From the Guidelines
Second-hand smoke from vaping is considered less harmful than second-hand smoke from cigarettes, but it is not completely harmless and can still pose health risks, particularly for vulnerable populations such as children, pregnant women, and people with respiratory conditions. The main components of e-cigarette vapor are propylene glycol, vegetable glycerin, flavorings, and nicotine, though the concentration of these substances in second-hand vapor is significantly lower than what the user inhales 1. Additionally, e-cigarette vapor dissipates more quickly than tobacco smoke and doesn't produce the lingering residue known as thirdhand smoke. However, e-cigarette vapor can still contain harmful substances including nicotine, ultrafine particles, heavy metals like lead and tin, and volatile organic compounds, as found in a study published in Pediatrics in 2015 1.
Some key points to consider:
- E-cigarette aerosol contains toxic and carcinogenic substances in addition to nicotine, as found in a laboratory study of indoor air quality after indoor e-cigarette use by volunteers 1.
- Second-hand smoke exposure is known to cause cardiovascular disease and stroke in nonsmokers, and it can lead to immediate adverse events, as stated in the 2019 ACC/AHA guideline on the primary prevention of cardiovascular disease 1.
- There is no safe lower limit of exposure to second-hand smoke, and even brief exposure can trigger an MI, as noted in the same guideline 1.
- Clinicians are recommended to advise patients to take precautions against exposure to second-hand smoke and aerosol from all tobacco products, including e-cigarettes, by instituting smoking restrictions inside all homes and vehicles and within 25 feet from all entryways, windows, and building vents 1.
Overall, while second-hand smoke from vaping may be considered less harmful than second-hand smoke from cigarettes, it is still important to take precautions to minimize exposure, particularly for vulnerable populations. Avoiding exposure to either second-hand smoke from cigarettes or e-cigarettes is the safest approach, as current evidence suggests that both can pose health risks, although the risks associated with e-cigarettes may be lower 1.
From the Research
Comparison of Second-Hand Smoke from Vaping and Cigarettes
- Second-hand smoke from electronic cigarettes (e-cigarettes) is a concern due to the potential health risks it poses to non-smokers, particularly children 2, 3.
- Studies have shown that e-cigarettes emit pollutants, including propylene glycol, glycerol, nicotine, and aerosol particulates, which can be inhaled by bystanders 4, 5.
- The concentration of airborne nicotine in homes with e-cigarette users is lower than in homes with conventional cigarette smokers, but still poses a risk to non-smokers 5.
- The incremental lifetime cancer risk (ILCR) from e-cigarettes is lower than that from cigarettes, but still poses a potential carcinogenic risk, particularly through air-to-skin transdermal exposure to third-hand smoke 2.
- Active and passive smoking of cigarettes, electronic nicotine delivery systems, and tobacco heating products can induce oxidative stress and inflammatory response in the airways, which is a key risk factor for chronic obstructive pulmonary disease (COPD) development 6.
Health Risks of Second-Hand Smoke from Vaping
- Children are more vulnerable to the health risks of second-hand smoke from vaping due to their higher per body weight daily intake of pollutants 2.
- Non-smokers exposed to e-cigarette vapor at home can absorb nicotine, as evidenced by higher salivary cotinine concentrations compared to non-smokers from control homes 5.
- The health effects of long-term exposure to second-hand smoke from vaping are not yet fully understood and require further research 4, 6.
- Reducing health risks from exposure to second-hand smoke from vaping and conventional cigarettes requires rigorous enforcement of smoking-free policies and increased awareness of the risks associated with environmental tobacco smoke 2, 3.