Via xkcd comes this very informative chart on radiation exposure:
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click for ginormous graphic
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Sources:
http://www.nrc.gov/reading-rm/doc-collections/cfr/part020/
http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/tritium-radiation-fs.html
http://www.nema.ne.gov/technological/dose-limits.html
http://www.deq.idaho.gov/inl_oversight/radiation/dose_calculator.cfm
http://www.deq.idaho.gov/inl_oversight/radiation/radiation_guide.cfm
http://mitnse.com/
http://www.mext.go.jp/component/a_menu/other/detail/__icsFiles/afieldfile/2011/03/18/1303727_1716.pdf
http://blog.vornaskotti.com/2010/07/15/into-the-zone-chernobyl-pripyat/
http://dels-old.nas.edu/dels/rpt_briefs/rerf_final.pdf
http://en.wikipedia.org/wiki/Sievert
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Hat tip Flowing Data
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