New electronic cigarettes turned out to be more harmful than the old ones

Oleg Lischuk, N+1

American scientists have analyzed the content of aldehydes in aerosols of electronic cigarettes of different generations. It turned out that newer devices produce more of these substances than older ones, but less than is contained in the smoke of conventional cigarettes. The results of the work are published in the journal ACS Omega (Ogunwale et al., Aldehyde Detection in Electronic Cigarette Aerosols).

Since the introduction of electronic cigarettes on the market in 2004, there have been disputes between their supporters, who point to less harm compared to tobacco, and opponents, who claim that the degree of their harmfulness has not been established. Official medicine refrains from recommendations in this regard, taking a cautious position until sufficient data is obtained.

The greatest concern about the potential harm of electronic cigarettes is caused by aldehydes, which are formed when a flavored solution of glycerin and propylene glycol is heated in them (formaldehyde and acrolein are obtained mainly from the former, acetaldehyde from the latter). These substances (especially acrolein), which are also present in tobacco smoke, can increase the risk of cardiovascular diseases, however, due to instability, their content in the aerosol of electronic cigarettes remained unspecified.

To clarify the production of aldehydes, employees of the University of Louisville purchased a first-generation electronic cigarette with four different cartridges and a next-generation vaporizer (vape) with six refueling liquids. Aerosol from them was obtained using a standard laboratory robot simulating real smoking, and passed it through a microreactor with aminooxyethylmorpholinium chloride on a silicon substrate. This substance converts unstable aldehydes into more stable oxime adducts, the quantitative evaluation of which by gas chromatography is quite simple.

Results of gas chromatography and NMR spectroscopy (from an article in ACS Omega)

It turned out that electronic cigarettes of both generations produce formaldehyde, acetaldehyde and lower concentrations of acrolein, and there are more of these substances (as well as acetone) in the aerosol vapes. Scientists attribute this to the higher battery power: in old evaporators it is fixed and is 4.6 watts at a voltage of 3.7 volts, and in new ones it ranges from 9.1 to 16.6 watts at a voltage of 3.7 to 5 volts.

Flavoring additives had a certain effect on the aldehyde composition of steam, but they did not play a decisive role. The content of aldehydes in the aerosol of both types of electronic cigarettes turned out to be significantly lower than in the smoke of conventional cigarettes.

The content of carbonyl compounds in the aerosol of old (EU) and new (EL)
electronic cigarettes and tobacco smoke

Additional experiments with different tightening durations have shown that the maximum amount of aldehydes is produced at its duration of about four seconds. At the same time, e-cigarette smokers, according to the researchers, on average, are delayed from 3.5 to 4.3 seconds.

Since some aldehydes can react reversibly with glycerin or ethylene glycol to form semi-acetals, their detectable concentration may be lower than the real one. To exclude this, the scientists analyzed the content of these substances in the aerosol by 1H-NMR spectroscopy and made sure that a small amount of semi-acetals is formed by evaporation of only one of the modern solutions.

Thus, electronic cigarettes produce aldehydes, although in smaller quantities than conventional ones. The question of the degree of health risk that this carries remains open, since safe concentrations of aldehydes have yet to be determined.

Previously, scientists found that aerosols of "delicious" solutions for electronic cigarettes contain an increased amount of aldehydes. Another research team showed that vapers have fewer toxic and carcinogenic substances in their bodies than tobacco smokers. Based on a meta-analysis of 38 studies, scientists have concluded that e-cigarettes do not facilitate, but make it difficult to abandon conventional ones.

Portal "Eternal youth" http://vechnayamolodost.ru  19.04.2017