"Don't Panic." (The first sentence in the Hitch Hiker's Guide to the Galaxy, by Douglas Adams)
What is the primary object of television, radio, and newspapers? If you answered, delivering accurate news, you would be wrong. Their primary object is to sell advertising. To earn the most money selling advertising, you need to attract the largest possible audience. Delivering thoughtful accurate news is one way to attract an audience. But in the news business they say, "If it bleeds, it leads." Do you want to guess why? Crisis and hysteria attract an audience.
Potassium Iodide tablets are flying off the shelves here in the good ole' U.S. of A. People are buying them to protect themselves from certain lingering and painful death caused by the radiation escaping from the damaged Japanese nuclear power complex. After all, this is a catastrophic disaster of unfathomable proportions.
There is just one problem. Iodine is toxic and it doesn't take much to make you sick or a whole lot to kill you. (!!!???)
It is true that your thyroid gland needs a small amount of iodine for good health. Without it, you could not function properly. But while a small amount is necessary, like the amount added to table salt, it doesn't take much to be deadly poison. If you are not a salt eater, eating seafood, particularly deep-water fish like tuna, will provide you with more than enough iodine for good health.
So what's with the Potassium Iodide tablets? Of all of the radioactive particles that can be released from a nuclear accident, a radioactive form of iodine is the only isotope you can protect yourself from by making sure your thyroid gland is stocked up on iodine so your body will resist absorbing any additional iodine you may come into contact with. But iodine is a pretty heavy particle and any radioactive iodine that escapes from the accident site isn't likely to travel more than a handful of miles. Potassium Iodide tablets won't do anything for any other radioactive particles.
I am not a scientist or an engineer, but I have been listening to people who are. The reporting on the Japanese nuclear power plant complex does not match the reality.
How many people died from the American Three Mile Island accident? The answer: zero. Not only that, a study 25 years later shows that there is no increase in cancer rates or deaths as a result of the accident. How many have died in Japan from radiation? None. It is doubtful that there will be any lasting impact.
The Japanese nuclear reactors automatically shut down when the earthquake hit. All of the containment vessels for all of the reactors survived both the earthquake and the subsequent tsunami. They exceeded their design parameters. The problem is with the spent fuel rods. Without circulating coolant, they over heat, evaporate their cooling ponds, and can begin to melt down. That is what is going on.
The genesis of the anti nuclear movement was the anti war crowd. Electric power generation can be an excellent byproduct in the "manufacturing" process of U235 and Plutonium for nuclear weapons. That is exactly what the Chernobyl nuclear complex was; a nuclear weapons fuel supply made with Soviet quality design, Soviet quality engineering, and Soviet quality construction techniques.
At the end of World War II, the Japanese were forced to adopt a constitution that all but prohibits them from having an army, navy, or air force. Spent nuclear fuel rods can be reprocessed into new fuel rods over and over until there is nothing left but inert "ash." Reprocessing fuel rods is also how you could collect bomb material. Under President Jimmy Carter, the U.S. prohibited itself from reprocessing nuclear fuel to show the Soviets that we really meant them no harm. That precipitated our "nuclear waste problem." The Japanese also decline to reprocess their spent fuel. If the fuel rods had been reprocessed, there would be no potential meltdown today (and the U.S. wouldn't have a nuclear waste storage problem).
Everyone is continually exposed to radiation. Sunlight is radioactive. The Earth is radioactive. Every smoke alarm in your home has radioactive materials in it to make the detector detect. Even your television (non flat screen type) emits radiation.
It is worth noting that there are four nuclear power plants in California and one in Washington State. Although these areas are prone to earthquakes, the locations of these plants are not capable of being hit by a tsunami. It was not the 9.0 earthquake that caused the nuclear problem in Japan, but the tsunami.
Several years ago, the New York Times covered a study of Chernobyl, Hiroshima, and Nagasaki and were shocked to discover that people living in areas with elevated radiation enjoyed better health and had less cancer than the general population. (The reason is not known.)
The earthquake and tsunami have killed more than 15,000 people. It is not likely that even one person will die from the nuclear power plant. A little perspective may be in order.