1. Prevalence and Context of Use in the United States 🇺🇸
In 2021, about 4.5% of American adults used ENDS (Electronic Nicotine Delivery Systems), with more than 11% among 18–24 year-olds; 61% of these young vapers had never smoked conventional cigarettes (Wikipedia, PMC).Among adolescents, more than 3 million middle and high school students reported using e-cigarettes, often on a daily basis (lung.org).
2. Toxic Components of E-Cigarettes
Propylene glycol, vegetable glycerin, and heated flavorings produce aldehydes (formaldehyde, acrolein, etc.), sometimes at higher concentrations than cigarettes if the device overheats (Wikipedia).Recent disposable products have shown high levels of heavy metals (lead, nickel, antimony), in some cases exceeding those found in conventional cigarettes (people.com).
3. Respiratory Effects
E-cigarette use is associated with an increased risk of respiratory diseases: COPD, chronic bronchitis, and asthma (odds ratio between 1.31 and 2.58). The risk increases for dual users (smoking + vaping) (MDPI).Johns Hopkins studies on nearly 250,000 adults over 4 years found a significant association between exclusive e-cigarette use and COPD incidence, as well as a slight hypertension risk among adults aged 30–70 (Hopkins).
4. Cardiovascular Effects
NIH/NHLBI research shows that blood from e-cigarette users causes endothelial dysfunction, reduced nitric oxide, and increased vessel permeability (even more marked than in conventional smokers) (NHLBI).The American Heart Association reports that in healthy young adults, pod-based devices have immediate and lasting negative effects on vascular function (AHA).
A systematic review concludes that chronic use leads to arterial stiffness, oxidative stress, and endothelial dysfunction, with increased risk of myocardial infarction (OR ≈ 1.79 for regular users), thrombosis, and cardiovascular disease (MDPI).
5. Immune, Oral, and Neurological Effects
E-cigarette use causes oral inflammation, alters the microbiome, increases permeability to pathogens, and favors cavities and gum disease (BMC Public Health, PMC).Symptoms of depression, anxiety, or stress appear more frequent among young vapers (up to 60% vs. 40% for non-vapers) (Wikipedia).
Prenatal exposure is linked to increased risk of premature birth, low birth weight, and respiratory and neurological disorders in newborns (MDPI).
6. Specific Concerns Among Youth
E-cigarettes are a gateway to traditional smoking among youth: the National Academies conclude there is “substantial evidence” of this link (lung.org).Animal studies show that flavors, even without nicotine (e.g., vanilla), can trigger addictive behaviors through dopaminergic circuits in adolescents (Wikipedia).
Frequent vaping leads to high urinary levels of lead and uranium, both potentially neurotoxic (The Times).
7. E-Cigarettes as a Harm Reduction Tool
Randomized clinical trials show e-cigarettes can be more effective than nicotine patches or gums in helping people quit smoking (Vox).One estimate attributes 677,000 life-years saved in the U.S. between 2011 and 2019 to e-cigarettes (Vox).
However, discrepancies between clinical trials and population-based observational studies suggest that real-world benefits are less clear (MDPI).
8. Regulatory and Environmental Concerns
The wide diversity and variable reliability of products, as well as youth-targeted flavors, make it necessary to implement stricter regulations to prevent initiation among non-smokers while preserving access for smokers seeking to quit (Vox, AP News).From an environmental perspective, disposable vapes create massive electronic waste (plastic, lithium batteries) that is difficult to recycle, contributing to pollution and resource depletion (Wikipedia).
9. Recommendations
For adult smokers unable to quit by other means: switching to e-cigarettes under control may reduce some risks, but complete cessation remains ideal.For non-smoking youth and pregnant women: all exposure is strongly discouraged — e-cigarettes are not safe.
Public health policies: restrict appealing flavors, ban youth-oriented advertising, enforce strict manufacturing and recycling standards, and promote certified cessation programs (medications, therapy).
10. Scientific Outlook and Future Needs
Long-term longitudinal studies are needed to assess lifetime risks (cancers, cardiovascular diseases, neurodegenerative disorders).Better understanding is required of the effects of different flavors, devices (disposables vs. refillable), and specific populations (youth, pregnant women, vulnerable groups).
Conclusion
Evidence from the United States shows that e-cigarettes carry respiratory, cardiovascular, neurological, and immune risks, particularly for youth, non-smokers, and pregnant women. They may, however, be a harm reduction tool for some adult smokers if used as a step toward complete cessation. Balancing these aspects requires strict regulation, careful use, and support for proven cessation methods.