"What’s in All That E-Cig Vapor?"

"Wander into a vape shop in the mall or online, and you can find a smorgasbord of flavors: cotton candy, vanilla custard, even Unicorn Milk or Katy Perry’s Cherry.

Flashy flavors have helped e-cigarettes, designed to vaporize a nicotine solution, grow into an industry with an estimated $3.5 billion in annual U.S. sales. Less than a decade after the battery-powered devices were introduced in the United States, an estimated 10 percent of American adults and 13 percent of high school students “vape,” according to recent surveys. While many users perceive e-cigs as safer than traditional cigarettes, some of the flavorings that make them so enticing may have their own toxic consequences.

A growing number of studies find that some of the liquids used in e-cigarettes contain flavorings whose inhalation has been associated with lung problems, ranging from irritation to a rare but serious lung disease. For example, diacetyl, a butter-flavored chemical, has been linked to dozens of cases of bronchiolitis obliterans, a life-threatening obstructive lung disease. "

Sara Shipley Hiles reports for the Washington Post August 31, 2015.