Grim reports about the Fukushima nuclear plant continue every day. The media are now reporting that radiation from the plant has been detected in "miniscule" amounts across the US. They don't define miniscule, apparently merely quoting some government source. But every so often, they trot out some "expert" who warns us that there is no safe dose of ionizing radiation, that any additional quantity leads to additional deaths from cancer.
To put all this ominous news into perspective, I suggest that you take a look at xkcd's radiation dose chart (click the image to see it full-size). It elegantly illustrates the relationships across a broad range of radiation exposures, from sleeping next to someone or holding a banana to standing beside the molten core of a reactor. I think Edward Tufte would approve.
After spending some time studying the chart, I wondered if the "no safe dose" advocates always sleep alone, never eat (or even stand near) bananas, never go into buildings containing granite or marble, never fly on airplanes, and live only at sea level. Somehow, I doubt it. But how sad for them if they do.
I'm going to remain in Colorado, where I get lots of extra ionizing radiation due to the altitude. But somehow, people still manage to live longer.