The electronic cigarette was introduced to the U.S. market in 2007 and offers the nicotine-addicted an alternative to smoking tobacco. Most "e-cigs" are similar enough in appearance to be mistaken for regular cigarettes, but one look inside and you'll see the main difference: E-cigarettes don't contain tobacco. Instead, there's a mechanism that heats up liquid nicotine, which turns into a vapor that smokers inhale and exhale. Manufacturers and satisfied customers say that this nicotine vapor offers many advantages over traditional cigarette smoke. But regulatory agencies and some health experts aren't sure. They're asking questions about the possible side effects of inhaling nicotine vapor, as well as other health risks e-cigarettes may pose -- both to users and to the public. Those calling for tight regulations on e-cigarettes claim that these devices should be deemed illegal until the proper research trials have been conducted to prove that they're safe.
