Figures published in a review by the Royal College of Physicians of Edinburgh (RCPE) suggest that electronic cigarette (e-cigarette) use is on the rise. Around 2.9 million UK adults use e-cigarettes, and the majority appear to do so to stop smoking.
The use of e-cigarettes (also known as vaping) is still a relatively new practice, and uncertainty about its short and long-term effects remains. However, data from Public Health England suggests that e-cigarettes may be 95% safer than traditional cigarettes.
But with San Francisco recently becoming the first major US city to ban the use of e-cigarettes, is this smoking alternative as risk-free as it seems?
What are e-cigarettes?
E-cigarettes are devices that produce vapour, rather than smoke. They do so by heating liquids that typically contain nicotine, flavourings, propylene glycol, and/or vegetable glycerine.
Just like traditional cigarettes, the nicotine found in e-cigarettes is addictive. However, nicotine itself is relatively harmless.
E-cigarettes are often viewed as less harmful to the body than cigarettes because they do not burn tobacco. As such, they do not produce the two most harmful substances found in tobacco smoke: carbon monoxide and tar.
However, the liquid and vapour of e-cigarettes do contain low levels of other potentially harmful chemicals that are also found in cigarette smoke. This suggests that while e-cigarettes are considered safer than traditional cigarettes, they cannot be presumed to be risk-free.
What are the potential risks of using e-cigarettes?
Current data suggests that e-cigarettes may be a low risk alternative to smoking. However, a recent US outbreak of an unknown lung disease that is associated with e-cigarette use has opened up new questions about the safety of these products.
The outbreak, which is thought to be responsible for 380 cases of illness and six deaths so far, has prompted the Centers for Disease Control and Prevention (CDC), the US Food and Drug Administration (FDA), and US state and local health departments to launch an investigation into the lung disease.
But what is already known about the safety of e-cigarettes?
According to The National Institute for Health and Care Excellence (NICE), in-depth scientific evidence into the long-term health impact of e-cigarettes is still developing.
However, some research does exist.
As outlined by the RCPE’s 2018 report, Electronic Cigarettes: A Brief Update, research suggests that smokers who switch to vaping alone may reduce their exposure to more than 70 cancer-causing substances (carcinogens) that exist in tobacco smoke.
Furthermore, a recent paper by Public Health England highlighted a study which suggests that e-cigarette use may carry less than 0.5% of the cancer risk associated with smoking.
Lung disease risk
According to Public Health England, the risk of lung disease from vaping is currently unknown. However, it is likely to be substantially lower than the risk of smoking. Two studies looking at levels of a strong lung irritant called acrolein found that e-cigarette users have similar levels of acrolein as non-smokers.
When a person smokes a cigarette, tiny particles enter the bloodstream where they trigger an inflammatory response that contributes to cardiovascular disease. It is thought that vaping also delivers these particles to the bloodstream, suggesting that vaping may also be linked to CVD.
In support of this theory, the RCPE’s report states that a cross-sectional analysis of US population surveys showed that people who use e-cigarettes on a daily basis had an increased risk of having a heart attack. However, these types of studies don’t prove that e-cigarettes themselves cause heart attacks. Public Health England has reported that the exact risk of CVD from e-cigarettes is unclear, but likely to be significantly lower than the risk of smoking.
Risk from the vapour
Low levels of metals have been identified in e-cigarette vapours, but this remains unassociated with any significant safety concerns.
There is also no clear evidence to suggest that the flavourings used in e-cigarettes may be harmful to the body. However, according to Public Health England’s Evidence review of e-cigarettes and heated tobacco products 2018, inhalation of these flavourings could carry some preventable risks.
Passive vaping risk
While there is strong evidence to show that secondhand smoke from cigarettes is harmful to health, there is nothing to suggest that secondhand e-cigarette vapour can harm others.
Safety during pregnancy
There is a lack of evidence about the safety of e-cigarettes in pregnancy, but it is thought they are likely to be less harmful than cigarettes.
If you are pregnant and trying to stop smoking, the National Health Service (NHS) in England recommends that you use licensed nicotine replacement therapy products, including patches and gum.
E-cigarettes have been reported to explode or catch fire and cause burns or chemical injuries. Research shows that these devices can cause burns when they are being used, or during storage (e.g. in a pocket).
Weighing up the evidence
After reviewing the available evidence on e-cigarettes, the latest guidelines from NICE conclude that ‘e-cigarettes are substantially less harmful to health than smoking but are not risk free’.
Its final recommendation is that people who smoke and want to use a nicotine-containing e-cigarette to quit smoking should stop smoking tobacco completely, because any smoking is harmful.
And while the US investigation into the e-cigarette-related lung disease outbreak is ongoing, the CDC has advised that people concerned about the potential health risks of e-cigarettes should consider not using these devices. If you use them, you should monitor your symptoms and see a health professional if you have any concerns.
The CDC also advises that e-cigarettes should not be used by youth, young adults, pregnant women or adults who do not already use tobacco products.