What are the health risks of using e-cigarettes?
According to WHO’s 2014 report, “Electronic nicotine delivery systems”, the main health risks from e-cigarette use come from the inhaling of nicotine and other toxic emissions from these products, either directly or second-hand.
- Nicotine is the addictive component of tobacco. It can have adverse effects during pregnancy and may contribute to cardiovascular diseases. Although nicotine itself is not a carcinogen, it may function as a tumour promoter. Nicotine seems to be involved in fundamental aspects of the biology of malignant diseases, as well as of neurodegeneration. In addition, fetal and adolescent nicotine exposure can have long-term consequences for brain development. In addition to inhalation, the main health risk from nicotine exposure is overdose 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.
- Although e-cigarettes are likely to be less toxic than conventional cigarettes, they produce more than just water vapour. They contain some cancer-causing agents, such as formaldehyde, which in some brands reach concentrations close to those of some conventional cigarettes. E-cigarettes’ impact on health has not yet been determined.
- Finally, the use of e-cigarettes increases the level of nicotine and particulate matter (PM) in the air. There is no safe level of exposure to PM for bystanders, and the health risk multiplies with increasing concentrations.
In summary, the existing evidence shows that e-cigarette use poses serious threats to adolescents and fetuses, and increases exposure of nonsmokers and bystanders to nicotine and a number of toxicants. 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 for the smokers 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 nonsmokers. They may promote delaying of quitting smoking, or deter quitting.
Does WHO say e-cigarettes are helpful or harmful?
Sufficient evidence shows that e-cigarettes are hazardous to young people, pregnant women and people who do not use nicotine. At the same time, e-cigarettes 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 latter would mean that e-cigarettes would have to be relatively effective as a quitting aid, which there is not yet enough evidence to prove.
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 now the evidence is inconclusive. Given the uncertainty about e-cigarettes’ safety and effectiveness as an aid to quitting, rigorous study is needed by independent research organizations that are not affiliated with the e-cigarette or tobacco industry. In coming years, a solid body of evidence is expected to be built that will allow a definitive conclusion to be drawn.
At present, no governmental agency has yet evaluated and approved an e-cigarette product for smoking cessation, although the United Kingdom’s Medicines and Healthcare Products Regulatory Agency is reviewing some products.
Before considering e-cigarettes as a potential cessation aid, smokers should be encouraged to use a combination of already approved treatments. Nevertheless, experts suggest that appropriately regulated e-cigarettes may have a role to play in supporting some smokers who have failed cessation treatment, been intolerant to it or have refused to use conventional medication.