Abstract
As the use of electronic nicotine delivery systems (ENDS) continues to increase, there is a need to evaluate their impact on indoor air quality. This study evaluated the differences in concentrations of volatile and particulate compounds (including formaldehyde, benzene, glycerol, propylene glycol, nicotine, and particulate matter) in secondhand vapor (SHV) after ad libitum subject vaping of cig-a-like ENDS, after-subject smoking of combustible cigarettes (CC), and after-subject non-smoking/non-vaping (blank) in an environmental test chamber. A single-center, open-label, parallel-group study was conducted. Seventy-one generally healthy smokers and vapers were randomized to one of six cohorts: Marlboro Gold Pack, Newport Box, Vuse non-menthol (14 mg nicotine/cartridge and 29 mg nicotine/cartridge), Vuse menthol (29 mg nicotine/cartridge), and market-sample ENDS. Concentrations of most secondhand constituents were similar after e-cigarette vaping and blank sessions. Constituent concentrations in SHV after ENDS use were significantly lower than in secondhand smoke (SHS) from CC, with the exception of glycerol and propylene glycol. Secondhand nicotine concentrations after ENDS use were 88–99% lower than after cigarette smoking. Emission factors between the three Vuse products were also similar with the exception of propylene glycol. Concentrations of some secondhand constituents after ENDS use were compared to existing indoor and occupational air quality guidelines and did not show potential to contribute appreciably to indoor air quality. These findings indicate that SHV from ENDS differs qualitatively and quantitatively from the SHS from CC.