold of extremely low frequency electromagnetic fields in 1,071 individuals (349 men and 359 women aging 16 to 60 years, 117 girls and 123 boys aging 9 to 16 years, and 123 individuals older than 60 years).

Background/further details

The survey discusses the results of author's previous research (see "related articels" et al.).

Endpoint

effects on the neurological system: perception threshold

Exposure

- 50/60 Hz
- touch current
- electric current application

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: current linearly increased until perception of current	current density: 9.9 µA/cm² minimum (for women) current density: 209 µA/cm² maximum (for women) current density: 43.7 µA/cm² minimum (for men) current density: 248 µA/cm² maximum (for men) current density: 14.4 µA/cm² minimum (for children) current density: 187 µA/cm² maximum (for children) current: 15 µA min. value

Exposure 1

Main characteristics

Frequency	50 Hz
Type	electric current
Exposure duration	current linearly increased until perception of current

Exposure setup

Exposure source	conventional circular pre-geled ECG-Ag/AgCl electrodes
Setup	electrodes on both forearms of the test persons

Parameters

Measurand	Value	Type	Method	Mass	Remarks
current density	9.9 µA/cm²	minimum	calculated	-	for women
current density	209 µA/cm²	maximum	calculated	-	for women
current density	43.7 µA/cm²	minimum	calculated	-	for men
current density	248 µA/cm²	maximum	calculated	-	for men
current density	14.4 µA/cm²	minimum	calculated	-	for children
current density	187 µA/cm²	maximum	calculated	-	for children
cf. remarks	-	-	-	-	current: 15 µA min. value

Exposed system:

human
partial body: forearms

Methods Endpoint/measurement parameters/methodology

effects on the neurological system: perception threshold of touch currents (inter-individual variability discussion of previous study results)
calculation of intracorporal electric current densities associated with the applied electric currents (numerical simulations)

Investigated system:

investigation on living organism

Investigated organ system:

Time of investigation:

during exposure

Main outcome of study (acc. to author)

Women were found to be significantly more sensitive than men. Children turned out to be more sensitive than men but similar to women. An analysis of the age dependence showed that both boys and girls were similarly sensitive to electric currents at ages 9 to 11 years. The data indicate that existing safety limit values for touch currents need critical review.
Numerical simulations confirmed that the basic limit values of intracorporal electric current densities as recommended by ICNIRP are conservative to prevent cellular excitation.

Study character:

medical/biological study
experimental study
theoretical study
review/survey
full/main study
double-blind study

Study funded by

not stated/no funding

Schröttner J et al. (2007): Investigation of electric current perception thresholds of different EHS groups
Leitgeb N et al. (2006): Electric current perception of children: the role of age and gender
Leitgeb N et al. (2005): Electric current perception of the general population including children and the elderly
Leitgeb N et al. (2002): Electric current perception study challenges electric safety limits
Leitgeb N et al. (2001): [Electric current is more hazardous than previously assumed]
Flühr H et al. (1997): [Perception of electrical alternating currents by thermal effects]
Irnich W et al. (1989): [The perception threshold for 50 Hz alternating voltage and current]