Answer to Question #6256 Submitted to "Ask the Experts"

First, I am sorry to hear of your recent diagnosis and wish you the best.

It is impossible to show that a person's risk of cancer is based on his/her radiation exposure from diagnostic x-ray exams. Cancer is a naturally occurring biological process, and it is estimated about 42 percent of the population will develop a cancer sometime in their lifetime. Even for the atomic bomb survivors who received significant doses of radiation, excess cancer deaths were not easily demonstrated below doses of 0.20 Sv or 20 rem of exposure. With regard to diagnostic x-ray exams, few result in high radiation exposure, as stated in this fact sheet. For example, it would take 5,000 chest (LAT) x ray exams, each of which result in a dose of 0.04 mSv or 0.000 04 Sv, to total 0.20 Sv. Again, an increase the risk of cancer is insignificant at this dose value.

It should also be noted that certain organs or tissues have a higher risk of developing cancer following significant radiation exposure. The prostate is not considered an organ that shows any risk of becoming cancerous following radiation exposure. Also, there is no test that relates radiation exposure to cancer risks at exposure values associated with diagnostic x-ray exams.

As for the question of future cancers, I would recommend discussing this issue with your physician or oncologist. I would not think x-ray exams would be a contributing factor as there is no significant relationship between diagnostic radiation doses and observed cancer effects.

John Jacobus, MS
Certified Health Physicist