Leftover cigarette smoke that clings to walls and furniture could pose a serious threat
This picture is used for representation purpose only. Photo:AP
Washington: A compound from third-handsmoke, which forms when second-hand smoke reacts with indoor air, damages DNA and sticks to it in a way that could potentially cause cancer, scientists have warned.
Leftover cigarette smoke that clings to walls and furniture could pose a serious threat, especially to young children who put toys and other smoke-affected items into their mouths, researchers said.Bo Hang, a scientist at Lawrence Berkeley National Laboratory (LBNL) in the US, said that although the idea of third-hand smoke made its debut in research circles just a few years ago in 2009, evidence already strongly suggests it could threaten human health.
"The best argument for instituting a ban on smoking indoors is actually third-hand smoke," said Hang. Researchers have found that many of the more than 4,000 compounds in second-hand smoke, which wafts through the air as a cigarette is smoked, can linger indoors long after a cigarette is stubbed out.
Based on studies led by Hugo Destaillats, also at LBNL, these substances can go on to react with indoor pollutants such as ozone and nitrous acid, creating brand-new compounds, some of which may be carcinogenic. One of those compounds goes by the acronym NNA. Hang's research has shown that NNA, a tobacco-specific nitrosamine, locks onto DNA to form a bulky adduct (a piece of DNA bound to a cancer-causing chemical), as well as other adducts, in lab
test tubes.
Other large compounds that attach to DNA tend to cause genetic mutations. NNA also breaks the DNA about as often as a related compound called NNK, which is a well-studied byproduct of nicotine and a known potent carcinogen. This kind of DNA damage can lead to uncontrolled cell growth and the formation of cancerous tumours. Just as it took years to establish the cancer-causing effects of first-hand smoke that is inhaled as a person breathes in directly from the cigarette, making the connection between third-hand smoke or NNA and cancer could take a long time, Hang said.
The biggest potential health risk is for babies and toddlers, Hang noted. As they crawl and put their hands or toys in their mouths, they could touch, swallow or inhale compounds from third-hand smoke. So far, the best way to get rid of third-hand smoke is by removing affected items, such as sofas and carpeting, as well as sealing and repainting walls, and sometimes even replacing contaminated wallboard, Hang said.
( Source : PTI )
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