Relax--radiation is good for you

November 27, 2002

By Greg Freiherr, Editor, gfreiherr@cmp.comRadiation might not be all that bad. Don't take my word for it. Look at the paper written by University of Pittsburgh physicist

By Greg Freiherr, Editor,

Radiation might not be all that bad. Don't take my word for it. Look at the paper written by University of Pittsburgh physicist Bernard Cohen, Ph.D., in this month's American Journal of Roentgenology.

I don't pretend to understand the analyses Cohen cites to support his contentions, much less follow the line charts of lung cancer mortality versus mean radon level, with their first and third quartile intersections with the linear no-threshold theory. A lot of this relies on statistics, and despite anyone's best efforts, statistics can be misleading. (I was told recently that 47.2% of all statistics are made up, but I have no proof of this.)

I am, however, a fan of hormesis, which states that low-level radiation not only is harmless but that it might actually be helpful. It helps, Cohen said, at least in some cases, by stimulating the immune system to attack cancer. I like this idea, if for no other reason than cognitive dissonance.

Radiation exposure is inescapable. And I, for one, would feel better if I had reason to believe it doesn't have a cumulative effect leading inevitably to my death. Hormesis goes a long way toward that end. I like to think we may only be scratching the surface of the good news hormesis might bring us. If it can fight cancer, who's to say radiation doesn't have some positive effect on immune systems fighting coughs due to colds?

It's worth noting that Dr. Cohen's conclusions about radiation are not entirely of his own making. The article published in AJR is a review--or more exactly a meta-analysis--of previously published, peer-reviewed data. For the most part, these data have been shunted to the backwaters of scientific discussion, thereby allowing the continued prominence of the linear no-threshold theory, which states that any level of radiation exposure, no matter how small, increases the chance of developing cancer.

This has served as grounds for well-intentioned but misguided pundits to attack the use of x-ray-based imaging equipment for everything from mammography screening to the more controversial "wellness" CT screenings. It's made me question the wisdom of going along with head x-rays on my children when sinus infection is suspected and dental x-rays to find out why those adult teeth haven't come in yet.

In this way, our preoccupation with radiation can itself be harmful. And, while I'm certainly not going to say no to the hygienist the next time she drapes that lead apron over me, I'm going to feel a little bit better.