What exactly are EMFs? The basics.

EMF stands for electromagnetic field. Electromagnetic fields are comprised of an electric and a magnetic field perpendicular to each other, which travel together in an invisible wave form.

Where do EMFs come from?

1. Electric fields: These are the fields that emanate from anything that has voltage; basically anything electric, such as lamps, electrical wiring, outlets, extension cords, electrical appliances, and power outlets. 
2. Magnetic fields: The Environmental Protection Agency (EPA) has labeled magnetic fields a class 3 carcinogen. These fields can occur when there is an imbalance in the electrical wiring, and around electrical motors such as the motor in your refrigerator. A MAJOR source of magnetic fields is next to the main power meter for your house. You definitely want to avoid sleeping up against a wall that has a power meter on the outside. Electric clock radios can also generate magnetic fields. 
3. Power lines, whether above- or underground.
4. Metal plumbing: Yes, older metal plumbing can frequently carry a current.
5. Wireless communications: This includes wireless power meters (so-called SmartMeters), cell phones, cell towers, wireless routers, and cordless phones. Most of these types of technologies expose you to both electric- and magnetic fields.
6. The Latest Danger—'Smart Meters'Some areas of the United States have already begun installing a so-called 'smart grid,' where utility meters transmit data on your household energy usage wirelessly to the utility.