HEALTH RISKS

The health risks of using e-cigarettes are controversial.

When using e-cigarettes, no substances are burned. Thus, unlike tobacco smoke, no carbon monoxide, hydrogen cyanide, arsenic or carcinogenic polycyclic aromatic hydrocarbons are produced.

According to a study published in October 2012, in which e-cigarette vapor was subjected to a risk analysis, it was found that no significant risks to human health exist.

Furthermore, in the cancer risk analysis conducted, the researchers found that none of the samples tested exceeded the risk limits for children or adults.

In the conclusion of the study, T.R. McAuley et al. concluded the following:
"For all byproducts measured, e-cigarettes cause very small exposures compared to tobacco cigarettes. This study shows that there is no discernible risk to human health from the e-cigarette compounds analyzed here."

The main component of the liquid to be vaporized is propanediol (older name: propylene glycol).
This substance is approved as food additive E 1520. It can cause allergic reactions in hypersensitive persons after application to the skin. When ingested orally, 1,2-propanediol is classified as harmless to humans. It is contained in chewing gum, creams, toothpaste, cigarettes and numerous medicines.

Inhalation of propanediol is a different story: In a study of volunteers exposed to a propanediol mist, concentrations of 0.31 mg/l irritated the eyes and throat. In a statement on shishas, the Federal Institute for Risk Assessment pointed out that inhalation of glycerol and 1,2-propanediol can lead to changes in the cell epithelium in the larynx and irritation of the nasal mucous membranes, even nosebleeds, in animal experiments.

As additional ingredients, manufacturers also add flavorings to the liquids, which are also approved as additives for foodstuffs.

Many liquids contain nicotine, but liquids without nicotine are also offered. According to an April 22, 2012, study, most of the e-cigarettes analyzed effectively deliver nicotine to the consumer. The researchers conclude that the amount of nicotine in the resulting aerosol is subject to wide variations depending on the manufacturer and model. E-cigarette consumers compensate for different nicotine strengths by selecting the hardware-liquid combination and thus arrive at a nicotine level similar to that previously achieved by smoking. Comparable to a tobacco smoker who inhales sometimes more - sometimes less deeply to reach a certain nicotine level.

In one study, the long-term effects of pure inhaled nicotine were examined in animal experiments. The scientists concluded:
"In summary, our study does not indicate any harmful effects of nicotine when administered in pure form by inhalation."

Zachary Cahn of the University of California at Berkeley and Michael Siegel of the Boston University School of Public Health evaluated 16 studies on e-cigarettes that looked at the ingredients in the liquid.

Two of the studies evaluated reported finding trace amounts of tobacco-specific nitrosamines (TSNA) in samples of nicotine-containing liquids. The maximum total TSNA content was 8.2 nanograms/g and at a similar level to that found in a nicotine patch (8.0 nanograms/patch). According to the evaluation, the nicotine-containing liquids and nicotine patches contained 0.07 to 0.2% of the total content of TSNA in tobacco cigarettes. The traces of TSNA can be explained by the extraction of nicotine from tobacco.

Finally, the authors point out that further studies and also regulations (in the USA) on e-cigarettes are needed.

According to the brochure Electric Cigarettes - An Overview, inhalation of the vaporized liquid can cause short-term side effects, such as irritation of the mouth and throat, dry cough, dizziness, and nausea.

In contrast, a February 2013 scientific assessment of lung function indicates that, unlike tobacco smoke and secondhand tobacco smoke, neither short-term (active) inhalation of vaporized liquid nor 1-hour (passive) exposure to e-cigarette vapor significantly disrupts normal lung function.

In a 2015 study, Public Health England confirmed that e-cigarettes are 95% less harmful than tobacco cigarettes and recommended government promotion.