Electronic cigarettes are generally considered safer than conventional tobacco cigarettes. Much research has focused on e-cigarette gas-phase emissions, but less is known about particulate matter in the exhaled vapour.
New data reported in Environmental Science, Processes and Impacts (online, 22 August 2014)
suggest that e-cigarettes are associated with a “remarkable” 10-fold reduction in overall emission of metals and organic compounds compared with conventional cigarettes.
However, emission of two toxic heavy metals – chromium and nickel – was significantly higher with e-cigarettes than with normal cigarettes. Several other toxic metals, including lead and zinc, were also present in e-cigarette vapour.
“The metal particles likely come from the cartridge of the e-cigarette devices themselves,” remark Arian Saffaria from the University of Southern California, Los Angeles, and co-authors.
 Saffari A, Daher N. Ruprecht AA, et al. Particulate Metals and Organic Compounds from Electronic and Tobacco-containing Cigarettes: Comparison of Emission Rates and Secondhand Exposure. Environmental Science, Processes and Impacts. Available from: doi: 10.1039/C4EM00415A