Tobacco-Specific Nitrosamines in Electronic Cigarettes: Comparison between Liquid and Aerosol Levels.

Konstantinos Farsalinos,Konstantinos Poulas,Vassilis Voudris,Gene Gillman

doi:10.3390/ijerph120809046

Abstract

Introduction: Although electronic cigarette (EC) liquids contain low levels of tobacco-specific nitrosamines (TSNAs), studies evaluating the levels emitted to the aerosol are scarce. The purpose of this study was to compare the levels of TSNAs between liquids and generated aerosol. Methods: Three EC liquids were obtained from the market. An additional (spiked) sample was prepared by adding known amounts of standard TSNAs solutions to one of the obtained liquids. N-nitrosonornicotine (NNN), N-nitrosoanatabine (NAT), N-nitrosoanabasine (NAB) and 4-(methylnitrosamino)1-(3-pyridyl)-1-butanone (NNK) were measured. Three 100-puff sets from each liquid were trapped in filter pads and were subsequently analyzed for the presence of TSNAs. The expected levels of TSNAs (calculated based on the liquid consumption) were compared with the measured levels in the aerosol. Results: Only NAB was found at trace levels in two commercial liquids (1.2 and 2.3 ng/g), while the third contained 1.5 ng/g NAB and 7.7 ng/g NNN. The 100-puff sets resulted in 336–515 mg liquid consumption, with no TSNAs being detected in the aerosol. The spiked sample contained 42.0–53.9 ng/g of each of the TSNAs. All TSNAs were detected in the aerosol with the measured levels being statistically similar to the expected amounts. A significant correlation between expected and measured levels of TSNAs in the aerosol was found (r = 0.83, p < 0.001). Conclusion: The findings of this study show that exposure of EC users to TSNAs can be accurately assessed based on the levels present in the liquid, without the need to analyze the aerosol.

Highlights

Electronic cigarette (EC) liquids contain low levels of tobacco-specific nitrosamines (TSNAs), studies evaluating the levels emitted to the aerosol are scarce
There is some controversy as to whether combustion leads to substantial TSNAs formation [8,9,10], it seems likely that most TSNAs found in mainstream smoke come from the compounds present in cured tobacco leaves while only a small fraction is derived from pyrolytic synthesis [11]
This is the first study which directly compared the levels of TSNAs between electronic cigarette (EC) liquids and the respective aerosol

Summary

Introduction

Electronic cigarette (EC) liquids contain low levels of tobacco-specific nitrosamines (TSNAs), studies evaluating the levels emitted to the aerosol are scarce. Tobacco-specific nitrosamines (TSNAs), which are very potent carcinogenic chemicals [3,4], are present in minute amounts in EC liquids, usually at levels comparable to pharmaceutical nicotine products [5,6,7]. TSNAs are derived from the tobacco leaves They are naturally occurring compounds found in cured tobacco. There is some controversy as to whether combustion leads to substantial TSNAs formation [8,9,10], it seems likely that most TSNAs found in mainstream smoke come from the compounds present in cured tobacco leaves while only a small fraction is derived from pyrolytic synthesis [11]. The levels emitted to tobacco cigarette smoke directly correlate with the levels present in the tobacco leaves, but the absolute levels are usually considerably lower [11]

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