The invisible threat of thirdhand smoke

You likely know about the health risks associated with smoking, probably even secondhand smoke, but have you heard of thirdhand smoke? The threat of thirdhand smoke is very similar to that of secondhand smoke, with increased risk of heart disease, stroke, respiratory disease and lung cancer.

Thirdhand smoke is smoke residue that remains in the indoor environment, according to Wendy Hughes, a registered respiratory therapist with Texas A&M Health who is currently studying the effects of tobacco use and health impacts related to the substance. This residue reacts with the air to create additional pollutants and then re-emits on some surfaces in your home, car and clothing. Once the residue is in an area, it can continue circulating, so it could reattach to other surfaces like new furniture, wall décor, skin and even hair.

The residue often takes up residence deep within surfaces, contaminating sheet rock, subflooring and other deep elements of buildings that are often only seen during renovation. Hughes cautioned that no amount of dusting, mopping, wiping down and airing out will get rid of the residue.

The trait that separates secondhand smoke and thirdhand smoke is that it is not always obvious when you are being exposed. Secondhand smoke is typically accompanied by a strong odor. However, because thirdhand smoke can linger deep in surfaces for years—even decades—you can’t always smell it.

The good news, Hughes said, is places like hotel rooms, Airbnbs and other short-term rental situations are not likely to affect your health with only a few days of exposure. Longer exposure, however, could lead to negative impacts and the potential of unknowingly bringing the residue with you out into the world.

While the effects of thirdhand smoke can lead to increased risk in adults, it is particularly harmful in children and other vulnerable populations. Research has shown that children who have been exposed to thirdhand smoke have higher rates of childhood asthma and other comorbidities.

Hughes said the best way to mitigate thirdhand smoke exposure and its effects is to avoid places you know have been exposed to tobacco, when possible, and ensure you are in otherwise good health to prevent comorbidities. If you have friends or loved ones who utilize tobacco products, ask them to step outside while using to minimize secondhand or thirdhand exposure.

The most important step, she said, is education about the topic and awareness of risks.

“There’s not a lot of people who are aware of thirdhand smoke risks,” Hughes said. “We need to add to warnings on tobacco packaging to include thirdhand smoke exposure and inform public occupation facilities like hotels and motels.”

She also advocates for more widespread tobacco-free public spaces, such as the ordinance in Victoria, Texas—where Hughes lives and works—and other cities across the state.

“If people want to smoke here they have to go outside, even at a bar, if it is inside city limits,” she said. “I’d like to see more health ordinances like that from public health departments or county departments. Ideally, I would also love to see statewide or even nationwide bans, and I think we should continue to advocate for that from officials.”

By Lasha Markham, Texas A&M Health

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