As long as the situation at the Fukushima power plant remains out of control, people are going to keep on being worried about radiation exposure. Even though we're exposed to a fair amount of radiation in our daily lives (like every time you eat a banana), everyone is pretty naive about where radiation comes from and what it can do.
Hence the plethora of radiation dosage graphics. We already posted an excellent one, but here is a second, more artful piece, by David McCandless at Information Is Beautiful. It shows the progression from tiny bits of safe radiation to more dangerous levels:
[Click to enlarge]
Here's the really safe stuff, which includes every day activities from those bananas (they contain radioactive potassium) to cross-country flights (when you're much closer to the sun).
The graphic notes that you're getting about 3.5 microsieverts if you spend a day near Fukushima. And the worst levels of current measurement by the Energy Department show the surrounding area getting hit by about 22 microsieverts, just about double what happens on your average day. There are, of course, places in the water around the plant that are much higher. At that level, things can start getting really bad:
As you can see, things start getting very dangerous very quickly in the 1,000 microsievert range, ranging from extreme temporary sickness and increased risk of cancer to fatal doses. Luckily, even the workers inside Fukushima haven't reached those levels yet (that we know). Let's hope everything is under control before they do.