Two senior radiologists from Belgium have issued a fresh warning about the potentially harmful effects of electronic cigarettes on health, and they have called for more research into this emerging field.
"Vaping may not be as safe as we assume," noted Prof. Inneke Willekens, PhD, from the department of radiology at University Hospital Brussels (UZ Brussel), and Prof. Johan de Mey, PhD, head of radiology at UZ Brussel. "As vaping is increasing in popularity, there is a need for further investigation of the health effects of electronic cigarettes."
E-cigarettes are devices that produce an aerosol by heating a liquid that contains a solvent (vegetable glycerin, propylene glycol, or a mixture), flavorings, and nicotine, they explained in an e-poster due to be presented at the upcoming congress organized by the European Society of Thoracic Imaging (ESTI) and the Fleischner Society. The meeting begins in Paris on 9 May, but the e-posters are available in advance through the European Society of Radiology's Electronic Presentation Online System (EPOS).
E-cigarette vendors are presenting vaping as being cool and are promoting it aggressively to younger people.In vaping, the evaporation of the liquid at the heating element is followed by rapid cooling to form an aerosol. Epidemiologic data indicate that minors are increasingly using e-cigarettes due to the robust marketing and advertising campaigns of manufacturers, according to Willekens and de Mey.
Hazards of vaping
E-cigarettes may be a useful tool for reducing traditional cigarette smoking, and for long-term smokers, experts speculate that the use of e-cigarettes rather than tobacco cigarettes may be associated with better short- and long-term health outcomes. There are risks, however.
"Two potential hazards related to e-cigarettes are acute toxic effects caused by accidental or intentional ingestion of e-cigarette liquids and physical injury caused by the e-cigarette," they stated. "E-cigarettes both contain and emit a number of potentially toxic substances. The two primary ingredients found in e-cigarettes (propylene glycol and vegetable glycerin) are likely to expose users to a high level of toxins and the more ingredients the user is inhaling, the greater the toxicity."
E-cigarettes produce a number of dangerous chemicals, including acetaldehyde and formaldehyde. Aldehydes in cigarette smoke impair mitochondrial function and reduce ciliary beat frequency, leading to diminished mucociliary clearance, the authors continued. The inhalation of cinnamaldehyde may increase the risk of respiratory infections in e-cigarette users.
E-cigarettes also contain acrolein, a herbicide primarily used to kill weeds, which contributes to the morbidity and mortality associated with acute lung injury and chronic obstructive pulmonary disease (COPD) and possibly asthma and lung cancer. Another popular flavoring, diacetyl, has been associated with the development of bronchiolitis obliterans, or "popcorn lung," when inhaled during manufacturing processes.
Further information on the health effects of e-cigarette use can be gained from case reports, and in their ESTI 2019 exhibit, Willekens and de Mey provide details about these five relevant clinical cases:
- Lipoid pneumonia: CT of the chest demonstrates bilateral central ground-glass and consolidative opacities in the left upper lobe and perihilar right upper lobe.
- Bronchiolitis obliterans: CT demonstrates poorly defined pulmonary nodules with fluffy parenchyma opacification centered along the terminal bronchovascular units.
- Eosinophilic pneumonia with pleural effusion: CT of the chest shows diffuse alveolar infiltration with bilateral pleural effusion.
- Acute hypersensitivity pneumonitis: CT shows homogeneous ground-glass and alveolar opacities that are bilateral and symmetric.
- Diffuse alveolar hemorrhage: CT demonstrates diffuse ground-glass opacification and patchy consolidations.
Targeting younger people
In 2018, the Juul vape device accounted for more than 75% of the U.S. e-cigarette market, and instead of catering to adult smokers, the e-cigarette industry appeared to overwhelmingly target nonsmoking youth, according to a recent article posted by Vox.com.
In the Vox.com article, Maciej Goniewicz, a leading e-cigarette researcher based at Roswell Park Comprehensive Cancer Center in Buffalo, New York, U.S., said he has watched the shift unfold up close: The volunteers who come forward for his e-cigarette studies seem to be getting younger.
"[These are] people who were breathing pure air for a long time -- and have never smoked tobacco cigarettes -- who now have started using e-cigarettes," Goniewicz said.
Global researchers are now trying to figure out how this new habit might affect developing bodies and brains in the long term, and they are finding that e-cigarettes may be more dangerous than appreciated, especially for the heart, lungs, and brain. There's also a growing body of research suggesting that vaping can lead to smoking.
The report from Vox.com listed these four potential side effects:
Vaping may be linked to a heightened risk of seizures.
When you turn on an e-cigarette, you're heating a liquid that contains flavors, other chemicals, and often nicotine. Some devices deliver high doses of nicotine. Seizures can be a side effect of nicotine poisoning.
The nicotine in e-cigarettes may stress the cardiovascular system.
The impact of e-cigarettes on the body's cardiovascular system is an emerging area of research. Recent observational studies have found a link between regular vaping and an increased risk of heart attacks, strokes, and coronary artery disease. The studies don't prove e-cigarettes cause these conditions, but given the known cardiovascular effects of nicotine, there's a lot more to learn about vaping and its effects.
Microscopic particles emitted by e-cigarettes may lead to cardiovascular toxicity.
The heating element in e-cigarettes emits tiny particles, sometimes including metals, which can lodge themselves deep into the lungs and get absorbed into the body's circulatory system. Recent studies show that puffing on e-cigarettes increases the concentration of these microscopic pollutants in indoor environments.
E-cigarette vapor may irritate the lungs.
Recent research on wheezing -- a high-pitched sound caused by narrowed and abnormal airways -- shows that breathing vapor into the lungs can irritate them. Wheezing is more than just an annoyance; it can be a sign of emphysema, heart failure, and lung cancer.
However, this evidence doesn't mean cigarettes are safer than e-cigarettes, Vox.com author Julia Belluz noted.
"In fact, medical experts agree that vaping is far better for health than smoking, one of the deadliest habits known to humankind," she warned.
"What's more, since people haven't been vaping for very long, the science on its health effects is still preliminary -- and far from conclusive. It may take decades for any diseases possibly caused by e-cigarettes to fully surface, particularly in the young, healthy people now using them," she wrote.
