Scientists begin investigating possible health impacts of e-cigarettes

A study released in January found that e-cigarette vapor can promote the development of cancer in certain types of human cells — at least, when those cells are in a petri dish. These are early findings, and they don't yet undermine the idea that e-cigs are healthier to smoke than regular cigarettes. But they do prompt some questions about second-hand smoke and the health of people you smoke e-cigarettes around.