What is thirdhand smoke, and why is it a concern?
Thirdhand smoke is made up of the pollutants that settle indoors when tobacco is smoked. The chemicals in thirdhand smoke include nicotine as well as cancer-causing substances such as formaldehyde, naphthalene and others.
Thirdhand smoke builds up on surfaces over time. It can become embedded in most soft surfaces such as clothing, furniture, drapes, bedding and carpets. It also settles as dust-like particles on hard surfaces such as walls, floors and in vehicles. Thirdhand smoke can remain for many months even after smoking has stopped.
Thirdhand smoke can't be eliminated by airing out rooms, opening windows, using fans or air conditioners, or confining smoking to only certain areas of a home. Traditional household cleaning often cannot effectively remove thirdhand smoke from many surfaces.
Thirdhand smoke poses a potential health hazard to nonsmokers — especially children. Substances in thirdhand smoke are known to be hazardous to health. People are exposed to the chemicals in thirdhand smoke when they touch contaminated surfaces or breathe in the gases that thirdhand smoke may release.
Infants and young children are at greater risk for exposure to thirdhand smoke than adults due to activities such as crawling and putting non-food items in their mouths. They also tend to spend more time indoors.
Research has clearly shown that secondhand smoke causes many health problems, including cancer, heart disease and respiratory illness. The effects from long-term exposure to the toxins in thirdhand smoke are not as well studied. But research has shown that indoor smoking raises the risk of exposure to harmful chemicals, and that ventilation and cleaning cannot adequately eliminate these hazards.
The only way to protect nonsmokers, especially young children, from the dangers of thirdhand smoke is to remove all forms of smoking from indoor areas, including inside vehicles.
Aug. 02, 2022
From Mayo Clinic to your inbox
Sign up for free, and stay up to date on research advancements, health tips and current health topics, like COVID-19, plus expertise on managing health.
ErrorEmail field is required
ErrorInclude a valid email address
To provide you with the most relevant and helpful information, and understand which
information is beneficial, we may combine your email and website usage information with
other information we have about you. If you are a Mayo Clinic patient, this could
include protected health information. If we combine this information with your protected
health information, we will treat all of that information as protected health
information and will only use or disclose that information as set forth in our notice of
privacy practices. You may opt-out of email communications at any time by clicking on
the unsubscribe link in the e-mail.
Thank you for subscribing!
You'll soon start receiving the latest Mayo Clinic health information you requested in your inbox.
Sorry something went wrong with your subscription
Please, try again in a couple of minutes
See more Expert Answers
- Kelley ST, et al. Altered microbiomes in thirdhand smoke-exposed children and their home environments. Pediatric Research. 2021; doi:10.1038/s41390-021-01400-1.
- Whitlatch AW, et al. Thirdhand smoke at Philip Morris. Nicotine & Tobacco Research. 2019; doi:10.1093/ntr/nty153.
- Samet JM, et al. Control of secondhand smoke exposure. https://www.uptodate.com/contents/search. Accessed July 13, 2022.
- Samet JM, et al. Secondhand smoke exposure: Effects in children. https://www.uptodate.com/contents/search. Accessed July 13, 2022.
- Bahl V, et al. Thirdhand cigarette smoke: Factors affecting exposure and remediation. PloS One. 2014; doi:10.1371/journal.pone.0108258.
- Ventilation does not effectively protect nonsmokers from secondhand smoke. Centers for Disease Control and Prevention. https://www.cdc.gov/tobacco/data_statistics/fact_sheets/secondhand_smoke/protection/ventilation/index.htm. Accessed July 13, 2022.