Looks like Benji pinned it.
I did want to point out that, as much as the other compounds in cigarettes get attention, nicotine itself is toxic to the point that it could cause irreparable damage to your cardiovascular system in much the same way other drugs like cocaine or heroin can. Toxicity relates to a compounds ability to create an unusual and unregulated physiological reaction, and the resulting narrowing of arteries and blood clotting certainly qualify.