Third-hand Smoke and Your Health

  • Published
  • By Guy Leahy
  • Health Promotion Flight

Most of us are familiar with secondhand smoke (tobacco smoke from a burning cigarette, cigar or pipe). Third-hand smoke (THS), by contrast, is not as well known. Third-hand smoke is the toxic residue that remains on clothes, furniture or in dust after tobacco use. Third-hand smoke is also the smelly odor in a room, or on a smokers clothing. Smokers carry THS around with them wherever they go, and any object they touch will be contaminated with it. Third-hand smoke can be inhaled or ingested as dust and can be absorbed into the skin by direct contact. 

Third-hand smoke is known to last for a long time; one study found that THS was still present in homes of recently quit smokers for at least six months after they had stopped smoking.

The same study found detectible levels of THS toxins in the urine of recently quit smokers, as well as non-smokers that lived with them. Most hotels have smoking and non-smoking rooms. The idea behind this is that non-smokers will be protected from smoking residue. Recent research suggests this is not the case. One study found that even walking by the closed door of a hotel room where smoking was permitted resulted in contamination by THS. Another study found that in hotels with smoking and non-smoking rooms, even the non-smoking rooms were contaminated with THS.  Only hotels that were 100% smoke free were safe from THS. 

Third-hand smoke is also commonly detected in automobiles. One study found high levels of THS on the dashboards, dust and in the air inside the car. Third-hand smoke is also prevalent in rental cars. More concerning is that traditional cleaning methods (wiping, vacuuming) did not significantly reduce THS contamination.  

Young children living in homes of smokers may be at a greater risk from THS, as they are in close contact with sources of THS as they crawl.

Studies on the health effects of THS are relatively new. However, these studies have produced a growing list of health concerns associated with THS.

Third-hand smoke impairs the ability of wounds to heal, and could increase the risk of surgical wounds to reopen in patients contaminated with THS. Exposure to it causes damage to lung tissues, which may ultimately result in scarring and the increased risk of lung fibrosis, which can be fatal.  

In animal models, THS increases the risk of lung cancer. Third-hand smoke has negative effects on the liver; it increases the risk of nonalcoholic fatty liver disease (excess fat stored in and around the liver). This disease can lead to scarring or cirrhosis of the liver, as well as liver failure and liver cancer. In addition, exposure to THS significantly elevates triglycerides (blood fat levels), low-density lipoprotein cholesterol (the “bad” cholesterol) and lowers high-density lipoprotein (the “good” cholesterol).

Third-hand smoke elevates fasting blood sugar levels, and increases the risk of developing pre-diabetes and type two diabetes. Third-hand smoke also decreases the efficiency of the hormone insulin to lower blood sugar levels, which leads to the development of insulin resistance. Third-hand smoke exposure in human cell cultures results in genetic damage to DNA, which could lead to the risk of developing cancer.

In animal models, exposure to THS causes DNA damage to reproductive cells; this genetic damage was replicated in sperm cells. The resulting offspring exhibited cognitive deficits, and displayed behavioral traits such as hyperactivity and attention deficit.

If you would like more information about THS, contact the Health Promotion Flight at 505-846-1186. You can also learn more by joining our Facebook group, KAFB Health Promotion.