Flavored E-Cigarettes Contain Chemical that Causes Popcorn Lung, Irreversible Lung Disease


In a study published on December 8, 2015 in Environmental Health Perspectives, a team of Harvard scientists found that flavored e-cigarette liquids contain the chemical that causes bronchiolitis obliterans, an irreversible obstructive lung disease popularly known as “Popcorn Lung.”

The flavorings-induced lung disease, bronchitis obliterans, has been tied to chemicals used to flavor e-cig liquid and involves flavorings exposure. The study, funded by the National Institute of Health Sciences, revealed that 75 percent of the 51 flavored liquids tested contain the chemical, diacetyl, and other harmful compounds. The flavors tested “included varieties with potential appeal to young people such as cotton candy, ‘Fruit Squirts,’ and cupcake,” the Harvard Gazette reports.

The name Popcorn Lung (or Popcorn Workers Lung) traces to the cases of eight former employees at a popcorn factory in Missouri that made artificial butter flavoring for microwave popcorn. The workers inhaled diacetyl from the flavoring product on a daily basis and developed wheezing, coughing, shortness of breath, night sweats, and weight loss, according to the National Institute for Occupational Safety and Health (NIOSH).

The symptoms of popcorn lung usually come on gradually and become progressively worse. Symptoms of popcorn lung include:

• Coughing (usually without phlegm)
• Shortness of breath on exertion
• Fever
• Night sweats
• Weight loss
• Difficulty blowing air out fast and no improvement with asthma medication

Breathing tests, chest X-rays, chest scans, and lung biopsies are usually needed in order to diagnose bronchiolitis obliterans. Patients are often diagnosed with such illnesses as pneumonia, asthma, or other lung ailments before doctors reach the diagnosis of popcorn lung. The condition is irreversible, and, according to NIOSH, most cases of Popcorn Lung show little or no response to medical treatment. While the coughing and wheezing may ease somewhat if the individual is no longer exposed to diacetyl, abnormalities on lung function tests persist. Some people with severe bronchiolitis obliterans have needed lung transplant.

The researchers tested 51 types of flavored e-cigarettes and e-liquids for the presence of diacetyl, acetoin, and 2,3-pentanedione in e-cigarette vapor. The Flavor and Extract Manufacturers Association lists acetoin and 2,3-pentanedione, two flavoring compounds, as “high priority,” for respiratory hazard in the workplace, according to the Harvard Gazette. To test for the chemicals, the researchers inserted each e-cigarette into a sealed chamber attached to a device that drew air through the e-cigarette for eight seconds at a time with a resting period of 15 or 30 second between each draw. The air stream was then analyzed.

People who “vape” with flavored e-cigarette liquids inhale diacetyl on a regular basis. Vaping mimics traditional cigarette smoking because of the vapor emitted when drawing on the device. Many e-cigarette users are teenagers and many states still permit e-cigarettes to be sold to minors. Under its authority to regulate a wider range of tobacco-related products, the U.S. Food and Drug Administration (FDA) is considering new regulations that would prohibit the sale of e-cigarettes to minors. Many hope that liquids that are diacetyl-free will be used in the devices and that fruit flavor diacetyl, alcohol flavor diacetyl, and candy flavor diacetyl, to name a few, will be banned from use in e-cigarettes.

Dr. David Christiani, MD, MPH, of the Harvard T.H. Chan School of Public Health, one of the researchers involved in the study and co-author of a paper based on the study, said that, in addition to the addictive substance nicotine, most e-cigarette liquids also contain “cancer-causing chemicals, such as formaldehyde.” Christiani says the study shows that flavoring chemicals may cause lung damage, according to the Harvard Gazette.