Answer to Question #12526 Submitted to "Ask the Experts"
The following question was answered by an expert in the appropriate field:
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?
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).
U.S. background radiation = 3,000 uSv year-1.
U.S. radiation limit for a member of the general public = 1,000 uSv uSv year-1.
U.S. 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.
Certified Medical Health Physicist