This radiation infographic is too small to read. There's a reason for that. Technically, it's because we constrain images to 600 pixels wide. Stylistically, it's because we'd like to point out that all things are relative. Head on over to XKCD to see just how much ionizing radiation you're likely to be exposed to performing radioactive activities (or just sitting still) and how that compares to the amount that researchers presently believe is capable of having an ill effect. Then, decide whether you should enlarge or reduce the size of your tinfoil hat accordingly.
[Thanks to everyone who sent this in]