Saturday, October 17, 2009

Protecting Yourself from Radiation

In the preceding post (Making Sense Out of Radioactivity ) I discussed the different types of radiation emitting particles and ray found in a nuclear explosion. Now that the terms radioactive decay, alpha and beta particles, and gamma rays have been defined I will discuss the ways to block each of these rays.

Alpha and Beta Particles:
You should not worry about sheilding these particles since there penetrating power is very low. Alpha particles are stopped by the skin or clothing. Beta particles penetrate up to 2mm on bare skin and may cause a sunburn if exposed for prolonged periods of time. These particles are not dangerous while they stay on the exterior of you body. Their danger exponentially increases when ingested though. This aspect has already been covered in the post (Is There Such a Thing as a Radiation Pill?).

Gamma Rays:
These are the most dangerous for of radiation decay out of the three listed above. Strict protective measures must be taken to protect yourself and your electronics from them.

It is important to understand that radioactive fallout (the sand and dust blown by a nuclear blast) radiates all three types of particles. Therefore the radiation is produced from where the particles are deposited, ex: Your house's roof.

Taking shelter in your basement:
The typical home offers very little protection against gamma rays as the material shielding you from the roof to the basement add up to a maximum of 2 feet of wood and insulation. However, it is much better than the protection attained from just standing outside of hiding in your car (worst idea). Try to be the farthest away from the walls and roof. Shut off all ventilation systems and windows. The trick to shielding gamma rays is to put as much weight as possible between you and the fallout particles. Use build an ''n'' shaped shelter using anything heavy. Doors, book, water filled containers, sand and salt bags, etc. Be very careful that your construction is solid enough not to collapse on you when your inside.

Taking Shelter in a Specifically Designed Fallout Shelter:
This is the best choice if you want to survive a nuclear attack. It doesn't cost a lot to build and doesn't require a lot of space. Since there is much to say on this subject, I will leave this to a future post.

Understanding Radioactive Decay and Half-Lives:
The term radioactive decay has already been explained in the post (Making Sense Out of Radioactivity), refer yourself to it if the term is still shady. The concept of half-lives is very important in choosing protective measures and the time you have to stay in your shelter. A half-life is the time it takes for the radiation level from a specific particle or ray (ex: Gamma Ray) to reduce its power by 1/2. This means that as time progresses the radiation levels will reduce exponentially. Ex: If a fallout particle generates 100RAD, when it finishes its first half-life it will be at 50, when it finishes its second half-life it will be at 25, and so on. Note that it will in time come closer to zero, but will mathematically never get there. However, at some point the radiation will be so weak that it won't affect humans or electronics. The duration of the half-life depends on the specif isotope used to fabricate the bomb. They have half-lives from a few seconds to a century. The shorter the half-life, the more intense the fallout radiation is in the beginning. There is no point in building a bomb with a half-life of a century since the country launching the attack would probably be destroyed themselves by the fallout carried in the wind. To conclude, the longer you stay in your shelter the less strong the radiation will be.

There are a couple of different types of devices available to measure radiation levels as well as exposure levels. The next post will address this topic.

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