Electronic cigarettes’ effects on respiratory health

Abstract

BACKGROUND. Electronic cigarettes (ECs) are
electronic nicotine delivery systems (ENDS). ECs have
been sold as a safer alternative to traditional cigarettes
due to the lack of tobacco combustion since 2006.
Their use has risen dramatically not only among current
smokers willing to quit, but even among never-smokers
and adolescents. Anyway, few data are available on the
effects of ECs’ use on respiratory health. This article
aims to summarize the available evidence on this matter.
MATERIALS AND METHODS. We collected on
PubMed relevant studies and case reports on electronic
cigarette use and its effects on respiratory health.
RESULTS. Electronic cigarettes’ structure includes
several sources of toxicity. Its constituents are rich in
heavy metals, founded in various concentrations in
the aerosolized vapor. E-liquid used to refill EC’s cartridge
is made of propylene glycol (PG) and vegetable
glycerin (VG), which irritate the respiratory system.
Moreover, e-liquid taste is often ameliorated with a
wide range of commercial or homemade flavors, whose
safety is uncertain. Several studies revealed that ECs
vapor induces harmful effects at different levels of the
respiratory tract, from airways to lung parenchyma, altering
the pulmonary homeostasis. E-cigarette, or vaping,
product use-associated lung injury” (EVALI) is a
pulmonary disease described for the first time in 2019,
characterized by the presence of bilateral ground-glass
opacities on chest imaging, affecting people with a history
of ECs in the previous 90 days. Moreover, current
literature suggests a potential carcinogenic role of ECs
and describes vaping as a risk factor from asthma developing
and exacerbations.
CONCLUSIONS. From available data, ECs should
not be considered a harmless alternative to tobacco cigarettes.
There is an urgent need for further studies to
establish the long-term effects of vaping.