Tobacco is one of the main sources of toxic substances in the human body. Many people opt for the alternative, the electronic cigarette, to avoid health risks. But a new study reveals that vaping entails the inhalation of inorganic elements, especially rare earth elements, whose toxicity is still unknown.
The water vapour of electronic cigarettes is not harmless to humans. / Pixabay
The electronic cigarette is gaining more and more followers among the younger people, but it is mainly adults who use it the most for a simple reason: they believe that it helps them to stop smoking, as several studies have suggested.
Still, although water vapour pollutes the air less than conventional cigarette smoke, it is not harmless to humans. In fact, several published works had already established that the vapour contains substances such as diacetyl, glycerol, nicotine, nicotirine, and benzene, among many others.
However, until now it was not known if electronic cigarettes represent a source of emission of inorganic elements, contained in the liquids used or even as part of the electronic device.
A study, published in Environmental Research, has analyzed the blood of 150 people and detected the presence of 42 inorganic elements, including trace elements –necessary for the organism, but potentially toxic at high doses–, inorganic elements considered toxic by the Agency for Toxic Substances and Diseases Registry (ATSDR), and other, less frequent ones belonging to the group of rare earth elements within the periodic table of elements.
The blood analyses were carried out in collaboration with Dr. Mihaela Badea, from the Faculty of Medicine of the Transilvania University of Brasov in Romania, where the use of such devices is extremely widespread.
The results not only suggest that the conventional cigarette is a source of contamination of inorganic elements –as was already known for elements such as cadmium, among others–, but also that the use of the electronic cigarette is an external source of introduction of inorganic elements –particularly rare earth elements– into our organism.
“The interest of these 'rare' elements is that some of them are used in the manufacturing of electronic devices, and appear on the surface of the earth and in living beings as a consequence of the mismanagement of electronic waste,” as Luis Alberto Henríquez, co-author of the work and researcher at the Department of Clinical Sciences of the University of Las Palmas de Gran Canaria, has pointed out to SINC.
But what toxicity does the organism face with the presence of rare earths? “The answer is that this is not known,” Henríquez admits. At present, he says, “it is not known what rare earth elements are 'bad' or at what concentration. There are data for some, such as gadolinium, but this is an exception.”
When comparing blood samples from non-smokers (control group), smokers and users of e-cigarettes, the scientists showed that smokers have higher blood concentrations of copper, molybdenum, zinc, antimony and strontium; while users of electronic cigarettes have higher concentrations of metals such as selenium, silver and vanadium.
Moreover, the researchers detected chemical elements such as beryllium, europium and lanthanides more frequently among users of electronic cigarettes (20.6%, 23.5% and 14.7%, respectively) than among conventional cigarette smokers (1.7%, 19% and 12.1%, respectively).
The number of rare earth elements detected was also higher among users of electronic cigarettes (11.8% of them showed more than 10 different elements). Blood levels of cerium and erbium, for example, increased as the duration of use of electronic cigarettes was increased.
“We have found that smoking is primarily a source of heavy metals, whereas the use of electronic cigarettes is a potential source of rare earth elements. However, these elements were detected at low concentrations,” concludes Henríquez. The scientists insist that the consequences such findings may have on people’s health require additional studies.
Mihaela Badea et al. “Body burden of toxic metals and rare earth elements in non-smokers, cigarette smokers and electronic cigarette users” Environmental Research 166: 269-275 DOI: 10.1016/j.envres.2018.06.007 October 2018