Electromagnetic radiation, that's what. Even prehistoric man was exposed to the earth's natural magnetic field. But the dawn of the Industrial Age brought hundreds of new sources of electromagnetic radiation into our homes. And therein lies the problem.
Electromagnetic radiation is produced in frequencies that range from high to extremely low.
High frequency waves, such as X-rays, have long been associated with health problems given sufficient doses and exposures. But middle frequency waves, such as microwaves, and low frequency waves, such as television waves, have not been shown to be harmful. Hundreds of public and private studies on the health risks of ELF waves have yielded conflicting results. These health risks sound ominous, but most scientists do not yet believe there is cause for great concern. For childhood leukemia, which affects one in 14,000 children per year, ELF exposure may raise the risk to two children in 14,000.