A study carried out by PUC-Rio researchers in partnership with Furg (Federal University of Rio Grande) concluded that the liquids contained in electronic cigarettes available on the Brazilian illegal market are toxic even before being heated, a step to generate the aerosol inhaled by users.
Published in the journal Toxicology, the research is the first comprehensive analysis in the country on the toxicity of these liquids, according to the authors. The samples were obtained through direct donations from users and were classified by information on the label and by their origin after collection: Brazil, China, Europe, Paraguay and United States.
The set of substances represents materials available in Brazil, whether through smuggling, illegal production or after passing customs as material intended for individual consumption.
In the country, the sale, import and advertising of DEFs (electronic smoking devices) have been banned by Anvisa (National Health Surveillance Agency) since 2009. Despite the ban, consumption has reached its highest level since 2019, when control began, according to data from the Ministry of Health.
The researchers used two types of cells to test the toxicity of liquids by exposing them to different increasing dosages: yeast (Saccharomyces cerevisiae) and rat cells. Factors such as growth, metabolism and cellular integrity were assessed, as well as whether damage is caused by oxidative stress.
The results demonstrated that the toxicity of liquids is determined by the concentration and specific chemical composition of the product and increases as the concentration increases in all groups.
Vape liquids are composed of vegetable glycerin and propylene glycol solvents, but also additives such as food flavors, aromatic additives, nicotine, agents that promote the cooling sensation, among other substances. Researchers have discovered that toxicity is inherent in solvents and is increased by the presence of additives.
Exposure of cells to liquids resulted in reduced cell viability and mitochondrial activity, and toxicity was observed both in products from countries where sale is prohibited and countries where it is regulated.
The research is consistent with other discoveries, particularly with regard to the mechanisms of cellular toxicity and the chemical composition of “e-liquids”.
As limiting factors, the authors highlight the limited number of samples (15) and the fact that it is not a clinical study, that is, it does not specifically evaluate the impacts on the human body. New investments are already being made to develop research in this area, explains lead author, chemist Carlos Leonny Raimundo Fragoso.
“We are now investigating the role of metals in liquids, because we found that liquids made from disposable materials contain a very high amount of metals. So we will now evaluate the toxicity specifically of the metals that we found and we are moving towards doing a biomarker study for e-cigarettes,” he says.
Advisor Adriana Gioda, a professor at PUC-Rio, says the research had to be delayed due to the researchers’ delay in getting approval from Anvisa to study the samples. “This first published study only concerns donations, few samples, but we have already seen that it could have an effect on health,” he specifies.
The low number of samples, Fragoso adds, is due to the rigorous screening that had to be carried out. Researchers did not accept, for example, donations of opened vials. In total, there were three samples from five countries, which allowed the researchers to see that toxicity was not linked to product quality.
“The product sold in the United States is of very high quality because there is quality control in production, however, some liquids have higher toxicity than products in Brazil, so the toxicity exceeds the barrier of quality control, which shows that the raw material itself and the electronic cigarette have their toxicity,” he affirms.
According to cardiologist Jaqueline Scholz, a specialist in tobacco treatment who was not involved in the study, the research is able to prove that, whether the product is legal or not, DEF is not good for your health. The motto of harm reduction in relation to traditional cigarettes would therefore be wrong.
“It is a national study and it is interesting from a methodological point of view, although it has the limitation of not being intended for humans, but it can prove the toxicity of the product with the methodology, whether the product is on the legal or illegal market,” he says.
In a study this year, a team of scientists analyzed smoke from popular vaporizers and found high levels of heavy metals. Other studies have suggested the device could affect the heart, lungs and brain.
Data on long-term health effects is limited because the devices are relatively new and constantly evolving. Many people who use them are teenagers or in their 20s; it may take some time before other effects become apparent.
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