Its formal name is bronchiolitis obliterans. Its nickname is "popcorn lung." It's an irreversible respiratory condition that causes the tiny air sacs in the lungs to become scarred.

It was discovered in 2000 after employees at a Missouri factory inhaled butter flavoring for microwave popcorn on a daily basis. Workers developed several symptoms including wheezing, coughing and shortness of breath.

Experts later learned the butter flavor contained a chemical called diacetyl. That chemical, and two other harmful compounds, were found in 75 percent of the e-cigarette flavored liquids studied in this project. (Video via The New Yorker)

The scientists tested 51 types of flavored e-cigs and liquids by placing each into a sealed chamber attached to a device that drew air through the e-cig for eight seconds at a time with a resting period of 15 or 30 seconds between each draw. After that, the air stream was analyzed.

Since many states still sell e-cigs to minors, researchers purposefully tested flavors "with [the] potential appeal to young people such as cotton candy, Fruit Squirts and cupcake." (Video via CNN)

Forty-seven of the 51 flavors tested contained at least one of the potentially harmful chemicals.

>> Watch the video on YouTube.

The video includes images from Getty Images.