Third-Hand Smoke

Caroline Halsted and Alex Pew, National Center for Health Research

The dangers of smoking tobacco and exposure to second-hand smoke are well-known, but did you know that third-hand smoke can also cause serious health problems?

People can be exposed to second-hand smoke any time they are around someone who is smoking a cigarette. It comes from both the smoke from the tip of the cigarette and the smoke that the smoker is exhaling.[1] Second-hand smoke causes about 600,000 premature deaths every year worldwide.

The idea of third-hand smoke was first introduced as a health hazard in 2006. Third-hand smoke (THS) is the tobacco residue that can remain on surfaces and dust for months after someone smokes a cigarette.[2] In some situations, third-hand smoke can even remain on fabric for a year and a half after the last exposure to cigarette smoke.[3] This residue can lead to respiratory issues like coughing, asthma, and respiratory tract infections.[4] Third-hand smoke most often sticks around on indoor surfaces. Even in seemingly tobacco-free places, tobacco residue can remain on walls, floors, furniture, clothing, and even hair for months after a cigarette is smoked.[5] A study investigating the effects of short-term third-hand smoke found that exposed mice were more likely to develop lung cancer compared with mice that were not exposed to THS.[6]

Exposure usually occurs through skin contact. When someone touches a surface that has smoke residue on it, that residue ends up on their hands which poses risks when they touch their face or mouth. Non-smokers living in homes that were inhabited by smokers previously often have residue left on their hands.[5] A longitudinal study looking at second-hand and third-hand smoke in a casino found extremely high levels of residue on surfaces and in dust. After a one-month smoking ban, surface nicotine decreased by 90% but nicotine and tobacco-specific cancer-causing chemicals in dust decreased more slowly, declining by 90% only after 3 months.[7]

Health Risks for Children

Because of the way people are most often exposed to third-hand smoke, children are particularly vulnerable. Children often crawl and play on the floor and furniture, and frequently make hand-to-mouth contact or put their mouths on household objects. Even so, many parents aren’t aware of the dangers of environmental tobacco smoke.

The Bottom Line

Parents should know that if they smoke in the car, their children can absorb the dangerous chemicals from the car upholstery, even if the child wasn’t inside at the time of the smoking. The same is true for smoking inside of the home. The more parents are aware of this issue, the less childhood exposure there will be. The American Academy of Pediatrics emphasizes that quitting smoking is the only way to ensure that your child is not exposed to third-hand smoke.[8] Make sure your friends aware of the dangers of third-hand smoke, and make sure you and your family avoid areas with possible environmental tobacco exposure. Smoking outside decreases exposure to third-hand smoke, but friends and family members will still be exposed to THS on the skin, hair, and clothes of smokers.

Thoroughly cleaning your home, washing or dry cleaning clothing, and vacuuming your car and help remove dangerous chemicals that are left over after smoking. If you are working towards quitting or have already quit, it may be best to thoroughly clean fabrics in order to reduce you and your family’s risk of exposure even further.[3]


  1. WHO Second-Hand Smoke Fact Sheet. (2014). Retrieved from;jsessionid=B949B1149C3A9733546F4821608D9DE7?sequence=1
  2. Acuff, L., Fristoe, K., Hamblen, J., Smith, M., & Chen, J. (2015). Third-Hand Smoke: Old Smoke, New Concerns. Journal of Community Health, 41(3), 680-687. doi:10.1007/s10900-015-0114-1
  3. Bahl, V., Jacob, P., Havel, C., Schick, S. F., & Talbot, P. (2014). Thirdhand Cigarette Smoke: Factors Affecting Exposure and Remediation. PLoS ONE, 9(10). doi:10.1371/journal.pone.0108258
  4. Roberts, C., Wagler, G., & Carr, M. M. (2017). Environmental Tobacco Smoke: Public Perception of Risks of Exposing Children to Second- and Third-Hand Tobacco Smoke. Journal of Pediatric Health Care, 31(1). doi:10.1016/j.pedhc.2016.08.008
  5. Ganjre, A. P., & Sarode, G. S. (2016). Third hand smoke – A hidden demon. Oral Oncology, 54. doi:10.1016/j.oraloncology.2016.01.007
  6. Hang B, Wang Y, Jen K, et al. Short-term early exposure to thirdhand cigarette smoke increases lung cancer incidence in mice. Clinical Science [serial online]. n.d.;132(4):475-488. Available from: Science Citation Index, Ipswich, MA. Accessed May 21, 2018.
  7. Matt GE, Quintana PJE, Hoh E, et al A Casino goes smoke free: a longitudinal study of secondhand and thirdhand smoke pollution and exposure Tobacco Control Published Online First: 08 February 2018. doi: 10.1136/tobaccocontrol-2017-054052
  8. How Parents Can Prevent Exposure to Thirdhand Smoke. Accessed May 21, 2018.