Moving into a smoker’s home? Consider replacing the carpet.

Moving into a smoker's home? Consider replacing the carpet.

The Lingering Dangers of Thirdhand Smoke: Why Removing Old Carpeting Should Be Your First Step

By Cara Murez HealthDay Reporter

If you’re moving into a home where smokers lived, the first thing you should do to protect your lungs is rip out any old carpeting, new research suggests. Scientists found that tobacco smoke clings to carpet fibers long after smoking has stopped, and ozone generators that purify the air and surfaces can’t remove it completely.

This leftover residue, also known as “thirdhand smoke,” can pollute indoor spaces for an extended period of time, according to investigators from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory in Berkeley, Calif.

The Perils of Thirdhand Smoke:

Thirdhand smoke refers to the remnants of tobacco smoke that settle on surfaces and reenter the air, posing potential health risks. It turns out that the presence of thirdhand smoke goes beyond merely an unpleasant odor. Researchers have discovered that it can transform into new types of contaminants, compounding the health hazards.

In a study conducted by the Berkeley Lab, researchers gathered old smoke-contaminated carpet from homes in the San Diego area, along with new carpet exposed to fresh smoke in the lab. They discovered that while ozone generators were partially effective in removing a group of compounds named polycyclic aromatic hydrocarbons from both types of carpet samples, they were relatively ineffective when it came to deeply embedded nicotine. The researchers explained that ozone generators release ozone gas, which can react with harmful compounds and remove them from the air and surfaces. However, the equipment also creates a burst of contaminants when running, making it a less reliable solution for completely eliminating thirdhand smoke.

The Illusion of Odor Removal:

The use of ozone generators to remove odors can give a false sense of efficacy, according to Berkeley Lab Senior Scientist Hugo Destaillats. He cautions that while ozone generators are commonly employed to remediate fire damage and mold, they have limitations, as confirmed by this study. The lack of a detectable smell does not guarantee the elimination of all the contaminants associated with thirdhand smoke.

Destaillats emphasizes the need for a more comprehensive approach to tackling the issue. The researchers plan to further investigate the role of other indoor pollution reservoirs, such as drywall and upholstery.

The Importance of Replacing Old Carpeting:

Based on these findings, the study’s lead author and researcher, Xiaochen Tang, suggests that replacing old carpeting with new ones may be the best solution. While ozone purification has its uses, it has limited effectiveness in deeply cleaning materials like carpet. The tobacco smoke residue tends to cling to the carpet fibers, making it difficult to completely eradicate using typical household methods.

So, before settling into a new home, especially one that was previously occupied by smokers, it is essential to prioritize the removal of old carpeting. By doing so, you’ll significantly reduce your exposure to thirdhand smoke and minimize potential health risks.


This study sheds light on the lingering dangers of thirdhand smoke and the inefficiency of ozone generators in fully eliminating tobacco smoke residues. It emphasizes the need for proactive measures, such as replacing old carpeting, to reduce the risks associated with thirdhand smoke. The ongoing research by the Berkeley Lab aims to uncover other potential indoor pollution reservoirs, further enhancing our understanding of how to create healthier living environments.

More information:

The U.S. National Institute on Drug Abuse has more on thirdhand smoke.


Lawrence Berkeley National Laboratory, news release, Aug. 9, 2023

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