Submitted by Curious-Nothing6234 t3_z6ssvh in explainlikeimfive
If doctors have to shield themselves from the X-ray machine at hospitals after doing it once or twice a day, how do people sit in front of a constant X-ray when working for the airport?
Comments
pseudopad t1_iy324cy wrote
That's correct. The full body scanners use millimeterwave radiation that is non-ionizing (can't cause DNA damage) and barely gets deeper than your clothes.
The metal detectors don't use radiation at all, they use magnetic fields and detect changes in the field as metal passes through it.
Malkiot t1_iy4b2nw wrote
Technically magnetic fields are also radiation and both scanners / detectors use electromagnetic radiation, albeit of different frequencies.
Mand125 t1_iy4m4i5 wrote
They used to have some backscatter x-ray machines for full body scanning at some airports because federal contracting rules required two sources for scanners.
Since then they’ve been removed because any dose of x-rays is worth avoiding when you have the millimeter wave scanners available.
No-Comparison8472 t1_iy78vlw wrote
Health hazard of EMF radiation is not just a matter of frequency. A laser can burn through the skin yet its frequency is usually a million times lower than the GHz found in these millimeterwave chambers.
As_TheHoursPass t1_iy6hb8q wrote
The US did have full body x-ray machines post-911. The name for them was backscatter. They did cause increased cancer rates, because they were ionizing radiation.
The priority back then was on airplane safety. 911 did some really weird shit to American society, including authorizing a mass indefinite detention and torture system. Back then waterboarding was being debated in civil society as a humane way of extracting information.
Famous intellectual Christopher Hitchens infamously aligned himself with the rightwing neocons and thought that waterboarding wasn't torture and that it wasn't a big deal. He agreed to have himself waterboarded to put his beliefs to the test, and immediately after 1 waterboarding session lasting just seconds he flipped his mind and started calling it torture. He was one of the only people ever to to try it, and it must have changed at least some minds in broader society.
If you weren't around back then you wouldn't really understand. The country lost its marbles entirely. You'd think America was normal prior to Trump, but no it wasn't.
I don't know if they're still in service today, but it's always worth asking.
https://en.wikipedia.org/wiki/Backscatter_X-ray
Here's the video of Hitchens agreeing to being waterboarded.
nmxt t1_iy2zmn5 wrote
The machine in the airport only scans things inside it, it doesn’t leak X-rays outside. In hospital the entire room with the patient is the machine. The reason for this is that it’s not possible to remove a part of a human body, put it in the scanner and then put it back on the body. And full body X-rays would be excessive and unnecessarily dangerous. So they only shoot X-rays through the specific body part in interest while the patient is in the room.
ADDeviant-again t1_iy3s3vn wrote
BTW, doctors almost never use X-ray machines themselves, except some Cardiologists and Radiologists. It's almost always Radiologic Technologists doing the imaging.
The answer is that not all x-rays are created equal, and, not all RAYS are created equal. They have energies that vary widely. Microwaves, visible light, radio waves, UVA and UVB waves, x-rays, Gamma rays, etc. are all parts of the "electromagnetic spectrum" AND different types of these rays interact with matter differently. For instance, you can focus light through a magnifying glass, but not X-rays.
The issue here is that the airport scanners DO use a form of "radiation", but, not knowing how else to describe them, people say, "sort of like X-rays".
The scanners scanning the bags on trays use X-rays, and have protective shields. The body use a very specific energy of 30-300 GHz, capable of penetrating just a TINY thickness of matter before almost all essentially bounce off, though a few are absorbed on the very surface of the skin (just like heat and light can be) where the skin cells are already dead and can't be harmed. The imager counts on the ability of these mm-waves to get through most clothing, but then bounce off.
The one thing that is a good idea is closing your eyes, because the mm-waves won't penetrate your eyelids, but the very surface of your open eyeball is less protected.
[deleted] t1_iy2zo5a wrote
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MikuEmpowered t1_iy3oi96 wrote
Xray don't penetrate metal all that well.
In the hospital, they are shining an x-ray into you in an open space, not exactly contained, so medical workers need to shield themselves.
But at the airport, the xray is surrounded in a metallic box, effectively surrounded by shielding.
Aussie_Mo_Bro t1_iy2zkbm wrote
Unless you have certain underlying medical issues, occasional exposure is fine.
If you're taking an international you're being exposed to more radiation, anyway.
Doctors and nurses go behind a shield because it would be constant radiation over many years. This can and does cause health issues, not limited to cancer, but cancer is a big one
pseudopad t1_iy32irl wrote
That's correct, but OP wasn't talking about the danger to passengers who only pass by security a few times a month or year, they're talking about the operators who sit there all day long, 5 days a week, the whole year.
Target880 t1_iy3jto3 wrote
The devices that scan the luggage with X-rays are shielded so very little leaks out. They are large metal boxes with a scanner inside and the wall of them absorbs X- rays. The ray is also going in one direction, up or down so not toward where the baggage enters and exits.
The curtains the luggage passes through are rubber with lead in them and are X-ray shields. You have multiple of them per side if I am not mistaken.
So the number of X-Rays that leak out is minimal.
We do not use a small contained unit like that for humans because it would be quite impractical and not a great experience for the patient. We use larger protective boxes that fit humans and are not claustrophobic this is whole rooms
pseudopad t1_iy3opit wrote
I know, and OP got this answer already. I was just saying that the previous commenter was misunderstanding the original question.
TTTHD t1_iy310t1 wrote
If you are talking about the full body scanners that you stand in and raise your hands, those are not Xray. Only the things that scan bags are xray and they have shielding tunnels.