In today's society, more and more people are doing away with their harmful vices, and smoking happens to take the top spot. Smokers usually start weening themselves from the habit by using patches, gums, or the popular electronic cigarettes.

These kinds of cigarettes are becoming more interesting for users because of its unique feature. These cigarettes come in different flavors. However, it was recently found that flavored electronic cigarettes come with a compound suspected to cause a lot of respiratory problems. This study was published in the journal Environmental Health Perspectives.

Based on the test made by scientists from the Harvard T.H. Chan School of Public Health, 51 brands of flavored e-cigarettes and refill liquids contain diacetyl and two other chemicals, acetoin and 2,3-pentanedoine. It was also found that 90% contained one out of three substances when users inhale it. These chemicals were always used as flavor enhancers, specifically for products that need a buttery taste such as, microwavable popcorn.

Even though they are believed to be edible and safe, there are evidences pointing out that inhaling diacetyl, as what is happening to employees working in the popcorn manufacturing plants, may cause the development of an incurable and progressive lung disease called Obliterative Bronchitis (OB), also known as Bronchiolitis Obliterans, or more commonly, "Popcorn Lung."

According to a statement issued by the lead author of the study and assistant professor of exposure assessment science Joseph Allen, a decade has passed since the health hazards connected to inhaling flavoring chemicals with "Popcorn Lung" was first identified. But diacetyl is not only used in butter-flavored popcorn, it is also used in many flavoring chemicals, flavors like fruit, alcohol, and from the study, candy flavored e-cigarettes.

In the year 2000, there were eight ex Gilster-Mary Lee popcorn plant - employees who were diagnosed with OB by the Missouri Department of Health and Senior Services. After a joint investigation in partnership with the National Institute for Occupational Safety and Health (NIOSH), it was discovered that those currently working for the plant and exposed to flavoring vapors are most likely to report a much worse airway function.

In a different research, mostly in animals, it was found that diacetyl inhalation is the leading cause of worsening lung function. 2,3-pentanedione was also found to be potentially harmful.