Nearly two-thirds of the people on Earth now use mobile telephones, according to a study by the International Telecommunications Union. But how safe are those phones? Scientists still aren't sure, but some evidence is starting to suggest there may be danger along with the convenience.
They go by various names — cellular telephone, cell phone, mobile, wireless, handy — and an estimated four billion people use them worldwide.
Each of those phones has a tiny radio transmitter to communicate with the wired telephone network, and for years, scientists have been trying to determine whether those RF, for radio frequency, transmissions might be harmful.
A U.S. Senate subcommittee this week brought together some experts to review the evidence and focus on whether more research is needed.
Not too long ago mobile phones were exotic and expensive, even seemed magical. Now, as subcommittee chairman Tom Harkin noted, we take them for granted.
"I would venture to guess that almost everyone in this room uses a cell phone on a regular basis, and most of us don't give a second's thought that it could harm us in any way," said the Iowa Democrat.
Measuring that harm is difficult. One problem is that mobile phones have been in widespread use for a relatively short per