Let's get right to the answer: No one knows. We can't say whether cell phones, or any other consumer-grade wireless devices, are harmless. Indeed, we do know that certain forms of wireless radiation are quite the opposite. Spend a lot of time in the sun? The ultraviolet (UV) rays your skin is exposed to can cause cancer. We know that. Ditto for X-rays, gamma rays and cosmic rays, to which we are also exposed just by being on this planet.
Well, we also know that the only difference between the known harmful forms of radiation listed above and the microwaves that consumer products use is frequency. Microwaves have a lower frequency than the others listed, but both are forms of electromagnetic radiation. Does frequency (how fast the wave vibrates) make a difference?
Yes, it does. UV waves and the others mentioned above have very, very high frequencies -- hundreds of trillions of cycles per second (terahertz). Microwaves, on the other hand, are comparative slowpokes, with just a few billion cycles per second (gigahertz) at most. Microwaves are nonionizing radiation, while the others are ionizing. That's the important difference between the two.
Ionizing radiation has the necessary properties to cause changes at the atomic and molecular levels. That's what causes cancer with significant exposure. Of course, cancer has lots of other causes, including certain chemicals and one's genetic history. But can significant exposure to nonionizing radiation cause cancer?
We don't know. But the physicians and physicists I've consulted on this question don't think so. There are other related unanswered questions as well, such as whether the magnetic component of electromagnetic radiation can cause disease. Anyone who's ever had an MRI (magnetic resonance imaging) test has been exposed to one of the most powerful magnetic fields known, and I've heard nothing about such exposure being harmful in any way.
I've read an enormous amount on this subject, and I've concluded that consumer-grade wireless will not cause disease in most people. I have to allow that certain people might have a genetic proclivity to developing cancer or another illness from some amount of exposure, but I've never seen anything published on this topic.
What does get published is often sensational or is the result of poorly executed research featuring too many variables or too small a sample. One such study was reported in Computerworld. I see nothing in this report to be concerned about. One reason is the small sample size, while the need for a study to confirm these findings is another. Almost all studies have found no correlation between cell-phone use and brain tumors, and similarly, all of the high-profile lawsuits filed in this area have failed. It should be noted that the standard of proof in legal actions is far less than that in double-blind tests.
Still, the Food and Drug Administration is interested enough (as it should be) to commission yet more research (as it should do) as a result of the above report.
Indeed, we should study this issue and study, and study some more. One can never be too careful when health is concerned, but for now, my feelings are that our attitude should be one of prudence, not paranoia. If you don't have to spend all day on a cell phone, don't. Use sunscreen. Stay away from fat, sugar and cholesterol. You'll live to be 100 -- or, at least, it will seem that way!
As I noted last week , health-related safety is one issue that is unlikely to be settled anytime soon. What I'm looking for is large-scale evidence that a significant number of people are getting sick as a clear, direct result of exposure (including second-hand exposure) to the kinds of signals present in cell phones, wireless LANs and related devices and systems. With decades of wireless technology now under our belts, we should have seen something that correlates by now. I don't think we will, but we should keep trying.
There is, by the way, one very clear safety danger related to cell-phone use, and that's talking on the phone while driving. I'll cover that issue in an upcoming column.