There are over 7,000 electronic cigarette, or vaping, flavors on the market right now – fruit, candy, and cocktail, just to name a few. But while E-cigs are reportedly "95% less harmful than tobacco," researchers analyzing flavoring chemicals found compounds previously linked to lung disease in several dozen types of flavored E-cigs. The findings were published in Environmental Health Perspectives this week.
Back in the early 2000s, inhalation exposure to the flavoring chemical diacetyl in food products became associated with a serious disease that came to be called “popcorn lung.” Workers in a microwave popcorn processing plant were exposed to visible dust and particles – as well as vapors with a strong buttery odor – when oil, salt, and flavorings were mixed into large, heated tanks. Multiple factory workers developed a respiratory illness that resembled bronchiolitis obliterans, the symptoms of which include coughing, asthma and labored breathing. It can lead to irreversible loss of lung function that can become so severe that a transplant is the only possible treatment.
Despite the popularity of E-cigs – around $3 billion (£2 billion) was spent on them in 2013 in the U.S. alone – there’s been limited research on their flavoring chemicals. E-cigs aren’t regulated by the U.S. Food and Drug Administration, and concerns about their hazards have typically focused on nicotine exposure, second-hand exposure, and their potential to be a gateway to cigarette use.
Now, to investigate flavoring chemicals in E-cigs, a Harvard team led by Joseph Allen analyzed the air stream discharged from 51 types of flavored E-cigs sold by multiple leading brands. In addition to diacetyl, the team also studied 2,3-pentanedione and acetoin. All three chemicals are found in butter flavoring, as well as a variety of other flavors like caramel, butterscotch, pina colada, and strawberry. These E-cig cartridges are sold with names such as Cupcake, Fruit Squirts, Waikiki Watermelon, Cotton Candy, Tutti Frutti, Double Apple Hookah, Blue Water Punch, Oatmeal Cookie, and Alien Blood.
The team found at least one of the three flavoring chemicals in 47 of the 51 flavors tested. Diacetyl was detected in 39 of the flavors, while 2,3-pentanedione and acetoin were detected in 23 and 46 of the flavors, respectively.
Due to the associations between diacetyl and severe respiratory diseases, the team recommend “urgent action” to further evaluate its potentially widespread exposure via flavored E-cigs.