For an overview of radiation’s relation to cancer, see:
http://www.cancer.org/cancer/cancercauses/othercarcinogens/medicaltreatments/radiation-exposure-and-cancer

http://hss.energy.gov/HealthSafety/ohre/roadmap/achre/intro_9_5.html

For new thinking on the role of “junk” DNA in cancer, see:
http://www.nytimes.com/2012/09/06/science/far-from-junk-dna-dark-matter-proves-crucial-to-health.html

For the effects of low-dose radiation, go to:
http://www.nap.edu/openbook.php?record_id=11340&pag