Answer to Question #11276 Submitted to "Ask the Experts"

Category: Radiation Effects

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


In our department, there is a room which was used as the location of an internet switchboard for many years. Now, to get a spare office room and to locate one academician into that room, they are changing the place of that switchboard. I am wondering, even if the switchboard is taken out of that room, will the harmful effects of it continue? Since the switchboard emitted radiation to the walls of that room for many years and the walls absorbed it, do you think it is dangerous to stay in that room to work?


The simple answer is no. An internet switchboard cannot make the room radioactive.

The low-energy electromagnetic (EM) radiation from a switchboard could be heat (invisible infrared radiation), light from on/off indicators, or radio waves, depending upon the manufacturer of the switchboard. These lower-energy radiations and even higher-energy x rays, used in a doctor's or dentist's office, do not make anything radioactive. They all work just like a lightbulb in a dark room. When the light is switched off, the room becomes instantly dark. This is because there is no transformation in the nucleus of the atoms in the wall's material. You have to transform the nucleus of an atom to make it radioactive. To do this it takes much, much more energy than any lower-energy radiation or EM waves and even high-energy x rays used in medical diagnostics.

There is more information on why lower-energy EM waves (microwaves) and x rays do not make anything radioactive. See:

Microwave Oven Question and Answer (Q&A)—"Heat imparted to any article from a microwave oven is no different than heat from any other source. There is no lasting or special effect of the microwaves other than the effect of the heat."

Question 10114—"X rays are only present in the room during the period of time that the x-ray unit is energized, to produce x rays . . . As soon as the exposure is complete, there is no more radiation present in the x-ray machine, the room, or any surrounding areas."

John P. Hageman, MS, CHP
Radiation Safety Officer, Principal Scientist

Answer posted on 27 July 2015. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, 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. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.