Are e-cigarettes hazardous for your lungs?

All of the studies available on e-cigarettes acknowledge one thing: the vapour generated by an e-cigarette is considerably less harmful for the body than tobacco smoke. However, a large number of studies may contradict each other in the nitty-gritty of this “risk reduction”.

Complexity of the scientific debates
These commonplace contradictions in the field of science today are focused on a small set of compounds considered harmful for the body. They generally involve debates about possible formaldehyde concentrations in e-cigarette vapour, acrolein concentrations, or more generally about the presence of volatile organic compounds (VOCs). This discussions occasionally make media headlines, tending to make smokers forget one key fact. Tobacco smoke, generated by combustion, contains thousands of compounds that are harmful for the body. We can particularly mention nitrosamines, tars, fine particles or carbon monoxide (CO) to name but a few of the ingredients contained in a lethal cocktail for the body, and which are not found in e-cigarette vapour.

While there are some debates about the presence or concentration of certain compounds, firstly, they concern a very limited number of constituents. Secondly, the experimental protocols used in the studies do not follow a predefined standard. Depending on the type of device and how it is used, some concentrations can indeed increase; this applies for example to formaldehyde in the case of poor wick hydration with e-liquid (dry hit). In this way, failing standardised references, each investigator can thus follow a different protocol and therefore obtain results contrasting significantly with other studies. Therefore, this adds an extra layer of complexity to these debates. Finally, the very rapid development of devices and slow rate at which scientific publications are issued give rise to a time lag and findings which are sometimes far removed from reality.

Nicotine, even though it continues to be demonised among a certain school of thought in public health, tends to get forgotten in this assessment of absolute risk. On the other hand, nicotine tends to be cited more readily in general public health issues, such as the gateway effect or addiction.

In the case of propylene glycol, one of the main constituents of e-liquids, the scientific knowledge is quite advanced. Flavours, however, represent a line of research that has only emerged recently.

Lower risk does not necessarily mean zero-risk
This is the very heart of the public health problem in which e-cigarettes find themselves. Should they be examined in terms of absolute harmfulness or relative harmfulness (compared to smoked tobacco)? In the United States, for example, it is very common to read research focussing solely on the absolute risk, whereas other studies almost systematically examine the relative risk, compared to smoked tobacco, as in the UK or in France for example. Therefore, major differences of opinion stem from this approach.

Our opinion on the absolute risk: e-cigarette vapour is not as pure as fresh mountain air. For a non-smoker, inhaling e-cigarette vapour could pose a risk (albeit minor) for your health. In the short term, e-cigarette vapour would appear to have no effects on the cardiovascular system and no effects on the tissue of the airways, but this does not rule out any uncertainty on the long-term effects which are still unknown to date, and which will most likely never be known simply due to the ethical problems posed (having non-smokers vape over a very long period of time for experimental purposes). 

Our opinion on the relative risk: e-cigarette vapour should be viewed as a lower-risk alternative to smoked tobacco. According to studies in the UK, the risk reduction offered by e-cigarettes compared to smoked tobacco, could be 95%, or even more according to some scientific experts in the field. As such, the benefits offered by e-cigarettes mean that they offer considerable promise for public health, since tobacco use continues to be one of the leading preventable causes of mortality worldwide. If you are unable to quit smoking or you don’t want to quit, e-cigarettes can be a serious option to consider to improve your health, provided that they are used exclusively.

E-cigarettes are intended for smokers who, by smoking tobacco, are putting their lives at risk. E-cigarette vapour is substantially less harmful than tobacco smoke, and will hence be much less hazardous for the lungs. Most of the risks to which a smoker is exposed could very probably be prevented by switching completely over to e-cigarettes, provided that the tobacco habit is well and truly a thing of the past. Indeed, very few benefits would be obtained by alternating tobacco / e-cigarettes.

This article is not intended as medical advice. If in doubt, please consult a healthcare professional.