OK, this is a rather inelegant way to put it, but it's on a lot of minds and has been for some time. Of course, it's not just cell phones; conceivably, any RF emission of sufficient duration and power could cause concern. And it's not just cancer, which seems to be the catch-all for our gross fear of illness. Indeed, the broader question is: Can radio make us sick and if so, how sick and under what circumstances?

Clearly, there are some situations where we absolutely know that RF is going to harm us. But this usually involves much higher power levels or longer-duration exposure than most people would ever experience. So, what about cell phones? Occasional use, low power, hmmm . . . shouldn't be a problem. Why can't we prove-given our long history of scientific investigation, our broad understanding of electromagnetics and the range of outstanding tools and techniques available today-that cell phones don't cause cancer?

Because, in the immortal words of Justice Clarence Thomas, you can't prove a negative. We need, therefore, to look for proof that cell phones are in any way harmful. And to date, despite numerous studies by engineers, scientists, physicians and public-health experts, there simply isn't any substantive evidence to make that case. Just about every study concludes with the statement that more study is indicated or required, perhaps because (let me be a little cynical here) more study is what such researchers do. Will we eventually find a connection between cell phone (or any other similar radio) usage and cancer (or any other human illness)? I really doubt it. But I'm certainly in favor of additional epidemiological studies. If a pattern emerges and a correlation can be established, I'd feel better with the knowledge in hand, and I'm sure you would as well.

The health question, I fear, will continue to haunt us. In the end, I'm willing to bet, we've nothing undue to fear. So when someone moves away as you fire up your phone for fear of "second-hand cellular," at least be comforted that they're not trying to eavesdrop on your conversation.

Craig J. Mathias is an Analyst with the Farpoint Group (Ashland, Mass.).