September 29, 2020
Konstantinos E. Farsalinos and Riccardo Polosa
What are Electronic Cigarettes?
An electronic cigarette is a battery-operated device that could be an alternative to smoked tobacco products such as cigarettes, cigars, or pipes. They are marketed as less harmful alternatives to smoking. Other terms for these products are Personal Vaporizer (PV), Vape, Nicotine Vaporizer, Mod, eHookah and Hookah stick.
The popularity of ECs may be due to their ability to deal both with the physical (i.e. nicotine) and the behavioral component of smoking addiction. In particular, sensory stimulation and simulation of smoking behavior and cigarette manipulation are important determinants of a product’s effectiveness in reducing or completely substituting smoking. These features are generally absent in nicotine replacement therapies (NRTs) and oral medications for nicotine dependence, whereas ECs provide rituals associated with smoking behavior and sensory stimulation associated with it.
When was it invented?
In 2003, Hon Lik, a pharmacist in China developed ECs to help him stop smoking. It was released in the Us and Europe around 2006. Since their invention, there has already been continuous modifications and development of more efficient and appealing products.
At present, there are mainly three forms of devices available.
1) First-generation devices, mimics the size and look of regular cigarettes and consists of small lithium batteries and cartomizers .
(2) Second-generation devices consist mainly of higher-capacity lithium batteries and atomizers with the ability to refill them with liquid.
(3) Third generation devices (also called ‘Mods’, for modifications), consisting of very large-capacity lithium batteries with integrated circuits that allow vapers to change the voltage or power delivered to the atomizer.
What are the parts of an Electronic Cigarette?
They consist of the battery part (usually a lithium battery), an atomizer, the part containing the heat element and the cartridge or tank where liquid is stored.
The liquid used mainly consists of propylene glycol, glycerol, distilled water, flavorings (that may or may not be approved for food use) and nicotine.
Consumers may choose from several nicotine strengths, including non-nicotine liquids, and a countless list of flavors; this assortment is a characteristic feature that distinguishes ECs from any other tobacco harm reduction products.
How does an electronic cigarette function?
The cartridge holds the liquid. The cartridge filler (the wick soaked in liquid) is in contact with the atomizer. The liquid is absorbed via the atomizer, when the vaper inhales on the EC it sucks the liquid. The atomizer heats the liquid to its boiling point and the liquid becomes vapor.
Are ECs safer than Tobacco cigarettes?
Conventional cigarettes are the most common form of nicotine intake. Smoking-related diseases are pathophysiologically attributed to oxidative stress, activation of inflammatory pathways and the toxic effect of more than 4000 chemicals and carcinogens present in tobacco smoke. In addition, each puff contains >1 × 1015 free radicals. All of these chemicals are emitted mostly during the combustion process, which is absent in ECs. It is anticipated that any product delivering nicotine without involving combustion, such as the EC, would confer a significantly lower risk compared with conventional cigarettes and to other nicotine containing combustible products.
Chemical studies have found that exposure to toxic chemicals from ECs is far lower compared with tobacco cigarettes. Besides comparing the levels of specific chemicals released from tobacco and ECs, it should be taken into consideration that the vast majority of the >4000 chemicals present in tobacco smoke are completely absent from ECs.
Toxicological studies have shown significantly lower adverse effects of EC vapor compared with cigarette smoke. More research is needed, including studies on different cell lines such as lung epithelial cells. In addition, it is probably necessary to evaluate a huge number of liquids with different flavors since a minority of them, appear to raise some concerns when tested in the aerosol form produced by using an EC device.
Clinical studies evaluating the effects of short-term EC use on selected cardiovascular and respiratory functional outcomes have shown that even if some harmful effects of vaping are reported, these are considerably milder compared with smoking conventional cigarettes. However, it is difficult to assess the prognostic implications of these studies; longer-term data are needed before any definite conclusions are made.
Passive smoking is an established risk factor for a variety of diseases. The potential of any significant adverse effects of EC on bystanders is minimal. Aerosol is produced only during activation of the device, while tobacco cigarettes emit smoke even when no puffs are taken.
Emissions from an EC only formaldehyde, acrolein, isoprene, acetaldehyde and acetic acid were detected. The levels were found to be 5–40 times lower compared with emissions from a conventional cigarette. The amount of TOC accumulated after 5 hours of EC use was similar to the amount found after just 11 minutes of smoking. They observed that the half-life of EC aerosol was 11 seconds compared with 20 minutes for cigarette smoke. Researchers found significant adverse effects in spirometry parameters after being exposed to passive smoking for 1 hour, while no adverse effects were observed after exposure to passive vaping.
Do doctors advise EC use?
The best advice should be total smoking cessation. The addictive potential is an important factor in any decision to endorse nicotine administration; however, it should be considered as slight ‘collateral damage’ with minimal impact to vapers’ health compared with the tremendous benefit of eliminating all disease-related substances coming from tobacco smoking. In fact, smokers are already addicted to nicotine; therefore, the use of a ‘cleaner’ form of nicotine delivery would not represent any additional risk of addiction.
Are ECs dangerous?
Increase in EC use has occurred despite the concerns raised by public health authorities about the safety and appropriateness of using these products as alternatives to smoking.
The electronic equipment of ECs may be the cause accidents. ECs are mainly composed of lithium batteries. There have been reports of explosions of batteries, caused either by prolonged charging and use of improper chargers or by design defects, similar with mobile phones.
Therefore, this does not occur specifically with ECs, however, quality standards of production should be used in order to avoid such accidents
Research will help make electronic cigarettes more effective as smoking substitutes and will better define and further reduce residual risks from use to as low as possible, by establishing appropriate quality control and standards.
Vapor generated from cartomizers of a popular EC brand using standard smoking machine protocol.
Systematic review of 35 chemical toxicity studies/technical reports of EC liquids/vapors.
TSNAs content in 105 refill liquids from 11 EC brands purchased in Korean shops.
Nicotine degradation product, ethylene glycol, diethylene glycol evaluation of 20 EC refill liquids from 10 popular brands.
Vapors generated from 12 brands of ECs and a medical nicotine inhaler using a modified smoking protocol.
Evaluation of 2 toxicants in the EC vapor from Ruyan16 mg and mainstream tobacco smoke using a standard smoking machine protocol.
Evaluation of toxicants in EC cartridges from 2 popular US brands.
Evaluation of 4 refill stations and 6 replacement cartridges advertised as containing Cialis or rimonambant.
Overview of 16 chemical toxicity studies of EC liquids/vapors.
Evaluation of PM fractions and PAHsin the vapor generated from cartomizer of an Italian EC brand.