E-cigarettes, or vapes, are causing harm and risk introducing a new generation to smoking, warn experts from The Australian National University (ANU) following their government report into vaping.
According to the significant review, using nicotine e-cigarettes increases the risk of various adverse health outcomes, especially in youth, including taking up smoking, addiction, poisoning, seizures, burns, and lung injury.
The report aims to provide a systematic overview of the contemporary evidence on the health effects of nicotine and non-nicotine e-cigarette use, excluding, where possible use of tetrahydrocannabinol (THC) and other illicit substances.
Report: Health impacts of electronic cigarettes. Image Credit: FOTOGRIN / Shutterstock
E-cigarettes were first manufactured in 2003 and became popular between 2006 and 2007. E-cigarettes or "vapes" are devices that aerosolize a liquid (e-liquid) for inhalation. Standard e-liquids include propylene glycol, vegetable glycerine, and water and might also contain flavorings and nicotine. Many countries currently ban the sale of nicotine e-cigarettes, while Australia allows their sale while regulating them either partially or fully. Several independent reviews are available that explored and provided evidence on the impact of e-cigarettes on health. Nevertheless, no systemic review is available on the health effects of e-cigarettes.
The current review was commissioned by the Australian Department of Health and was conducted by the National Centre for Epidemiology and Population Health. This systemic review included all relevant information obtained from primary research studies and major international reviews.
Professor Emily Banks from the ANU National Centre for Epidemiology and Population Health, the lead author of this review, stated, "We reviewed the global evidence in order to support informed choices on vaping for Australia."
The systematic umbrella and top-up review identified 18,992 potentially eligible studies; 12,434 duplicates were removed, and 6,558 underwent title and abstract screening.
There were 227 identified in the systematic literature database search, 10 from forward and backward searching, and one from grey literature consistent with the inclusion criteria on health outcomes associated with e-cigarette use.
Of these 238 studies, 152 were included in the evidence synthesis, and 86 were excluded from the evidence synthesis as they were rated as not providing evidence suitable for assessing the causal relationship between e-cigarette use and the outcome specified. In addition to the 152 studies, 37 from the two previous reviews on smoking uptake and cessation were included in the evidence synthesis. Therefore, a total of 189 studies were included in the evidence synthesis.
Although nicotine delivery data from e-cigarettes is generally not reported, nicotine e-cigarettes are the most commonly used. Therefore, health effects observed with nicotine e-cigarettes were assumed to apply unless otherwise stated.
In terms of e-cigarette health impacts, there is minimal evidence. However, based on evidence from around the world, nicotine e-cigarette use is associated with a number of adverse health outcomes. E-cigarettes and their constituents have been shown to cause poisoning, burns, and immediate toxicity through inhalation, including seizures. In addition to causing addiction, they can cause less serious adverse events, such as throat irritation and nausea, that are less serious.
Evidence shows that e-cigarettes cause acute lung injury, with e-liquid containing THC and vitamin E acetate primarily responsible. However, 1 in 8 cases reported in the most comprehensive study to date involved nicotine-only products.
Among their environmental impacts are waste, fires, and indoor particulate matter, all of which, in turn, have adverse health effects.
Insufficient evidence exists to support the claim that smoking cessation and switching to e-cigarettes will cause an exacerbation of respiratory disease or a change in lung function or other respiratory measures as a result of the cessation of smoking. In addition, the evidence for e-cigarettes reducing lung function in non-smokers is limited.
Among smokers, there is moderate evidence that using e-cigarettes increases heart rate, systolic blood pressure, diastolic blood pressure, and arterial stiffness acutely after use.
Using e-cigarettes results in inhaling many complex chemicals; previous research has identified 243 unique chemicals. Out of these, one was not permitted in e-liquids, and thirty-eight were listed as poisons. In addition, a total of twenty-seven chemical reaction products were detected. These included carbonyls, such as acetone, acetaldehyde, and acrolein, i.e., products associated with harmful health outcomes in humans.
The growing use of e-cigarettes by non-smokers, especially among the youth, represents a serious public health risk. This is owing to the existing evidence that e-cigarette use generates new tobacco smokers – with well-documented elevated levels of harm. Ex-smokers are likely to see more considerable gains in overall health if they avoid the use of e-cigarettes, and this also reduces the risk of resumption of smoking.
It is common in many countries, including Australia, for people to smoke tobacco and use e-cigarettes simultaneously. The direct health risks of this are unclear, but smokers are more prone to the documented adverse health consequences of e-cigarettes. Besides the adverse effects on the smokers themselves, risks such as environmental impact and poisoning are felt by family members and the wider community.
It could well be that e-cigarettes are beneficial for smokers who use them to quit smoking altogether, given the extreme harm that smoking can cause. However, the counter-argument is that most quitters quit smoking unaided, and there is limited evidence of efficacy for smoking cessation. Therefore, the risks remain substantial, and the costs far outweigh the uncertain benefits. This is consistent with the fact that e-cigarettes are not registered as therapeutic goods internationally, and their safety/quality parameters have not been established.
The identified risks of e-cigarettes could increase due to a range of factors. These include adulteration, inadequate or inaccurate labeling, flavorings, high-concentration nicotine salt products, and non-child-resistant packaging. Additionally, low cost, advertising, ease of availability, and lack of legislation enforcement could lead to higher nicotine e-cigarette use in the broader community.
It is well documented that nicotine e-cigarettes can be harmful to health. The current global evidence proves that using nicotine e-cigarettes increases the chances of poisoning, addiction, smoking uptake in youth, and lung injury. The effects on clinical outcomes related to cancer, respiratory conditions, cardiovascular disease, and mental health are unknown. Besides the direct effects on the e-cigarette user, adverse environmental impacts include fires, waste, and pollution. Based on current evidence, it is best to avoid e-cigarette use, particularly by non-smokers and young individuals.