The Sum of All Fears

I know that many of you pay attention to what's going on in the world, who doesn't? In light of recent events, and my perception that many people, through no fault of their own, have very little understanding of radiation and radioactivity in general, I have decided to write these two short articles to try to decrease the level of FUD (Fear Uncertainty and Doubt). The subject that I am commenting about is the recent dual tragedy of earthquake/tsunami and the resultant nuclear facility problems that have been plastered all over the news. You have probably heard of the "plutonium leak" near Fukushima and that there have been increased levels of radiation found in the rainwater in Boston, I am going to try to alleviate any fears that you might have about these two events. First the rain water in Boston. The amount of radioactivity that was detected in the rainwater in Boston was 71pico-Curies. For those who don't know what a Curie is, have no fear, a Curie is defined as 37000000000 (37 Billion) radio active decays per second. The unit prefix PICO is defined as the quoted number (in this case 71) multiplied by 0.000000000001. Now for the math bit which makes this relevant, multiplying both numbers together we get a number that in essence means that they were detecting about 2.6 radioactive decays per second. If this sounds like a lot, for comparison, the smoke alarm currently in your house has 30600 decays per second. Additionally the radioactive substance detected in Boston is Iodine131. Iodine131 has a half life of 8 days. This means that half the iodine is gone after 8 days, so in 4 weeks the amount left will be a little over 1/20 of what was originally detected.

Now for Fukushima. There was a reported plutonium leakage found in the soil surrounding the reactor. The amount of plutonium that was found in the soil was very small; in fact it would not normally have caused any concern whatsoever since the amount that was found was in no way more or less than what was scattered around the globe when the US and Russia were testing our nuclear weapons. The only reason that they know that this material came from Fukushima is because of the specific isotope (or atomic variation if you don't know that an isotope is) was specific to the Fukushima reactors. I would like to stress that they did not measure any radioactivity appreciably above the normal levels that are usually found in soil anywhere in the world.

As I am sure that this is not the last of the news that will come from Japan, there will most likely be follow-up posts.