In the first study of bacterial contamination of Juul e-cigarettes, public health researchers have found contamination in the brand’s nicotine vaping liquids, according to research posted online in the Abstract Issue of the American Journal of Respiratory and Critical Care Medicine.

Although the researchers previously looked at market data for e-cigarettes in the US, no data were available on microbial impurities in market-dominant Juul products. They decided to study the possible contamination of these products.

David Christiani, MD, MPH, Elkan Blout Professor of Environmental Genetics in the Department of Environmental Health, Harvard T.H. Chan School of Public Health led a study in which he and Mi-Sun Lee, PhD, MPH, research associate at the school collected samples of all available Juul pod products four times. Pods are one-time use products that contain nicotine vaping liquids and are attached to the vaping device. The scientists included a range of flavors and analyzed each for the presence/amount of endotoxins (toxins inside a bacterial cell that are released when the cell disintegrates) and glucan, a component of fungal cell walls. 

They found that endotoxins were below detectable levels, while glucans were over the limit of detection in 25 products. Tobacco and menthol-flavored JUUL products had significantly higher levels of glucan compared to other JUUL products. They conducted an analysis that included data from their previous study, finding that glucan concentrations were 78 times higher in tobacco-flavored pods and 34 times higher in menthol-flavored pods than in products that were fruit-flavored.

“We found that tobacco and menthol-flavored Juul products were far more contaminated,” said Dr. Lee.  “We are particularly concerned because tobacco-flavored Juul products were excluded from the proposed FDA ban.  Finding these toxins in nicotine vaping pod products adds to the growing evidence of potentially harmful exposures in e-cigarettes.”

Glucan has been found, in occupational studies, to cause airway inflammation and lead to long-term lung damage.

Due to the nature of this study, the researchers were unable to determine where the impurities came from.   

  1. Abstract #10365. “Microbial Toxins In JUUL Nicotine Vaping Products in the USA.”