Adult Smoking in the US, Vital Signs, September 2011: “Tobacco use remains the single largest preventable cause of disease, disability, and death in the US. Some people who smoke every day are smoking fewer cigarettes; however, even occasional smoking causes harm. The percentage of American adults who smoke decreased from 20.9% in 2005 to 19.3% in 2010—about 3 million fewer smokers. But almost 1 in 5 adults still smoke. Reducing tobacco use is a winnable battle—a public health priority with known, effective actions for success.”