To demonstrate this, scientists at BAT used two smoking/vaping robots to produce either cigarette smoke from a 3R4F reference cigarette or e-cigarette vapour from Vype ePen and then measured the amount of deposited particle mass and nicotine on cells in the exposure chambers.
The results show that cigarette smoke and e-cigarette aerosol droplets are effectively delivered to cell surfaces¹. On a puff by puff basis and at a common dilution, the e-cigarette aerosol deposited greater mass but less nicotine than cigarette smoke, but the mass deposited was compositionally very different. E-cigarette aerosol droplets contain mainly humectants, water, nicotine and flavouring, whereas smoke droplets carry thousands of chemicals and hundreds of toxicants from combustion.
Having proven the delivery of aerosols to the exposure chamber, the scientists used the Ames test to compare the mutagenic potential of 3R4F reference cigarette smoke with that of vapour from the Vype ePen e-cigarette. Test bacteria were exposed to the same concentrations of whole aerosols or particulate matter extracted from either cigarette smoke or e-cigarette vapour.
Both cigarette smoke and particulate matter were mutagenic, with whole smoke taking just 24 minutes to cause an effect. E-cigarette vapour and particulate matter however, had no effect, even after three hours of continuous exposure².
“Because we have shown our system categorically delivers aerosols in our in vitro exposure systems, we can be confident in the results from this and other cell-based tests,” said Dr James Murphy, Head of Reduced Risk Substantiation at BAT.
1. Adamson, J., Thorne, D., Zainuddin, B., Baxter, A., McAughey, J., Gaça, M. Application of dosimetry tools for the assessment of e-cigarette aerosol and cigarette smoke generated on two different in vitro exposure systems. Chemistry Central Journal 2016, DOI: 10.1186/s13065-016-0221-9.
2. Thorne, D., Crooks, I., Hollings, M., Seymour, A., Meredith, C., Gaҫa, M. The mutagenic assessment of an electronic-cigarette and reference cigarette smoke using the Ames assay in strains TA98 and TA100. Mutation Research 2016, 812; 29-38