Comparison of the chemical composition of aerosols from heated tobacco products, electronic cigarettes and tobacco cigarettes and their toxic impacts on the human bronchial epithelial BEaS-2B cells.

The studies conducted and referred to in the context provide the following findings:

1. Sleiman et al., 2016; Talih et al., 2015 found that e-cigarettes can release high levels of aldehydes when the e-liquid is overheated. however, this overheating generates an unpleasant taste that would prevent such high levels of aldehydes from being consistently inhaled.
2. Geiss et al., 2016; Kosmider et al., 2014; Talih et al., 2016 reported that the heat generated on the evaporation coil affects the quantity of carbonyls formed in e-cigarette emissions.
3. Some studies, including Goniewicz et al., 2014; hutzler et al., 2014; Sleiman et al., 2016; Talih et al., 2015, reported higher carbonyl amounts in e-cigarette emissions. however, these findings have been questioned as they could be the consequence of using unrealistic or extreme conditions.
4. The emission of nineteen carbonyl compounds in the aerosols of hTP, 3R4F cigarette and e-cigarettes was analyzed and reported in Table 1. Fifteen compounds were quantified at levels between 2 and 15 times higher in cigarette smoke than in hTP aerosols. hexanal was the only compound measured at a higher level in hTP emission (22.2 ng/puff) than in 3R4F tobacco smoke (10.5 ng/puff), and benzaldehyde was generated in almost equivalent amounts by hTP and cigarette.

In summary, the studies suggest that e-cigarettes and hTP can release harmful and potentially harmful compounds, including aldehydes and carbonyls, especially when the e-liquid or tobacco is overheated. however, the overheating generates an unpleasant taste that would prevent such high levels of harmful compounds from being consistently inhaled. additionally, the emissions of hTP contain lower levels of harmful compounds compared to 3R4F cigarette smoke, except for hexanal and benzaldehyde, which were generated in almost equivalent amounts by hTP and cigarette. Further long-term studies in animal models are needed to confirm these findings and assess chronic exposures to emergent tobacco products.

Dusautoir R, Zarcone G, Verriele M, et al. Comparison of the chemical composition of aerosols from heated tobacco products, electronic cigarettes and tobacco cigarettes and their toxic impacts on the human bronchial epithelial BEaS-2B cells. J hazard Mater. 2021;401:123417. doi:10.1016/j.jhazmat.2020.123417