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E-cigarettes emitted fewer carcinogenic particulates, higher toxic metals
Secondhand smoke from electronic cigarettes contained significantly fewer organic carcinogen emissions than tobacco-containing cigarettes, according to recent findings.
However, exposure levels to harmful metals in secondhand e-cigarette smoke were found to be significantly higher.
“Our results demonstrate that overall, electronic cigarettes seem to be less harmful than regular cigarettes, but their elevated content of toxic metals such as nickel and chromium do raise concerns,” researcher Constantinos Sioutas, ScD, professor at the University of Southern California Viterbi School of Engineering, said in a press release.
Sioutas and colleagues collected indoor particle samples on quartz filters in indoor and outdoor environments. A volunteer study group consisting of two men (aged 55 and 64 years) and one woman (aged 32 years) smoked e-cigarettes and tobacco cigarettes in the designated areas.
The e-cigarette smoking was timed to be comparable to tobacco smoking habits, with e-cigarettes vaped at one puff per minute, lasting for 7 minutes, followed by a 3-minute pause and resumption of smoking for another 7 minutes.
Six e-cigarette samples and three tobacco cigarette samples were collected, each with matched outdoor samples, and were evaluated for their chemical content.
The researchers found that normal cigarette samples had a 10 times greater total exposure to particulate elements than the e-cigarettes, but the e-cigarettes emitted higher concentrations of particulate metals, including nickel, zinc and chromium. Moreover, they determined that the e-cigarettes’ “e-liquid,” which consists of nicotine, propylene glycol, glycerol and flavorings, played a minimal role in the emission of the metals by e-cigarettes. This finding indicates that these emissions likely are attributable to some other aspect of the e-cigarettes.
“The metal particles likely come from the cartridge of the e-cigarette devices themselves — which opens up the possibility that better manufacturing standards for the devices could reduce the quantity of metals in the smoke,” Arian Saffari, a PhD student at University of Southern California Viterbi, said in the release. “Studies of this kind are necessary for implementing effective regulatory measures. E-cigarettes are so new, there just isn’t much research available on them yet.”
Notably, the researchers did not detect emissions of polycyclic aromatic hydrocarbons from the e-cigarettes, whereas the emission of polycyclic aromatic hydrocarbons from tobacco cigarettes was significant. Overall, the researchers found that e-cigarettes had significantly reduced secondhand smoke emissions in this real-world setting.
“Offices and rooms — not laboratories — are the environments where you’re likely to be exposed to secondhand e-cigarette smoke, so we did our testing there to better simulate real-life exposure conditions,” Saffari said in the press release.
Disclosure: The researchers report no relevant financial disclosures.