Via the XKCD web comic

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