Since most appliances are turned on briefly and then turned off, exposure to EMF is usually only for short periods of time. But power lines constantly produce magnetic fields. That is why most scientific research has looked at magnetic exposure from power lines, even though the magnetic field may be stronger around some appliances.
Electromagnetic fields (EMF) are invisible lines of force around electrical equipment, power cords and wires that carry electricity. EMF includes:
Electric fields are produced by voltage, such as when a hair dryer, coffee maker, fan or light plug is turned on. Increasing your distance from the source of the electric field will weaken the strength of the field. Electrical fields are also usually blocked or weakened by things that conduct (transmit) electricity, including trees, buildings and even human skin.
Magnetic fields are produced when current travels through wires or other electrical devices. For example, turning on a coffee maker creates a magnetic field. Like electric fields, increasing your distance from the source of the magnetic field weakens the strength of the field. Unlike electrical fields, magnetic fields pass through most materials, including trees, buildings and human skin.