Cigarettes contain radioactivity, because of the presence of Polonium 210 in the soil that it is grown in. This is verified by reliable studies and research, including former Surgeon General C. Everett Koop:

In 1990, then Surgeon General C. Everett Koop declared on national television that 90% of all smoking-related cancers were caused not by tar or any of the other factors we normally think of, but radioactivity.http://anthropik.com/2006/08/the-radioactive-ciggy/

http://www.acsa.net/HealthAlert/lungcancer.html

http://www.chiroweb.com/archives/10/24/24.html

http://en.wikipedia.org/wiki/Health_...obacco_smoking

This can lead to cancer, not just of the lungs, but the kidneys and other organs as well.