Answer to Question #11404 Submitted to "Ask the Experts"

Category: Medical and Dental Patient Issues — Diagnostic X Ray and CT

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

Q

Last week I went for the first time to a podiatrist for an issue with my right toe. While I was waiting in a room to see the podiatrist, the door was ajar by about 10 centimeters (cm) and I could see that a patient was standing on a foot x-ray machine, about 2 or 3 meters (m) away from me. The podiatrist's aide took three x rays of that patient's foot. How much radiation did I absorb from scattered radiation? I am really concerned.

A

You absorbed virtually no radiation. Most of the radiation would be absorbed in the other patient's foot and the image receptor. A small fraction of 1% would scatter (bounce) in your direction, and at a distance of approximately 2 m or more the radiation would be even less. Radiation intensity drops with the square of the distance, so at approximately 2.5 m the radiation level is one sixty-fourth of what it is at 0.3 m. Your radiation exposure that day was more from radiation in the natural environment than from the three x rays you saw performed.

Kent Lambert, CHP

Ask the Experts is posting answers using only SI (the International System of Units) in accordance with international practice. To convert these to traditional units we have prepared a conversion table. You can also view a diagram to help put the radiation information presented in this question and answer in perspective. Explanations of radiation terms can be found here.
Answer posted on 26 December 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.