Sierra Pacific Power Co. Environmental Affairs Dept. Magnetic fields result from the flow of current through the wires or electrical devices. The magnetic fields increase in strength as the current increases.
EMF exist everywhere there is electricity.
EMF levels are higher closer to their source and decrease rapidly as the distance from the source increases. Their levels in the vicinity of electric lines are within the range of those encountered daily in home, offices, malls, casinos and other locations where there is electricity. The earth itself has a magnetic field of about 500 milligauss, while some medical diagnostic equipment have similar magnetic fields in the thousands. Normally, we speak of magnetic fields associated with the transmission or distribution systems and everyday use of electricity in terms of milligauss. Research has been conducted on EMF for more than two decades and several thousand papers have been published and reviewed by independent scientific experts.