What is thirdhand smoke?

Thirdhand smoke refers to residual exposure via surfaces that have encountered cigarette smoke. You’re likely familiar with secondhand smoke exposure that occurs from inhaling smoke from someone else using cigarettes.

Thirdhand smoke, on the other hand, deals with surfaces you touch that have nicotine residue on them. Such surfaces may include:

  • clothing
  • flooring
  • furniture
  • toys
  • vehicles
  • walls

Contact can also occur when you breathe in some of the lingering gasses left on these surfaces. Thirdhand smoke can be especially toxic if it combines with other indoor pollutants.

While secondhand smoke is as dangerous as smoking cigarettes themselves, thirdhand smoke is gaining attention for its health dangers, too.

Learn more about thirdhand smoke and its effects, as well as how you can prevent the associated health risks.

Smoking is one of the worst yet preventable dangers to your health. According to the American Heart Association (AHA), cigarettes have more than 5,000 chemicals. Many of these are toxic. Examples include arsenic, formaldehyde, and tar — many chemicals that you would see in manufacturing and processing facilities. Over time, smoking increases your risk of cancer, heart disease, and premature death.

But avoiding exposure to thirdhand smoke as a nonsmoker can be a bit more challenging, especially if you have a family member who smokes. The fact is that thirdhand smoke left over from someone else who smokes affects everyone in your family of all ages.

Effects in children

There are multiple health effects of thirdhand smoke in children. In fact, according to the Mayo Clinic, children are the most vulnerable to such effects. This is because they’re more likely to touch surfaces and put objects near their noses and mouths.

Children exposed to thirdhand smoke at home are more likely to have:

Additionally, children who grow up with parents who smoke are at an increased risk of smoking themselves.


Infants can also be affected by thirdhand smoke. One study suggests that smoke exposure is one of the biggest risk factors for sudden infant death syndrome (SIDS). The other large risk factor for SIDS is improper sleeping position.

Aside from the risk of SIDS, thirdhand smoke exposure sets infants up for some of the same health risks as older children, including frequent illnesses and respiratory problems.

Effects in adults

While not as vulnerable as babies and growing children, adults aren’t immune from the effects of thirdhand smoke, either. You may be at a higher risk of cancer later in life from repeated exposure to cigarette toxins.

While lung cancer is the greatest risk, the AHA also notes that smoke exposure can lead to cancers of the:

  • bladder
  • cervix
  • kidneys
  • mouth
  • pancreas
  • throat

In the short-term, thirdhand smoke can lead to more illnesses and infections. You may also cough more than normal.

Effects in pregnant women

If you’re pregnant, thirdhand smoke exposure can also affect your unborn baby. Whether you breathe in or touch surfaces with chemical residue, you’re at risk of taking in toxins from the smoke into your bloodstream. This can then transfer over to the fetus.

A small study examined the effects of thirdhand smoke exposure on fetal rat lung tissue. It found that certain toxins in cigarette smoke adversely affected lung development.

A baby’s exposure to thirdhand smoke can also lead to respiratory illnesses after birth. According to the American Academy of Pediatrics, smoking during pregnancy also increases the risk of SIDS.

The most effective way to prevent thirdhand smoke is to avoid exposure altogether. If you’re a nonsmoker, this could entail avoiding the homes and common areas of those who smoke. If you smoke, thirdhand smoke is one among numerous reasons you should quit.

Unfortunately, thirdhand smoke can’t simply be “let out” of your car or home. Leaving windows open or your fans on won’t lift the chemical residue off of surfaces. You also can’t smoke in one part of an area and expect the residue to be confined as such. The residue can spread from your clothing and other surfaces throughout other parts of the house.

If you or your home has been exposed to cigarette smoke, there are steps you can take to get rid of the residue that leads to thirdhand exposure. You can:

  • Wash all your clothing.
  • Wash all bedding and linens.
  • Thoroughly mop all hard surfaces.
  • Scrub down counters, walls, and ceilings.
  • Get your carpet and rugs professionally cleaned.
  • Clean all toys.
  • Wash all other fabrics around your home, including furniture.

As a rule of thumb, if a building smells like smoke, there’s probably residue left on surfaces and needs a thorough cleaning.

Another way to prevent thirdhand residue from spreading to others is to make sure smokers change their clothing and wash their hands often. This is especially important before contact with children and infants.

Thirdhand smoke is relatively new in the world of cigarette smoke research, but the phenomenon itself is anything but. It’s also important to note that thirdhand smoke accumulates over time.

Until researchers know more about thirdhand smoke and its wide range of health risks, the best thing you can do is avoid exposure altogether. This means you must avoid all forms of cigarette smoke, including firsthand and secondhand.

If you’re a smoker and need help quitting for the sake of you and your loved ones’ health, see your doctor for advice.