Study: Smokers may tap into multiple sources for nicotine

LAURAN NEERGAARD, AP Medical Writer
FILE - In this Feb. 20, 2014, File photo, a patron exhales vapor from an e-cigarette at the Henley Vaporium in New York. The first peek at a major study of how Americans smoke suggests many use combinations of products, and often e-cigarettes are part of the mix. It's a preliminary finding, but it highlights some key questions as health officials assess electronic cigarettes. (AP Photo/Frank Franklin II, File)

WASHINGTON, D.C. — The first peek at a major study of how Americans smoke suggests many use combinations of products, and often e-cigarettes are part of the mix.