What Is a Metal Mattress?

Components

• Mattress insulation, such as polyester fiber or compressed cotton, separates the metal coils from the cushioned surfaces and prevents the coils from poking through. Several layers of fabric wrap around the insulation. Consumers typically buy a mattress and box spring set because a box spring supports the mattress coils and lengthens the life of the mattress. The box spring also contains metal coils.

Coils

• Mattresses are available with different types of coils and various coil counts. The coil design, gauge of the wire used to make the coils and the engineering of the coil are more important in determining mattress quality than a high coil count is. A Bonnell coil, for instance, is widely used in lower-priced mattresses. This hourglass-shaped coil usually has five turns. More upscale coils include the offset coil, which is an improvement on the Bonnell coil, and continuous coil, in which each row of coils is made with a single wire.

Speculation

• According to a July 2011 article published in "Scientific American," a potential connection between these metal mattresses and certain types of cancer may exist. For reasons that are unclear, a higher percentage of people report sleeping on their right side more than their left. In the U.S., breast cancer and melanoma rates are higher on the left side than the right, but cancer rates in Japan do not have this discrepancy. The authors speculate that metal coil mattresses common in the United States, but not in Japan, may act as antennas for FM and television waves from nearby transmission towers, creating electromagnetic radiation that is strongest above the mattress, which is on the sleeper's left side.

Additional Options

• Although metal mattresses are the most preferred form in the western world, nonmetallic mattresses also are available. Different types of foam mattresses, such as memory foam, are gaining interest. Waterbeds, air beds and futons, which are flat padded mattresses common in Japan, are additional options.