Urea, a chemical compound that is a major component in urine, is used to add "flavor" to cigarettes.

The United States is the only major cigarette market in the world in which the percentage of women smoking cigarettes (22%) comes close to the number of men who smoke (35%). Europe has a slightly larger gap (46% of men smoke, 26% of women smoke), while most other regions have few women smokers. The stats: Africa (29% of men smoke, 4% of women smoke); Southeast Asia (44% of men, 4% of women), Western Pacific (60% of men, 8% of women).

The U.S. states with the highest percentage of smokers are Kentucky (28.7%), Indiana (27.3%), and Tennessee (26.8%), while the states with the fewest are Utah (11.5%), California (15.2%), and Connecticut (16.5%).

The nicotine content in several major brands is reportedly on the rise. Harvard University and the Massachusetts Health Department revealed that between 1997 and 2005, the amount of nicotine in Camel, Newport and Doral cigarettes may have increased by as much as 11 percent.

Smoke 10 or fewer cigarettes a day and your risk of dysfunciton is 16% greater than non-smokers; 11 - 20 cigarettes a day has been linked to a 36% rise in erectile problems; and men who smoked more than 20 cigarettes a day have a 60% greater chance of dysfunction.

In 1970, President Nixon signed the law that placed warning labels on cigarettes and banned television advertisements for cigarettes. The last date that cigarette ads would have been permitted on TV was extended a day, from December 31, 1970 to January 1, 1971 to allow the television networks one last cash windfall from cigarette advertising in New Year's Day football games.

At a global take of more than $400 billion, it's one of the world's most largest industries.

Just 4 cigarette brands -- including the popluar American brands Marlboro, Kool and Kent -- own roughly 70% of the global cigarette market.