Experts have now come to the conclusion that third hand smoke increases the risk of lung cancer and have cautioned that tobacco should never be smoked indoors to ensure cleaner air.
A new study released by researchers from San Diego University in Carlifonia, United States (US), found that high levels of third hand smoke can linger in gambling casinos, on walls, furniture, and in carpets months after smoking is eliminated.
That, according to them raised the risk of lung cancer. The chemical residues, such as nicotine, cotinine, and the potent lung carcinogen known as NNK, can harm people’s health when they’re exposed to them, even if they aren’t smokers themselves. In 2017, the researchers reported that brief exposure to third hand smoke was associated with low body weight and immune changes in juvenile mice.
In the follow-up study, which was published in ‘Clinical Science, the researchers found that exposure early in life to third hand smoke was associated with an increased risk and severity of lung cancer in mice.
Third-hand Smoke is the poisonous chemical residual of tobacco smoke contamination that clings to clothing, wall, furniture, carpet, cushions, hair, skin and other materials after the cigarette is extinguished. Usually, the nicotine residues soak into a smoker’s skin and clothing even if they smoke outside.
Studies have confirmed that third hand smoke in indoor environments is widespread, and usual cleaning methods don’t remove it.
Since exposure to third hand smoke can occur through inhalation, ingestion, or through the skin, young children who crawl and put objects in their mouths are more likely to come in contact with contaminated surfaces and are the most vulnerable to its harmful effects.
Previous study at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) identified third hand smoke as a health hazard 10 years ago.
In the new study, a strain of mice that is susceptible to lung cancer was housed with fabric infused with third hand smoke from the age of four to seven weeks.
The mice ingested a dose comparable to the ingestion exposure of a human toddler living in a home with smokers.
Forty weeks after the last exposure, the mice were found to have an increased incidence of lung cancer (adenocarcinoma), larger tumors, and a greater number of tumors, compared to control mice.