Third-hand smoke damages human DNA

Thelma Dumpit-Murillo

Thelma Dumpit-Murillo

We’ve all heard about the dangers of passive smoking or second-hand smoke. But ever heard of third-hand smoke?

From Health Justice Philippines comes this:

Smoking has been identified as the world’s biggest killer, killing nearly 6 million people every year, according to the World Health Organization (WHO). That’s more people than tuberculosis, HIV and AIDS combined. Exposure to second-hand smoke kills over 600,000 non-smokers every year. Now, a new study shows that exposure to third-hand smoke from cigarettes causes significant genetic damage to human cells – and that it becomes more harmful, the danger increasing, over time.

Third-hand smoke is the residue created once second-hand smoke from cigarettes has disappeared. It clings to virtually all surfaces, such as walls, furniture, and most especially on fabrics. Third-hand smoke can cling to materials long after they have been washed.

The study, led by researchers from the Laurence Berkeley National Laboratory at the University of California, was conducted by placing paper strips in smoking chambers, simulating short (acute)- and long (chronic)- term exposures. The acute (short-term exposure) samples, generated at Berkeley Lab, were exposed to five cigarettes smoked in about 20 minutes, and the chronic (long-term exposure) samples were exposed to cigarette smoke for 258 hours over 196 days. During that time, the chamber was also ventilated for about 35 hours.

The samples were subjected to genotoxicity testing, a process used to determine whether a substance, product or environmental sample induces genetic damage. Through such test, researchers can identify potential hazards for human health and environmental organisms due to DNA damage and mutation induction. Genotoxicity is associated with the development of diseases and is a critical mechanism responsible for many types of cancer caused by smoking and second-hand smoke exposure.

In testing for genotoxicity, the researchers found that third-hand smoke can cause both DNA strand breaks and oxidative DNA damage, which can lead to gene mutation.

“Tobacco-specific nitrosamines, some of the chemical compounds in third-hand smoke, are among the most potent carcinogens there are,” said Lara Gundel, Berkley Lab scientist and co-author of the study. “This is the very first study to find that third-hand smoke is mutagenic,”

So how many of our smoking legislators will be willing to listen, you think? Your guess is as good as mine.

The study also suggests that chronic third-hand smoke exposure is worse than acute exposure. More DNA damage and higher concentrations of chemical compounds existed in samples exposed to third-hand smoke compared to samples exposed to second-hand smoke. This suggests that the noxious and oftentimes invisible residue known as third-hand smoke becomes more dangerous over time.

The results of the new study distressed local health advocates, who have been pushing for the implementation of more effective tobacco regulation policies, including those mandating more smoke-free environments in order to protect the public.

“These new findings clearly show that laws mandating 100% smoke-free environments are the only effective way to protect the public,” said Atty. Diana Trivino, Project Manager at public health NGO HealthJustice.

“We hope our newly-elected lawmakers will demonstrate their commitment to the people by pushing for more comprehensive smoke-free laws and guaranteeing 100 percent smoke-free environments. We hope they realize that the lack of protection from smoking and from exposure to second-hand and third-hand smoke goes against their duty to uphold the Filipino’s right to health.

“The people need to be protected from tobacco companies, most especially the smokers themselves,” said Emer Rojas, President of the New Vois Association of the Philippines.

“Implementing smoking bans and creating smoke-free environments do not just protect non-smokers. Studies now show that they help motivate smokers to quit the deadly addiction as well.”
God is Great!


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