Answer to Question #10084 Submitted to "Ask the Experts"

Category: Security Screening

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

Q

Many x-ray scanning systems for passenger-occupied vehicles and cars are in use. What is the average radiation dose per scan from these scanners? What is the risk of cancer due to these scans? Is it justified to use these scanners to secure high-profile buildings?

A

The average radiation dose per scan to a person sitting in a vehicle that passes through one of the vehicle scanners would be about 0.05 µSv per scan. This is far below the level of radiation exposure that is known to cause cancer or any other health effect. The 0.05 µSv per scan is about 1/100,000th of the radiation dose that individuals receive each year from background radiation exposure.

As for the justification for this use, the Health Physics Society (HPS) has a position statement on the topic of using ionizing radiation on humans for security screening and believes that it is a justified practice if certain criteria are met. You can read that position statement on the HPS website.

Kelly Classic
Certified Medical Health Physicist

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 9 February 2012. 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.