Airport scanners present minimal risks
DEAR DOCTOR K:
I travel a lot for business. Every time I go through an airport security scanner, I wonder how it might be affecting my health. Are these scanners harmful? Should I avoid them?
There are currently two types of airport scanners in use. Some use non-ionizing radiation; the others use ionizing radiation. Most of the concern about scanners focuses on those that use ionizing radiation.
Ionizing radiation is the more dangerous kind and is definitely something to worry about. This type of radiation can damage your cells and can also affect a damaged cell's ability to repair itself.
Ionizing radiation can cause genetic changes that impair your cells' ability to control their own growth. If the cells start dividing when they shouldn't, a cancer starts. Lastly, ionizing radiation can damage the DNA in your sperm or eggs. This can cause mutations that could affect your future children. Exposure to very high levels of ionizing radiation can cause radiation poisoning and even death.
After reading this, you may well ask, "Why would I allow myself to be exposed to ionizing radiation?" My answer is, like most bad things, what matters is how much of it you're exposed to. So how much radiation is there in an airport scanner, compared to regular X-rays, for example?
It would take more than 50 scans at the airport to equal the radiation exposure from a single dental X-ray. And it would take 1,000 scans to equal the exposure from a chest X-ray. Suppose you made a back-and-forth trip by airplane once every month. At that rate, it would take you two years to accumulate as much radiation as you get from just one dental X-ray, and 40 years to accumulate as much radiation as from just one chest X-ray. Does that put it in perspective?
Here's another perspective. You actually can't avoid radiation exposure. Just living on Earth exposes us to low levels of ionizing radiation. There are radioactive substances in soil and cosmic rays from outer space.
And about those cosmic rays: When you're in an airplane, 30,000 feet above the Earth, you are exposed to more of them than on the ground. In fact, you are exposed to 100 times more radiation from traveling in an airplane than from the airport scanner. So if the scanner worries you, why are you flying in the first place?
My point is not that flying is dangerous. My family and I fly all the time. I'm just trying to put the risk of airport scanners in perspective.
So what should you do? I'll tell you what I do. I don't worry about airport scanners. I have a hip replacement, so I often set off the alarm. For that reason, I'm always disappointed when I arrive at an airport security area and don't see a scanner. I much prefer a scanner to a pat-down, in terms of my time and my dignity.
In a world full of things to worry about, airport scanners are not on my list.
(Dr. Komaroff is a physician and professor at Harvard Medical School. Go to his website to send questions and get additional information: www.AskDoctorK.com.)
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