Answer to Question #12526 Submitted to "Ask the Experts"

Category: Pregnancy and Radiation — Exposures to embryo/fetus

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

Q

My wife and I have to go through a vehicle scanner at our place of work. My wife is pregnant with our first child and I am worried about any potential harmful effect the radiation might have on my wife and the fetus. There is a lot of material about airport scanners on this website, but very little information about vehicle scanners. Kindly let us know if we need to worry or if there is anything we can do to avoid possible health risks. My second question is about possible human errors with these scanners. Are these devices equipped to handle any possible mistakes from the operator using the machine, e.g., an untrained operator using a higher radiation dosage that can be potentially harmful for passengers?

A

This is an excellent question. In short, there should be no additional risk of harmful effects for the fetus with a properly operating vehicle scanner. 

I am going to use radiation dose information from another Ask The Experts answer 11239 so you can also take a look at that answer if you'd like.

I tried to find Saudi Arabia radiation regulations and did; however, they were in Arabic so I will be relating the radiation doses from the vehicle scanner to radiation dose limits in practice in the United States.

As you can see in answer 11239, the radiation dose to a person in a vehicle going through a vehicle scanner is approximately 0.05 microsievert (uSv, a unit of effective radiation dose). To share why I believe there would be no additional risk of harmful effects, let me offer some dose comparisons.

Vehicle scanner = 36 uSv y-1 (0.05 uSv scan-1 or for coming and going in one day 0.1 uSv day-1 so about 36 uSv year-1).

United States background radiation = 3,000 uSv year-1.

United States radiation limit for a member of the general public = 1,000 uSv year-1.

United States radiation limit for pregnant worker exposed at work = 5,000 uSv year-1.

Lowest radiation dose shown to cause harmful fetal effects = 60,000 uSv at one time.

The radiation dose from your daily travel through a vehicle scanner is very small compared to natural background radiation (that we each receive from various environmental sources) and well below radiation dose levels shown to cause harmful effects. Of course, your actual radiation dose might vary depending on the speed of the scan and the parameters used to perform the scan (x-ray energy, etc.), but it is highly unlikely the fetal dose would even approach any of the other radiation doses I've listed.

As to your question about operator error, I do not know if the equipment itself could detect an error, but there are emergency off buttons if an error is detected by an operator. 

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 6 July 2018. 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.