More on Radiation

So how is radiation in general defined?

• "anything emitted from a localized source" http://galileo.phys.virginia.edu/classes/304/rad_eff.pdf

This is a very broad explanation. I want to know what kind of radiation is emitted from a nuclear explosion. I also want to know how it affects living organisms, especially humans. I found this chart pretty interesting about the amount of radiation a person is exposed to in every-day life:

http://kansasmeadowlark.com/blog/2011/03/21/background-radiation-is-normal-in-overland-park/