Michael Siegel, an associate professor at the Boston University School of Public Health, talks about new U.S. government requirements for cigarette warning labels.   Images of a corpse and cancerous lungs are among nine graphic warnings that tobacco companies must start placing on cigarette packs sold in the U.S. next year. Siegel speaks with Carol Massar and Matt Miller on Bloomberg Television’s "Street Smart." (Siegel is a Bloomberg View columnist. The opinons are expressed are his own. Source: Bloomberg)