TSA security x-ray machines and our food?
11-13-2012, 07:15 AM
#11
Prime Minister/Moderator
Joined APC: Jan 2006
Position: Engines Turn Or People Swim
Posts: 40,389
Radiation and radioactive contamination are two different things...
Radiation is like light, it is emitted from a physical source. The source can be radioactive material, or a device which produces radiation. X-rays are produced by a device, but some medical radiation is produced by a physical source (which is handled carefully, accounted for, and kept heavily shielded).
Radioactive contamination is material which has become radioactive and now emits radiation. This is usually very low-level, but if the contamination gets inside your body it can do serious damage over a long period of time. Fallout from a nuclear weapon is what we usually think of here, although chernobyl dumped a lot as well.
Most radiation does not cause something it hits to become radioactive...this includes both particle (alpha, beta) and non-particle (gamma, x-ray) radiation. So any radiation you encounter in daily life is going to go in, do it's job, and go back out...it is not going to "activate" you or your food.
The exception is neutron radiation...this will cause almost any normal matter to become activated (buildings, dirt, food, even people). But the good news is neutron radiation is not used in our day-to-day lives...you would need to be directly exposed to a nuclear weapon detonation, an unshielded reactor core, or used reactor fuel to get any significant exposure. But if you did somehow get exposed to serious neutron radiation, then you personally would become radioactive...in addition to whatever damage the neutron exposure did, you would be slowly irradiating yourself from the inside out and might be hot enough that you would be a hazard to other people around you.
We all do get some neutron exposure from cosmic radiation, but not much you can do about that.
Radiation is like light, it is emitted from a physical source. The source can be radioactive material, or a device which produces radiation. X-rays are produced by a device, but some medical radiation is produced by a physical source (which is handled carefully, accounted for, and kept heavily shielded).
Radioactive contamination is material which has become radioactive and now emits radiation. This is usually very low-level, but if the contamination gets inside your body it can do serious damage over a long period of time. Fallout from a nuclear weapon is what we usually think of here, although chernobyl dumped a lot as well.
Most radiation does not cause something it hits to become radioactive...this includes both particle (alpha, beta) and non-particle (gamma, x-ray) radiation. So any radiation you encounter in daily life is going to go in, do it's job, and go back out...it is not going to "activate" you or your food.
The exception is neutron radiation...this will cause almost any normal matter to become activated (buildings, dirt, food, even people). But the good news is neutron radiation is not used in our day-to-day lives...you would need to be directly exposed to a nuclear weapon detonation, an unshielded reactor core, or used reactor fuel to get any significant exposure. But if you did somehow get exposed to serious neutron radiation, then you personally would become radioactive...in addition to whatever damage the neutron exposure did, you would be slowly irradiating yourself from the inside out and might be hot enough that you would be a hazard to other people around you.
We all do get some neutron exposure from cosmic radiation, but not much you can do about that.
