E-cigarettes are designed to deliver nicotine or other substances to a user as an aerosol rather than burning tobacco. The liquid contains four main ingredients: propylene glycol and/or glycerine as a base for producing the aerosol, flavours and optional nicotine. E-cigarettes contain and deliver varying levels of nicotine, some of which can be similar to levels in cigarettes.

About 500 e-cigarette brands are available today, but only a few have been analysed. Evidence  shows that e-cigarettes’ aerosol usually contains cancer-causing compounds, but at levels 1–2 orders of magnitude lower than those in tobacco smoke. E-cigarettes are therefore likely to be less toxic than conventional cigarettes but the levels of carcinogenic agents in some of the analysed brands are as high as those in the smoke produced by some cigarettes.

According to WHO’s 2014 report, “Electronic nicotine delivery systems”, the main health risks from e-cigarettes come from inhaling the nicotine and other toxic emissions and from overdosing by ingestion or through skin contact. Users fill e-cigarettes’ containers themselves so they, not the manufacturers, set the levels of nicotine. Nicotine poisoning can result from the liquid’s accidentally coming into contact with users’ skin or ingestion by children. The United States and the United Kingdom have already seen a tremendous increase in reported nicotine poisoning, often involving children.

Nevertheless, the reduced exposure to toxicants of well regulated e-cigarettes, used by established adult smokers as a complete substitution for cigarettes, is likely to be less toxic than conventional cigarettes or other combusted tobacco products. The amount of risk reduction, however, is unknown. E-cigarettes may carry a risk of addiction to nicotine and tobacco products among young people and non-smokers. However, they are likely to be less toxic than cigarettes for adult smokers if product content is well regulated and if the smokers use them as a complete substitution for cigarettes.

The inhalation of nicotine by nonsmokers, adolescents and pregnant women not only leads to addiction but has also been linked to some cardiovascular problems in adults. In addition, fetal and adolescent nicotine exposure can have long-term consequences for brain development. As young people account for a growing proportion of e-cigarette users, anti-tobacco experts are concerned that e-cigarette use can serve as a gateway for them to nicotine addiction and ultimately smoking. The literature shows that experimentation with e-cigarettes among adolescents doubled in 2008–2012. One of the presumed reasons for this can be the great variety of flavours of e-cigarettes (up to 8000 are available), including flavours like those of fruit, candy and alcoholic drinks. These could entice young people to experiment with e-cigarettes and then become addicted to nicotine.

For all these reasons, WHO can neither dismiss nor accept the use of e-cigarettes globally without further evidence, and regulation is necessary in the meantime both to protect the public from any potential ill effects and to ensure that these products do not contribute to the tobacco epidemic.

For more information on the WHO report, click here      on www.who.int