NCDs Tobacco

The electronic cigarette: a concern for health care professionals and public health

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Electronic nicotine delivery systems (ENDS), better known as electronic cigarettes or e-cigarettes, are devices that heat a solution (e-liquid) to create an aerosol, usually composed of propylene glycol or glycerol and flavourings, generally with nicotine.1  This is then inhaled by the users, in a process called ‘vaping’. 

The whole assortment of Tobacco Products – Source: US FDA

Although e-cigarettes are generally considered to be a single category of products, e-cigarettes can differ significantly in the production of toxicants and delivery of nicotine.2  Since their introduction on the market, three generations of e-cigarettes have been released: first-generation ‘cigalikes‘, second-generation ‘tank systems‘ and large third-generation ‘personal vaporizers‘.  The latter generations may be either closed and open systems. Unlike closed systems, open systems provide a customisable vaping experience by increasing the degree of control that users have over the e-liquid used and the voltage and resistance applied to heating the e-liquid, among other additional ventilation features.The degree of control that open systems provide, and the user’s puffing style can determine whether or not there is a speedy delivery of sufficient nicotine to mimic the sensory feel of smoking.2

Not a safe substitute

Typical use of untouched e-cigarettes produce aerosols that generally includes glycols, aldehydes, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbon (PAHs), tobacco-specific nitrosamines (TSNAs), metals, silicate particles and other elements.Dicarbonyls (glycoxal, methyglyoxal, diacethyl) and hydroxycarbonyls (acetol) are also found in e-cigarettes’ aerosols.2 

Electronic Cigarettes, What is the bottom line informational pamphlet from the US Center for Disease Control and Prevention

E-cigarettes come in many flavours with adolescents and adults generally preferring sweet flavours.3  Most of these flavourings are generally deemed to be safe by the U.S.  Food and Drug Administration only when ingested (i.e. as flavourings used in food). The majority have not been studied for safety when inhaled.4  In fact the presence of diacethyl, which is found in most flavoured samples, has been found to cause the lung condition ‘popcorn lung’.5

E-cigarettes have also been widely portrayed by the media as being liable to exploding.  Although these are relatively rare events, 164 cases have been formally reported.6  Several cases reported e-cigarette contact with metallic objects (e.g. coins, car keys) in trouser pockets at the time of explosion.  Burns were typically of second-degree severity or a combination of second and third degree burn.6

164 cases have been formally reported into publications

Number of Exploding Accidents with e-Cigarettes

Moreover among non-smokers there is a growing concern on the possible adverse health effects of being exposed to e-cigarettes’ aerosols.  The Maltese Legal Notice no. 22 of 2010 (Simulating Cigarettes or Tobacco Regulation) in the Tobacco (Smoking Control) Act (Cap. 315) states that any substitute to a conventional tobacco product (thus including e-cigarettes) must comply with the Tobacco Act and its regulations.7  Hence, e-cigarette users must also comply with this Act, which for example prohibits the use of a tobacco product in indoor public places.  Similarly, other European countries have also enacted laws/regulations which prohibit the use of e-cigarettes in public places.  Moreover a new directive on tobacco products 2014/40/EU laid by the European Parliament and the Council was issued to further include tobacco and related products which were not previously regulated, thus including electronic cigarettes.8  In spite of regulations that deter use and protect non-smokers, a recent European survey reveals that the public perception of being exposed to e-cigarette aerosols is high.9   31.0% of participants had seen people using e-cigarettes in general public places,  while 19.7% had seen others using e-cigarettes in indoor places where it is forbidden. 9   Using an electronic cigarette may expose non-users to the constituents (or toxicants) of the e-cigarette aerosol such as propylene gyclol and nicotine.10 Short-term passive exposure is associated with mild ocular, nasal and airway symptoms that persists for up to 30 minutes.11  Further research is needed to investigate long-term health implications.11

When compared to conventional cigarettes, the chemical analysis of carcinogenic profiles and their association with health parameters, indicate that e-cigarettes convey a lower potential disease burden than conventional tobacco cigarettes.12  However it is premature to speculate on how harmful vaping is when compared with smoking, as much remains subject to interpretation 5  and e-cigarettes have not been in the market for long.

It is likely that most e-cigarettes are less harmful to human health than conventional cigarettes, however this does not mean that e-cigarettes are a safe option.1,2,5  Risk of harm depends not only on the brand, batch, or preferred flavour, but also on other factors such as, the heating capability of the e-cigarette, the vaporizer, how worn out the e-cigarette is, and the method of use.5  Moreover as most e-cigarette users continue to smoke conventional cigarettes, the health risks of dual use must be taken into account in the assessment of the harm of vaping.5  In fact, long-term use of e-cigarettes is expected to increase the risk of chronic obstructive pulmonary disease, lung cancer, and possibly cardiovascular disease as well as some other diseases associated with smoking.13

Changing habits

A recently-published longitudinal correlation study conducted in England found that e-cigarettes were equally effective to varenicline in achieving high abstinence rates following a quit attempt.14  In fact Public Health England has suggested that smoking cessation practitioners and health professionals receive education and training in the use of e-cigarettes for smoking cessation, as an add-on to the provision of behavioural support.15 Moreover a recent randomized control trial, comparing e-cigarettes to nicotine replacement therapy, found that e-cigarettes were more effective smoking cessation tools 16, raising confusion amongst health care professionals. 

However, these results should be interpreted with caution.  It is important to point out that 80% (63 of 79) of those who quit smoking using e-cigarettes were still using e-cigarettes at 1 year follow-up while only 9% (4 of 44) were using nicotine replacement in the nicotine replacement group.16  This suggests that unlike most participants who used nicotine replacement, those who quit using an e-cigarette still required its use (after 12 months), either because of unresolved nicotine addiction or because of the ‘hand to mouth’ habit.  A longer follow-up period is required to make definite recommendations especially since vaping for more than one year after quitting smoking has been associated with smoking relapse.17  

In fact, both the World Health Organisation (WHO) and the European Public Health Association (EUPHA) state that there is lack of quality scientific evidence to confirm that e-cigarettes may help most smokers to quit or prevent them from quitting.1,2  EUPHA adds that for most persons, e-cigarettes might actually increase the subsequent use of conventional tobacco cigarettes.1  

A public health concern

“If the great majority of tobacco smokers who are unable or unwilling to quit would switch without delay to using an alternative source of nicotine with lower health risks, and eventually stop using it, this would represent a significant contemporary public health achievement.  This would only be the case if the recruitment of minors and non-smokers into the nicotine-dependent population is no higher than it is for smoking, and eventually decreases to zero.”2

E-cigarettes cannot be considered such an ‘alternative source of nicotine’, reason being that the majority of those who quit smoking using e-cigarettes, tend to keep on vaping in the long term,16 possibly risking relapse.17  Additionally, if e-cigarettes caused more people (non-smokers) to start smoking conventional cigarettes, the net public health effect would be lost.4

E-cigarettes are expanding the nicotine market by attracting adolescents who were at low risk of initiating nicotine use with conventional cigarettes, but many of whom are now moving on to conventional cigarettes.1,18  In fact many e-cigarettes come in child-friendly flavours, making them more appealing to young people.  Some new e-cigarettes also come in discreet, novel forms and shapes (e.g. looking like a USB flash drive). Even if youths do not progress to smoke conventional cigarettes, promoting nicotine use (which harms the developing brain) to youths is bad public health policy.Furthermore, nicotine and other potentially harmful compounds in e-cigarette liquids claimed to be ‘nicotine free’ have been identified in these products.19

E-cigarettes are expanding the nicotine market by attracting adolescents who were at low risk of initiating nicotine use with conventional cigarettes, but many of whom are now moving on to conventional tobacco cigarettes

In summary…

E-cigarettes are mostly nicotine based and their use amongst non-smokers (youth in particular) increases the risk of subsequent use of conventional tobacco products, thus  posing a threat to public health.  On an individual level, e-cigarettes may potentially be less harmful than cigarettes and could possibly assist in smoking cessation in the short-term, however the user will progress from one habit to another (smoking to vaping), possibly reverting to smoking in the long term.  If a smoker is concerned about the harmful health effects caused by smoking and is contemplating about changing his/her habit, he/she would benefit more from direct behavioural support, rather than merely advising him/her to switch habit to using e-cigarettes. 

All health care professionals can provide the required behavioural support, assisting smokers to reflect upon their ambivalence on smoking and any health concerns, as well as advising smokers to go for approved pharmacological treatment and intensive behavioural support.  Combination nicotine replacement therapy and varenicline are equally effective as quitting aids.20  Smoking cessation interventions that combine pharmacotherapy and behavioural support increase smoking cessation success when compared to a minimal intervention or usual care.21  

The Health Promotion and Disease Prevention Directorate provides free intensive behavioral support for smokers who wish to quit smoking.  More information on this service can be found here

Featured Photo by Thorn Yang from Pexels



  1. European Public Health Association (EUPHA).  Facts and fiction on e-cigs; 2018.  [cited 2019 May 8].  Available from:
  2. World Health Organisation (WHO).  Electronic Nicotine Delivery Systems and Electronic Non-Nicotine Delivery Systems (ENDS/ENNDS).  Report by WHO; 2016.  [cited 2019 May 8].  Available from:
  3. Zare S, Nemati M, Zheng Y.  A systematic review of consumer preference for ecigarette attributes: Flavor, nicotine strength, and type. PLoS ONE.  2018; 13(3): e0194145. 10.1371/journal.pone.0194145
  4. National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Board on Population Health and Public Health Practice; Committee on the Review of the Health Effects of Electronic Nicotine Delivery Systems; Eaton DL, Kwan LY, Stratton K, editors. Public Health Consequences of E-Cigarettes. Washington (DC): National Academies Press (US); 2018 Jan 23. [cited 2019 May 8].  Available from: doi: 10.17226/24952 
  5. Pisinger C, and Døssing M.  A systematic review of health effects of electronic cigarettes, Preventive Medicine. 2014; 69: 248 – 260, ISSN 0091-7435. [cited 2019 May 10].  Available from:
  6. Seitz CM, and Zubair K.  Burn injuries caused by e-cigarette explosions:  A systematic review of published cases.  Tobacco Prevention and Cessation.  2018; 4:  32.  [cited 2019 May 9].  Available from:
  7. Tobacco (Smoking Control) Act (Cap. 315).  Products and Smoking Devices (Simulating Cigarettes or Tobacco) (Control) Regulations, 2010.  L.N. 22 of 2010.  [cited 2019 May 28].  Available from:
  8. Directive 2014/40/EU Of The European Parliament And Of The Council of 3 April 2014 on the approximation of the laws, regulations and administrative provisions of the Member States concerning the manufacture, presentation and sale of tobacco and related products and repealing Directive 2001/37/EC (OJ L 127, 29.4.2014, p. 1)
  9. Tigova O., Castellano Y., Fu M., Agar T., Fong G. T., Quah A. C. et al. Use of e-cigarettes and second-hand exposure to their aerosols in Europe: findings from the ITC 6 European country survey (EUREST-PLUS project). Tobacco Prevention & Cessation. 2018;4(Supplement):A82. doi:10.18332/tpc/90691.
  10. Offermann FJ.  Chemical emissions from e-cigarettes: Direct and indirect (passive) exposures.  Building and Environment. 2015;93(Part 1): 1, 101-105.  [cited 2019 May 27].  Available from:
  11. Tzortzi A., Teloniatis S., Mattiampa G., Bakellas G., Vyzikidou V., Tzavara C. et al. Passive exposure to e-cigarette emissions: irritation symptoms, severity and duration. Tobacco Induced Diseases. 2018;16(1):257. doi:10.18332/tid/84038.
  12. Oh AY, and Kacker A.  Do Electronic Cigarettes Impart a Lower Potential Disease Burden Than Conventional Tobacco Cigarettes?:  Review on E-Cigarette Vapor Versus Tobacco Smoke.  Laryngoscope.  2014; 124:  2702 – 2706.
  13. Britton J, Arnott D, McNeill A, Hopkinson N.  Nicotine without smoke—putting electronic cigarettes in context. British Medical Journal. 2016; i1745.
  14. Jackson S, Kotz D, West R, and Brown J.  Moderators of real-world effectiveness of smoking cessation aids: a population study.  Addiction.  2019.  [cited 2019 May 23].  Available from:
  15. McNeill A, Brose LS, Calder R, Bauld L & Robson D.  Evidence review of ecigarettes and heated tobacco products 2018. A report commissioned by Public Health England. London: Public Health England.
  16. Hajek, P, Phillips-Waller A, Przulj D, Pesolaa F, Myers Smith K, Bisal N, Li J, Parrott, S, Sasieni P, Dawkins L, Maciej Goniewicz LR, and McRobbie HJ.  A Randomized Trial of E-Cigarettes versus Nicotine-Replacement Therapy.  The New England Journal of Medicine. 2019.  [cited 2019 February 12].  Available from:
  17. Dai H, and Leventhal AM.  Association of electronic cigarette vaping and subsequent smoking relapse among former smokers.  Drug and Alcohol Dependence.  2019 [cited 2019 April 30]; 199:  10 – 17.  ISSN 0376-8716.  Available from:
  18. Soneji S, Barrington-Trimis JL, Wills TA, et al. Association Between Initial Use of e-Cigarettes and Subsequent Cigarette Smoking Among Adolescents and Young Adults: A Systematic Review and Meta-analysis. JAMA Pediatrics. 2017; 171 (8): 788 – 797. doi:10.1001/jamapediatrics.2017.1488
  19. Chivers E, Janka M, Franklin P, Mullins B, Larcombe A.  Nicotine and other potentially harmful compounds in “nicotine-free” e-cigarette liquids in Australia.  The Medical Journal of Australia.  2019; 210 (3): 127-128.  doi: 10.5694/mja2.12059 
  20. Cahill  K, Stevens  S, Perera  R, Lancaster  T. Pharmacological interventions for smoking cessation: an overview and network meta‐analysis. Cochrane Database of Systematic Reviews 2013, Issue 5. Art. No.: CD009329. DOI: 10.1002/14651858.CD009329.pub2.
  21. Stead  LF, Koilpillai  P, Fanshawe  TR, Lancaster  T. Combined pharmacotherapy and behavioural interventions for smoking cessation. Cochrane Database of Systematic Reviews 2016, Issue 3. Art. No.: CD008286. DOI: 10.1002/14651858.CD008286.pub3.

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