Beyond passive smoking - what is thirdhand smoke?

Smoking has been found not only to harm you and those breathing the same air while you smoke, but also to contaminate clothing, hair and surfaces in the home and car, causing other long-term problems.

Smoke from the tip of a cigarette contaminates many surfaces and is even absorbed through the skin. When tobacco burns, more than 50 carcinogenic substances are released among more than 2000 harmful substances. Now it has been found that, through surfaces contaminated with these substances in cigarette smoke, their harmful effects are greater and can last longer than previously thought. This condition, called thirdhand-smoke (thirdhand tobacco smoke exposure), has caused type 2 diabetes, hyperactivity and lung damage in mice.

Because the liver and brain play important roles in detoxification, they are thought to be the tissues primarily harmed by thirdhand smoke. Considering the major role the brain plays in behavior, this can be described as quite dangerous.

On September 15, Clinical Science published a study aimed at finding the minimum period of exposure to cigarette smoke required for physical harm. One month of exposure caused liver damage, while two months caused greater molecular damage. Long-term thirdhand smoke exposure was also found to cause insulin resistance (a condition preceding diabetes) in mice.

Liver damage impairs the body’s ability to cleanse itself, and toxins in cigarette smoke cause further damage to the liver. Examination of the brains of mice exposed to thirdhand smoke showed increased stress hormones such as epinephrine. The rise in stress hormones was found to increase further with prolonged exposure, eventually weakening the immune system in the mice.

Thirdhand smoke was also observed to resist even strong cleaning products. Moreover, it is difficult to notice that exposure is occurring. These substances adhere to household items such as curtains, sofas, carpets and upholstery. Although this is harmful to everyone, children in particular frequently encounter toxic substances when they touch their surroundings and then put their hands in their mouths. Even if places where people smoke are ventilated and cleaned, they remain unhealthy environments, especially for children.

At the end of the study, mice exposed to thirdhand smoke were found to be less social, to have insulin resistance problems, and even to have become dependent on thirdhand smoke and experienced behavioral changes. Although this study was conducted in mice, researchers think similar effects will also be seen in humans.

Related Topic:

- How can I quit smoking?