high-Nicotine Electronic Cigarette Products: Toxicity of JUUL Fluids and aerosols Correlates Strongly with Nicotine and Some Flavor Chemical Concentrations

Introduction:
This article reports a study on the toxicology of JUUL electronic cigarettes (ECs), which have gained widespread popularity in recent years, particularly among adolescents. The study aimed to identify and quantify the flavor chemicals and nicotine concentrations in the eight currently marketed prefilled JUUL EC cartridges, and to evaluate the cytotoxicity of the different variants using in vitro assays.

Key Points:

* The study identified 59 flavor chemicals in JUUL pod fluids, with three being >1 mg/mL.
* Nicotine concentrations in JUUL pod fluids were significantly higher than those of any EC products previously analyzed.
* The transfer efficiency of individual flavor chemicals and nicotine from the pod fluid into aerosols was generally 35-80%.
* all pod fluids were cytotoxic at a 1:10 dilution (10%) in the MTT and neutral red uptake assays when tested with BEaS-2B lung epithelial cells.
* Most aerosols were cytotoxic in these assays at concentrations between 0.2 and 1.8%.
* The cytotoxicity of collected aerosol materials was highly correlated with nicotine and ethyl maltol concentrations and moderately to weakly correlated with total flavor chemical concentration and menthol concentration.
* The study highlights the need to determine if JUUL products will lead to adverse health effects with chronic use.

Main Message:
The study demonstrates that some JUUL flavor pods have sufficiently high concentrations of flavor chemicals that may make them attractive to youth and that the concentrations of nicotine and some flavor chemicals are high enough to be cytotoxic in acute in vitro assays. This emphasizes the need for further research to determine if JUUL products will lead to adverse health effects with chronic use and the importance of regulating nicotine and flavor chemical concentrations in EC products to protect public health.

Omaiye, Esther E., Kevin J. McWhirter, Wentai Luo, James F. Pankow, and Prue Talbot. “high-Nicotine Electronic Cigarette Products: Toxicity of JUUL Fluids and aerosols Correlates Strongly with Nicotine and Some Flavor Chemical Concentrations.” Chemical Research in Toxicology 32, no. 6 (June 17, 2019): 1058–69. https://doi.org/10.1021/acs.chemrestox.8b00381.