Official statement from my MD after consulting a radiological medicine specialist about backscatter X-ray scanners and my … um … “previous exposure”:
“Next time you travel, we’d like you to carry a dosimeter and record daily exposure both on days you travel and days you don’t. A single trip’s exposure probably won’t make much of a difference, but it would be nice to establish a baseline so we can monitor your total exposure.”
While I appreciate my doctor’s ability to make decisions based solely on evidence, this does not make me feel more comfortable. Now I have to fire off a letter to the TSA and find out if I’m going to be able to carry an X-ray dosimeter through a backscatter checkpoint, under the guises of a “medically necessary device.”
OK, that’s a new one. Just how sensitive to radiation are you? A yearly chest x-ray is generally considered a negligible amount of radiation. I have never heard of anyone outside the nuclear energy profession having to worry about day-to-day exposure. that they have to worry about getting nuked at the airport. Given the increased amount of ionizing radiation one is exposed to at flight altitude (especially now that we’re heading toward solar maximum again), might a red-eye flight be advisable?
Normally at this point I’d slip in a witty remark about apprising your dr. of any new symptoms such as the ability to climb walls, shooting webbing from your hands, or a predilection for red and blue unitards. All kidding aside, I hope this is not adding yet one more health concern to your list.
Long story, but we’ll just call it an “industrial accident” resulted in me receiving a single dose of around 700 mSv. The OSHA limit for X and gamma radiation in one’s lifetime is 400 mSv, so there is legitimate cause for concern.
I see your point. According to what I’ve been able to dig up, a typical backscatter X-ray exposure is about 0.02-0.025 mSv, so unless you do an awful lot of flying you’re not likely to exceed the background dosage (~3-4 mSv/year). At least, wearing a dosimeter would allow you to confirm one way or the other the 20 microsievert claim.
If you’re worried about protecting the family jewels you could always wear Flying Pasties 🙂
Check it out. http://www.flyingpasties.com. You’re welcome.
My concern (and my doctor agrees that I’m not being hysterical here) is the way these machines are designed. They are open on the sides, and there is absolutely no protection provided for people waiting in the queue.
Yes, I know inverse square law and all that means that the people waiting in line will likely receive background levels of radiation. However, I have serious concerns about the maintenance of these machines.
Luggage X-ray scanners have been notorious for their poor maintenance over the years and leaking not insignificant amounts of X-ray radiation. Unlike X-ray machines in hospitals, these machines are not routinely inspected and maintained with any precision. They are also operated by .. well, to be frank, idiots. X-ray machines in hospitals receive regular basic maintenance and are operated by people with a basic understanding of biology, physics, and the reaction between the two. Even a beginning radiologist knows enough about X-rays to understand the implications of a poorly functioning machine.
Frankly, I have no confidence that the machines are actually only emitting 25 uSv. As my own experience demonstrates, it is real easy to have an X-ray emitter “screw up” and emit more than it is supposed to. And even at the microsievert level there is little that can stop a wayward X-ray photon.
EDIT and a side note: Every hospital radiology department I’ve ever seen has employees wearing dosimeters. I’ve never seen a dosimeter on any X-ray operator at an airport or public building. If one of these machines was malfunctioning, who’d know?
A number of years ago I read of an incident in which an x-ray machine at a hospital in Denver gave potentially hundreds of patients excessive dosages of radiation. Turns out the manufacturer failed to account for Denver’s mile-high altitude and calibrated it for near sea-level atmospheric pressure. So apparently, at the end of the day we’re all potentially one company physical away from eating lunch at the atomic cafe.
Seriously, given the maintenance issues you mention, there _should_ be a study of airport x-ray machines (NOT done by the TSA) to see just how much radiation people are being exposed to. Question is, would the Gummint allow it?