The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

There are many sources of air pollution, such as car and factory emissions. Tobacco smoke pollution, however, has an easier solution to reduce exposure than many other forms of air pollution. People may be more willing to make changes to reduce tobacco pollution, such as not smoking around others, than to make changes to reduce car emissions, such as not driving their cars. In addition, some chemicals in thirdhand smoke are only found in tobacco smoke, which means tobacco smoke is adding new cancer-causing chemicals to additional air pollution. To protect public health, we have to work to avoid thirdhand tobacco smoke exposure.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

There are many pollutants that can contaminate our environments, such as vehicle emissions and industrial air pollutants. Policymakers and the public often focus on these types of pollutants. However, there remain a lot of other forms of pollution to consider, such as pollutants from tobacco smoke. Addressing tobacco smoke pollution highlights a preventable cause of harm, in this case smoking, that can be changed or eliminated to keep the environment clean and healthy. For example, it is much more reasonable to ask someone not to smoke around others than it is to ask someone not to drive a vehicle.

In addition, some of the toxic and cancer-causing chemicals in thirdhand smoke are only found in tobacco smoke. This means that thirdhand smoke adds a unique mixture of harmful substances to the ones already created by pollution from cars and factories. To prevent exposure to these additional pollutants, individuals should never allow smoking indoors or near a doorway or window.

Eliminating exposure to toxic pollutants is important for protecting human health. This means addressing many forms of air pollution, including tobacco smoke residue.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: December 2024

Sources:

Jacob P 3rd, Benowitz NL, Destaillats H, Gundel L, Hang B, Martins-Green M, Matt GE, Quintana PJ, Samet JM, Schick SF, Talbot P, Aquilina NJ, Hovell MF, Mao JH, Whitehead TP. Thirdhand Smoke: New Evidence, Challenges, and Future Directions. Chem Res Toxicol. 2017 Jan 17;30(1):270-294. doi: 10.1021/acs.chemrestox.6b00343.

Whitehead TP, Havel C, Metayer C, Benowitz NL, and Jacob 3rd P. Tobacco alkaloids and tobacco-specific nitrosamines in dust from homes of smokeless tobacco users, active smokers and nontobacco users. Chem Res Toxicol. 2015;28(5):1007-14.

Schick SF, Farraro KF, Perrino C, Sleiman M, van de Vossenberg G, Trinh MP, Hammond SK, Jenkins BM, Balmes J. Thirdhand cigarette smoke in an experimental chamber: evidence of surface deposition of nicotine, nitrosamines and polycyclic aromatic hydrocarbons and de novo formation of NNK. Tob Control. 2014;23(2):152-9.