Answer to Question #1120 Submitted to "Ask the Experts"

The following question was answered by an expert in the appropriate field:

I work in a hospital archive where we have stored, in paper envelopes, around 100,000 x rays. I believe that each x ray might have some sort of "residual" radioactivity, although probably not even measurable. But if one puts together, in a poorly ventilated room, such material, what could the consequences be to an individual? Can this be dangerous and hazardous to a person's health? Most of the information that I have found on the Internet only relates to the radiation dose absorbed when actually taking the x ray.

There is a difference between x rays and radioactivity. Medical x rays are produced by an electronic machine and exist only for the brief period when the machine is energized. Once the machine is switched off, x rays cease to exist—in exactly the same fashion as a room goes dark when the light is switched off. X rays and visible light are parts of the same spectrum. The difference is wavelength. Radioactivity arises from two sources. Natural radioactivity is just that. It was produced in nature early in the earth's formation. Thus, it has always been with us and always will be. Artificial radioactivity is produced by bombarding atoms in a nuclear reactor or cyclotron. Therefore, there can be no residual radiation in x-ray films. There is no radiation risk. But how about dust, mold, etc. . . .

S. Julian Gibbs, DDS, PhD

Answer posted on August 14, 2001. The information and material posted on this Web site is intended as general reference information only. Specific facts and circumstances may alter the concepts and applications of materials and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice specific to whatever facts and circumstances are presented in any given situation. Answers are correct at the time they are posted on the Web site. Be advised that over time, some requirements could change, new data could be made available, or Internet links could change. For answers that have been posted for several months or longer, please check the current status of the posted information prior to using the responses for specific applications.