03-17-2011, 09:03 AM
It's well known that iodine protects you from radiation. As do tinfoil hats. 8-)
The reason you want to take iodine tablets is to make sure your body is "full" of "normal" iodine. This prevents/limits the bodies uptake of the radioactive iodine isotopes. This is only necessary in the event of a large fuel failure that is released to the environment.
It is not something that will protect you from radiation in general, like a lead suit.
More info:
http://mitnse.com/
The reason you want to take iodine tablets is to make sure your body is "full" of "normal" iodine. This prevents/limits the bodies uptake of the radioactive iodine isotopes. This is only necessary in the event of a large fuel failure that is released to the environment.
It is not something that will protect you from radiation in general, like a lead suit.
More info:
http://mitnse.com/
MIT wrote:
Radiation released from reactors at Fukushima and what it means
The radioactive fission products from the affected reactors include noble gases (xenon and krypton), volatile radioactive isotopes (iodine-131 and cesium-137) and non-volatile fission products. As mentioned before, these radioactive products release radiation as they decay. Therefore, over exposure and/or contact with them is dangerous. The noble gases are usually not of a big concern since they are inert, and tend to impose very small doses. Non-volatile fission products usually stay within the fuels so that is not much of a concern to the general public either. The fission products of most concern are the volatile ones such as I-131 and Cs-137 since they can be dispersed in air and get carried far away by wind from the affected reactors.
Iodine-131 is a radioactive isotope that releases beta particles (electrons). Concentration of iodine-131 in the thyroid has been shown to cause thyroid cancer. Therefore, it is a big concern if too much iodine-131 gets out of the reactor and falls to the ground away from the affected reactors. This can contaminate food, water, and animal products such as milk. The Japanese government has distributed iodine pills to people in the affected area. These iodine pills contain stable iodine-127, which does not cause cancer. When people take these iodine pills their bodies absorb the stable iodine to a level that prevents or limits the absorption of I-131, which helps to prevent the risk of thyroid cancer. Another fact about radioactive iodine-131 is that its half-life (the time it take for half of it to decay to stability) is only about 8 days. This means that after about three months, almost all of the radioactive iodine-131 would have decayed away.
Cs-137, also emits a beta particle as it decays. Exposure to Cs-137 can also increase the risk of getting cancer but that again depends on the dose and the dose rate. However, Cs-137 causes a much longer term contamination problem because its half-life is about 30 years. Depending on the amount of Cs-137 that is released, and the regulations for acceptable elevated background radiation levels, the area contaminated with Cs-137 may not be inhabitable for a long time.