Human exposure to 60-Hz magnetic fields: neurophysiological effects

The neurophysiological effects of exposure to power-frequency magnetic fiel ds at two occupationally-relevant intensities were evaluated in a single-bl ind 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 intensiti es = 14.1 or 28.3 microtesla, mu T), 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 centra l conduction time. Men and women showed a similar lack of sensitivity to ex posure. 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 occu pational intensities. (C) 1999 Elsevier Science B.V. All rights reserved.