People exposed to secondhand vapes at home were likelier to report bronchitic symptoms and shortness of breath. This association remained after controlling for personal vaping, smoking, and coexposures. E-cigarettes heat liquids such as propylene glycol and vegetable glycerin to form aerosols that can be inhaled. These chemicals can release harmful toxins, including formaldehyde, acrolein and diacetyl, that may irritate the lungs.
Exposure to Nicotine
The chemicals in secondhand vape aerosol include nicotine, which is absorbed through the lungs and can damage blood vessels. It also contains flavorings, including diacetyl, which can be toxic to the lungs. There are also heavy metals, such as nickel and tin, which can harm the nervous system. And there are ultrafine particles that can irritate the nose and throat. Unlike tobacco smoke, which dissipates quickly, the aerosol in vape vapor can linger indoors and increase its concentration up to 3.6 meters from where the smoker is located. It can even mix with household and office surfaces to create toxic compounds, such as nitrosamines, that are carcinogenic.
Researchers analyzed data from 2097 participants in the Southern California Children’s Health Study who reported secondhand vape exposure and respiratory symptoms (bronchitic symptoms, wheezing and shortness of breath) in at least two survey waves between 2014 and 2019. They controlled for other relevant variables, such as primary smoking or vaping, age, gender, race/ethnicity, parental education and other sociodemographic characteristics. The study found that secondhand vape exposure was associated with increased bronchitic symptoms, wheezing and shorter periods of breath. According to the study’s lead author, these effects are similar to those of secondhand cigarette smoke and should prompt more places to ban vaping and smoking in public.
Exposure to Toxins
The vapor exhaled by vapers contains harmful chemicals that are not only irritating but can also be toxic to the lungs. The vapor’s ingredients include propylene glycol, vegetable glycerin, formaldehyde and acrolein. These substances irritate the lungs and can contribute to asthma, lung damage, respiratory tract disease, and cancer. Other toxins that may be found in secondhand vape smoke include volatile organic compounds, metals and phthalates. These compounds cause respiratory problems, including coughing, wheezing and difficulty breathing. Some toxins can even be absorbed through the skin, which can be particularly dangerous for children. Exposure to toxins can negatively impact the brain and mood. Certain toxins, like nicotine, can also interfere with learning and memory. Other toxins, such as those from formaldehyde, can lead to cancer, respiratory illness and heart disease.
Another concern about secondhand vape smoke is the potential risk for third-hand exposure. What’s not inhaled is left on surfaces such as tables and floors, where someone touching the residue can ingest or absorb it. It can be particularly problematic for young children who often crawl, explore with their hands and put items in their mouths. Nuts in flavored vaping fluids can also trigger allergic reactions in sensitive children. It is why it’s important to keep children away from areas where people are smoking or vaping.
Even though e-cigarettes don’t produce smoke, they still contain toxins that can affect lung health. Researchers have discovered that heavy metals, including nickel, lead, and tin, as well as propylene glycol, acetone, and diethylene glycol contained in vape aerosol, can have similar effects on the respiratory system as secondhand smoke from tobacco cigarettes. Researchers tracked lung health in 2090 high school students over six years starting in 2014. They surveyed participants annually about whether they had experienced symptoms such as bronchitis, daily cough, phlegm or shortness of breath. Exposure to secondhand vape was associated with an increased risk of these symptoms, even after controlling for active vaping and smoking.
In addition to nicotine, vapes are also used to deliver other chemicals, such as glycerol and flavorings, including diacetyl, which can harm the respiratory tract. Chemical pneumonitis, a disorder marked by lung inflammation, can result from exposure to certain substances. What’s not inhaled is left behind on surfaces like floors and furniture, where it can be ingested or inhaled by children who may use their hands to explore the surface and then put their mouths in them or by pets who might lick it. These so-called third-hand exposures can be just as dangerous to lung health as the direct inhalation of nicotine vapor or its residue, and it might be a good reason to keep smokers away from the homes and cars of non-smokers and children.
Who’s at Risk?
The vapor from e-cigarettes, which contains nicotine and other chemicals, can remain in the air for a while. It may stick to indoor surfaces and increase in concentrations up to 3.6 meters away from the source, according to a 2021 study. Ventilation, filtration and other air cleaning techniques can help remove some harmful compounds from indoor environments, but they cannot eliminate them. Vapor can enter the lungs and bloodstream, causing health concerns like secondhand smoke. The flavorings in e-liquids can also cause harm when inhaled. Some of these include volatile aldehydes and oxidant metals, which have been linked to lung disease in smokers. It’s also possible that some children can experience negative impacts from exposure to vapor. Babies and young children can be particularly affected by ingesting or breathing in the aerosol residue collected on surfaces and in their hair, which may contain tobacco-specific nitrosamines, a carcinogen. This type of third-hand exposure is known as an endocrine disruptor, and it can impact young children’s brain and lung development. Vaping is still relatively new, so it may be a while before we understand how long-term exposure to vape vapor can affect people’s health. However, we know that non-vapers exposed to it have increased risks of bronchitic symptoms and shortness of breath.