Traces of hundreds of unknown chemicals have been found in vapors and aerosols from electronic cigarettes, according to the first study conducted by researchers at Johns Hopkins University, foreign media reported. The study details a large number of unidentified chemicals and a small number of known and potentially harmful compounds.
"Existing research compare to ordinary cigarette electronic cigarette, found that now the cigarette pollutants are much lower in the electronic cigarettes," the study's senior author Carsten Prasse said, "the problem is that electronic cigarettes contain a chemical that no other characteristics of aerosols, may be we don't know the health risks. More and more young people are using these e-cigarettes and they need to know what they're being exposed to."
This study is the first to use liquid chromatography/high resolution mass spectrometry to perform a thorough non-target analysis of all potential compounds present in e-cigarette liquids and aerosols. The researchers tested four popular tobacco-flavored e-cigarette liquids, as well as aerosols produced by four common e-cigarette devices.
Nearly 2,000 different compounds were found, most of which were unidentified. Of the chemicals the researchers were able to identify, six potentially harmful compounds were detected. They include a pair of condiments linked to respiratory irritation, three industrial chemicals, an insecticide and, perhaps most unusual of all, caffeine.
Mina Tehrani, lead author of the study, said two of the four liquids contained caffeine. Flavors like coffee or chocolate are known to contain trace amounts of caffeine, but Tehrani were surprised to find it in liquid smoke.
"This could be an undisclosed extra stimulus for smokers," Tehrani said. "We want to know if they intentionally add it."
Another unexpected finding of this study was the discovery of similar condensed hydrocarbons in e-flue gas sol. These compounds are usually produced during combustion, but are now found during smoking.
A similar recent study in Australia found at least one potentially harmful chemical in every e-cigarette sample studied. These include benzaldehyde, an airway irritant, and anti-cinnamaldehyde, an immunosuppressant. A total of 65 e-cigarette liquids were studied in the study. In addition, the study found traces of nicotine in six e-cigarette liquids tested.
These studies are certainly not the first time potentially harmful chemicals have been found in e-cigarette liquids. But it's important to note that these studies are designed to look for traces of any chemicals. They were not investigating whether the chemicals caused harm directly in the context of inhalation, or whether they were present in large enough quantities to assume harm was done in the first place.
Instead, Prasse points out, the study confirms how little we know about the chemicals used in e-cigarettes. While his study did not compare the harm caused by vaping with smoking cigarettes, Prasse stressed that e-cigarettes should not be considered a "healthy" alternative to traditional smoking.
"People just need to know that when they inhale, they are inhaling a very complex mixture of chemicals. And for a lot of these compounds, we don't really know what they are. I have reservations about vaping being marketed as healthier than smoking. In my view, we are not at the point where we can really say that, "he said.