Comparative toxicity between electronic cigarette and

conventional cigarette

The number of scientific studies on the toxicity of e-cigarettes remains low due to methodological problems (small study, contradictory results, lack of long-term follow-up, conflicts of interest). Nevertheless, toxicity studies have generally been carried out in the laboratory on animals or on cell cultures exposed to liquids and fumes from e-cigarettes and refills. In 2018 Kamilari et al, demonstrated by total reflection X-ray fluorescence spectroscopy the presence of heavy metals in e-cigarette refill liquids. The elements of interest are cadmium (Cd), lead (Pb), nickel (Ni), copper (Cu), arsenic (As) and chromium (Cr) considered harmful to human health.

The aerosol, commonly called "vapor", emitted by the e-cigarette at a temperature of about 60 degrees, contains toxic substances common to those of the combustion of conventional cigarettes such as carbon monoxide or tars. As for the main component of e-liquids: propylene glycol, also used as a food additive, it does not seem to have any short-term toxicity at a temperature of 60 degrees, the degradation of glycerol into toxic products only being significant. -over 250 degrees. The concentrations of carcinogens (formaldehyde, acetaldehyde, acrolein, toluene, nitrosamines) are 9 to 450 times lower than with traditional cigarettes (Pisinger, 2014). Other chemicals identified in the composition of aerosols such as diacetyl, acetaldehyde, lead, antimony, arsenic, nickel, chromium and cadmium are regulated by AFNOR standards. However, current scientific knowledge remains insufficient on the effects of these molecules over the long term.

Electronic cigarette and health impacts

Compared to conventional tobacco and its still preferred mode of consumption (combustion), e-liquids have the advantage of reducing the risk of serious pathologies, in particular cancer. (McRobbie, 2014; Orellana-Barrios, 2015)

Tobacco-related cancers are due to the presence of numerous carcinogenic substances (benzene, arsenic, chromium, carbon monoxide and fine particles) produced by the main smoke responsible for cardiovascular diseases, respiratory insufficiencies and lung cancer (see Tobacco sheet). These products do not exist at significant levels in the "vapor" of e-cigarettes. These risks are therefore expected to be reduced in tobacco smokers who switch to e-cigarettes. However, the health effects of prolonged use of this device are not yet known, which is why health experts currently advise against it for non-smokers (INCa, 2017). A study points out that cancer patients have a positive attitude towards these devices and use them as an aid to quit smoking (Correa, 2018). What about juul dangers

Sussan et al. (2015) show the alteration of immune defenses for pulmonary pathologies in mice exposed for two consecutive weeks to electronic cigarette vapor. A study by Yu et al. shows that the components of electronic cigarettes, regardless of the presence of nicotine, can cause DNA strand breaks in the epithelial cells of the mouth and lung (keratinocytes). The e-cigarette can generate enough heat to pyrolyze carcinogens from the fluid or other components of the e-cigarette. (Yu et al., 2016). Kamilari et al, 2018 have shown that propylene glycol can cause allergic reactions in children, irritation of the respiratory tract.

According to the literature review by Pisinger (2014), comparative studies in smokers who have never used electronic cigarettes and vapers have shown various alterations of the respiratory tract which are reminiscent of those observed with smoking. A study including both healthy volunteers and patients with asthma and chronic obstructive pulmonary disease (COPD) also showed that 10 minutes of vaping induces significant airway obstruction (Hua, 2016). In its 2016 opinion, the High Council for Public Health (HCSP) underlines that recent studies have shown that certain components of e-liquids could be toxic, such as diacetyl. If inhaled after being heated, it can cause lung damage.

Health alert launched in the United States linked to the use of electronic cigarettes 

In the United States, health authorities have issued a health alert concerning an epidemic of severe pneumonia among vapers. . This alert was launched by the Centers for Diseases Control (CDC) and the American health control centers on Friday September 27, 2019. As of October 01, 2019, 1080 cases including 18 deaths have been reported . Public Health United states underlines that "To date, neither the CDC, nor the Food and Drug Administration (FDA) have advanced a certain explanation as to the origin of these severe pneumopathies", 

In United states, no epidemic has been detected, but the French health authorities are strengthening the system for monitoring suspected cases of severe pneumonia linked to the use of electronic cigarettes .

On October 11, 2019, the Directorate General of Health in conjunction with Public Health United states, other agencies and learned societies of pulmonology, resuscitation and emergency physicians (SRLF, SPLF and SFMU), set up a reporting system and investigation of cases of severe pneumonitis occurring in persons practicing vaping. This new system is only dedicated to reporting following the current alert in the United States. Its objective is to detect the possible emergence of severe pneumopathies in United states and to carry out the necessary investigations to identify the cause (s).