Some E-Cig Flavors Can Give You 'Popcorn Lung,' According to a New Study

Read: We Tried the Most Disgusting E-Cig Flavors So You Don't Have To

A new study by researchers at Harvard T.H. Chan School of Public Health shows that flavoring agents used in electronic cigarettes have been linked to lung disease, shooting further holes in the "vaping is totally safe, bro!" argument.

The study tested 51 types of flavored e-cigs and liquids from leading brands for diacetyl, acetoin, and 2,3-pentanedione—compounds which have proven to pose a respiratory hazard when inhaled. "At least one of the three chemicals was detected in 47 of the 51 flavors tested," the study found.

E-cig flavors like cupcake, cotton candy, and the exceedingly gross-sounding "fruit squirters" all tested positive for the presence of diacetyl, a chemical that causes a debilitating respiratory disease nicknamed "popcorn lung."

Cute as the name may seem, popcorn lung (or Bronchiolitis obliterans) can do serious damage to your insides when inhaled—it got its name after the diacetyl in microwave popcorn started wrecking the lungs of factory workers.

"Recognition of the hazards associated with inhaling flavoring chemicals started with 'popcorn lung' over a decade ago," Joseph Allen, lead author of the study, told the Harvard Gazette. "However, diacetyl and other related flavoring chemicals are used in many other flavors beyond butter-flavored popcorn, including fruit flavors, alcohol flavors, and, we learned in our study, candy-flavored e-cigarettes."

Many of the questions about e-cigs and their effect on health have, in the past, focused too narrowly on nicotine, according to the study.