Radiation Dose Chart
We absorb radiation daily from different, very different, sources.About this, the numbers and scales in the graph below, taken from xkcd.com , are very interesting. However keep in mind that the risk of harm depends (but not only) on both the dose and the exposure time. From the chart: "the same number of sieverts absorbed in a shorter time will generally cause more damage, but your cumulative long term dose plays a big role in things like cancer risk." Note: the different color indicate the different scales ( muSv , mSv , Sv and "tens"(!!!) of Sv )