Here's an interesting theory: Researchers Örjan Hallberg of Hallberg Independent Research in Sweden and Ollie Johansson of The Karolinska Institute in Sweden theorize electromagnetic radiation from television and radio broadcast might be amplified by the metal components of the beds many of us sleep upon. Considering we spend a third of our lives sleeping (if not lounging around) ontop of these possible amplifiers, the unproven theory warrants further studies.
Scientific American reports the higher rate of certain type of cancers here in the United States, compared to other nations where futon or non-metal beds are used, may be connected to the construction of our beds:
Thus, as we sleep on our coil-spring mattresses, we are in effect sleeping on an antenna that amplifies the intensity of the broadcast FM/TV radiation. Asleep on these antennas, our bodies are exposed to the amplified electromagnetic radiation for a third of our life spans. As we slumber on a metal coil-spring mattress, a wave of electromagnetic radiation envelops our bodies so that the maximum strength of the field develops 75 centimeters above the mattress in the middle of our bodies. When sleeping on the right side, the body's left side will thereby be exposed to field strength about twice as strong as what the right side absorbs.
So the question may not be whether you should have a TV in the bedroom, but rather whether you should have a non-coiled mattress near your television. Would further scientific results supporting this theory sway you to switch from a coiled mattress to a futon or latex/memory foam bed, or move the television/radio from the bedroom?
More details about the study and theory over at Scientific American: Left-sided Cancer: Blame your bed and TV?