Free Radical, Carbonyl, and Nicotine Levels Produced by Juul Electronic Cigarettes

• Published in: Nicotine & tobacco research 2019-08, Vol.21 (9), p.1274-1278
• Main Authors: Reilly, Samantha M, Bitzer, Zachary T, Goel, Reema, Trushin, Neil, Richie, John P
• Format: Article
• Language: English
• Subjects: Brief Reports; Electronic Nicotine Delivery Systems; Flavoring Agents - administration & dosage; Flavoring Agents - analysis; Free Radicals - administration & dosage; Free Radicals - analysis; Humans; Nicotine - administration & dosage; Nicotine - analysis; Oxidative Stress - drug effects; Oxidative Stress - physiology; Propylene Glycol - administration & dosage; Propylene Glycol - analysis
• ISSN: 1469-994X; 1462-2203; 1469-994X
• DOI: 10.1093/ntr/nty221

Free radicals and carbonyls produced by electronic cigarettes (e-cigs) have the potential to inflict oxidative stress. Recently, Juul e-cigs have risen drastically in popularity; however, there is no data on nicotine and oxidant yields from this new e-cig design. Aerosol generated from four different Juul flavors was analyzed for carbonyls, nicotine, and free radicals. The e-liquids were analyzed for propylene glycol (PG) and glycerol (GLY) concentrations. To determine the effects of e-liquid on oxidant production, Juul pods were refilled with nicotine-free 30:70 or 60:40 PG:GLY with or without citral. No significant differences were found in nicotine (164 ± 41 µg/puff), free radical (5.85 ± 1.20 pmol/puff), formaldehyde (0.20 ± 0.10 µg/puff), and acetone (0.20 ± 0.05 µg/puff) levels between flavors. The PG:GLY ratio in e-liquids was ~30:70 across all flavors with GLY being slightly higher in tobacco and mint flavors. In general, when Juul e-liquids were replaced with nicotine-free 60:40 PG:GLY, oxidant production increased up to 190% and, with addition of citral, increased even further. Juul devices produce free radicals and carbonyls, albeit, at levels substantially lower than those observed in other e-cig products, an effect only partially because of a low PG:GLY ratio. Nicotine delivery by these devices was as high as or higher than the levels previously reported from cigarettes. These findings suggest that oxidative stress and/or damage resulting from Juul use may be lower than that from cigarettes or other e-cig devices; however, the high nicotine levels are suggestive of a greater addiction potential.