Some people say that nothing beats the soothing warmth of a tiled bathroom floor heated by an electric radiant heating system. The concept is simple -- when you're building a new bathroom or renovating an existing one, you lay an electric heating mat on the subfloor and tile over it. The plastic mat, made of heat-resistant polyethylene, contains looped resistance wire that carries an electrical charge, transferring heat to anything it touches. In this case, the heat warms the floor and, over the course of an hour, the rest of the room. It's like an electric blanket without the fabric. But you've probably been told that it's bad for you to sleep under an electric blanket while it's turned on. If that can have ill health effects, then you'd think that the radiant floor system would, too.
Concerns about electric blankets are because of electromagnetic fields (EMF) they emit. Anything that runs on electricity has an EMF -- your microwave oven, clock radio, floor lamp, hair dryer and yes, your radiant floor heating (RFH) system. Before we get to whether or not there's any danger of you getting cancer from your warmed floor, we need to learn a little bit about an EMF.
Every alternating electric current (AC) creates both magnetic and electric fields. Together, they're known as an EMF. The electric field is proportional to the voltage, which moves electricity through the wires. The magnetic field is proportional to the current -- which is the amount of electricity. The EMF is emitted from both the device and the wire carrying the current to the device.
High amounts of EMF are emitted from transmission power lines, also known as high-tension wires, and transformers. Transformers are the small black or grey cylinders on power poles that take massive amounts of electricity from the lines and reduce it to a safe level for your home. Underground power lines use larger green boxes you've probably seen at street level. Some studies show that children living too close to high tension wires have an increased chance of contracting leukemia and other types of cancer [source: DeNoon]. While there isn't definitive proof, most experts agree that you should try to avoid prolonged exposure to high doses of EMF.
So if clock radios and electric razors emit an EMF, can they potentially be hazardous to your health? Or could your electric radiant floor heating system lead to cancer? We'll get to the bottom of these questions on the following page.