Research into the hypothetical adverse effects on health that might result from living or working in the proximity of high-voltage power lines has been intense over the last decade. The present paper provides a brief review of the human studies concerned with the physiological and psychological effects of exposure to extremely low-frequency electric and magnetic fields. It was concluded that, on the basis of available experience, electric and magnetic fields associated with transmission lines do not cause physiological or psychological effects to be considered as health hazards.