An individual’s magnetic field exposure varies throughout the day and depends on multiple factors including field levels in the home, vehicle, and work place as well as appliance use. Researchers from the Electric Power Research Institute (EPRI) surveyed 992 American homes in 1993 and found an all-room average magnetic field of 0.9 mG, though background field levels in some rooms exceeded 16 mG.

A follow-up EPRI study in 1998 characterized the 24-hour, personal magnetic field exposures of over 1000 people. An average 24-hour personal exposure of 1.25 mG was reported with a small number of people having average exposures over 10 mG.

Electric and magnetic fields (EMF) are invisible lines of force that are part of the natural and man-made environment. A natural source is the earth's magnetic field. Manmade sources include household or building wiring, electrical appliances and electric power transmission and distribution facilities. EMF strength decreases rapidly with distance from the source.

Electric fields are created around appliances and wires wherever a voltage exists, similar to the water pressure in a hose. Electric field strength is measured in units of volts per meter (V/m).

Health-related research around EMF focuses primarily on magnetic field exposures. Magnetic fields are created whenever electrical current flows, similar to the way water flows when the nozzle of a hose is opened. Magnetic field strength is measured in units of gauss (G) or more commonly in milligauss (mG).

It's easy to locate the source of an RTVI problem. Here's how:

Go to your main fuse box or circuit breaker panel with a battery-operated AM radio tuned between stations. Listen for interference on the radio. (Be sure to bring a flashlight if the box or panel is located in a dark or enclosed area.) 

When you hear the interference that has been bothering you, interrupt the power to your home by turning off the MAIN circuit breaker. (Do not remove fuses and leave their holders exposed.) 

TIP: For instructions on safely turning your circuit breaker off and on. 

If you no longer hear the interference on your radio, the source of the interference is in your home. If you continue to hear the interference, the source of the noise could be in a neighboring home or building. Restore the main breaker and all other sub-breakers to "on." For further assistance locating the source of the interference, please call SCE at 1-800-655-4555.

If the interference stopped when you shut off the main circuit breaker, try to locate the source of the interference in your home. With your AM radio tuned between stations, turn the MAIN circuit breaker back on. After the interference returns, turn the circuit breakers off one at a time until the noise stops. Now turn on all the breakers except the one that stopped the noise.

Because the source of the interference is on the circuit you turned off, check your house for the outlet, doorbell, light, clock, or other appliance or piece of electrical equipment without power.

Congratulations! Once you've located and removed the interfering device, your radio and television reception will return to normal.

Most interference is caused by household equipment or a neighbor's appliances and tests in most areas have shown little or no interference from Southern California Edison company lines. If your appliances are causing the RTVI, they may be affecting your neighbors' radios and televisions as well. 

RTVI may be caused by common household appliances including heating pads, a faulty door bell transformer, tropical fish tank heaters and pumps, baby wipe warmers, touch lamps, dimmer switches, and home lighting photocell switches.

If your trees have grown into or near power lines, pruning requires the expertise of a qualified line-clearance arborist. To report trees growing into or near power lines, call us at 1-800-655-4555 or submit a Tree Trimming Request online.

Report a Streetlight Outage online or call us at 1-800-611-1911. 

It's important to be prepared. A good place to start is creating a supply kit.

If you have doubts about the safety of any electrical item, do not use it. We will inspect our equipment when you report a problem like flickering lights.

The best way to put out an electrical fire is with a fire extinguisher. If you don’t have one, remember these tips.

Your first step is to call 911 and inform the operator that it’s an electrical emergency. Don’t touch anything or anybody that’s come in contact with energized equipment, and keep others away too. If the person is free from the electricity source and not touching it at all, administer first aid including CPR if needed. Be sure medical help is sought immediately, because electrical burns may not be visible. Learn more about safety around electricity.