Human exposure to 60-Hz magnetic fields: neurophysiological effects.
The neurophysiological effects of exposure to power-frequency magnetic fields at two occupationally-relevant intensities were evaluated in a single-blind study with 18 male and 18 female volunteers. Auditory brainstem (BAEP) and somatosensory (SEP) evoked potentials were recorded before, during and after field exposure (duration = 45 min, frequency = 60 Hz, field intensities = 14.1 or 28.3 microtesla, microT), or an equivalent sham-exposure control period. Visual event-related potentials (VEP) to pattern reversal stimuli were also recorded before and after the exposure period. Field exposure had no differential effects on the BAEP, the VEP, or on SEP measures of central conduction time. Men and women showed a similar lack of sensitivity to exposure. The present results do not support the mechanistic hypothesis that the transmission of sensory information to appropriate cortical centers is delayed or distorted by exposure to power-frequency magnetic fields at occupational intensities.
Graham
C
C
Midwest Research Institute, Kansas City, Missouri 64110, USA. cgraham@mriresearch.org
Cook
M R
MR
Cohen
H D
HD
Riffle
D W
DW
Hoffman
S
S
Gerkovich
M M
MM
D000293:Adolescent; D000328:Adult; D004574:Electromagnetic Fields / Q000009:adverse effects*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009424:Nervous System Physiological Phenomena / Q000528:radiation effects*; D010364:Pattern Recognition, Visual / Q000502:physiology; D016037:Single-Blind Method; D009435:Synaptic Transmission / Q000502:physiology