ELECTROMAGNETIC FIELDS

The magnetic field depends upon the amount of current flowing through the wire regardless of whether the voltage is high or low. High voltage is used in power lines in order to pass more energy through a wire of minimum diameter, but it is the current that determines the magnetic field strength. As an example, Payne uses a high voltage power line 300 feet from a home and transmitting 300 amperes of current. This would result in a field in the home of about 7 milligauss.

Conversely, the low voltage wiring in the house itself, assuming 30 amperes on average 24 hours per day and wires averaging 10 feet from the occupants, exposes them to about 20 milligauss. During high exposure periods, such as working 5 feet from the wiring of a 40 ampere electric range, this rises to about 50 milligauss. All of these magnetic fields are small with respect to the earth's field. Also, even in a house near a high voltage transmission line, most of the exposure comes from the wiring of the house itself and it appliances.

Little is known about the biological effects of magnetic fields. Since these fields are weak in comparison with molecular forces, it is believed that the biological effects are small. If they are affected, however, biological systems must function in the usual environmental magnetic field. This field comes from the earth and, except in unusual locations, is not increased appreciably by human activities.