Why you should never smoke inside
Carcinogenic third-hand smoke lingers in your carpet, walls, and loved-ones for at least six months
Cigarette smoke lingers in your home for more than six months, a new study warns.
Even when you quit smoking, carcinogens from tobacco remain embedded in sofas, wall, and carpets long after.
And people within the home - whether smokers, ex-smokers, or non-smokers - will also have elevated levels of the dangerous chemicals.
Researchers at San Diego State University insist the findings should serve as a warning to smokers that their habit inflicts lasting damage on their loved-ones too.
'It's important to know how long thirdhand smoke lingers in a home environment and if the former smoker and other residents are exposed to its toxic compounds,' said Georg Matt, the study's lead author and a psychology professor at SDSU.
Professor Matt and his colleagues recruited 90 smokers who were about to quit smoking for the study, published in the journal Tobacco Control.
Over the course of six months, the researchers periodically visited their homes.
They took swabs of the walls and doors, dust samples from the floor, and urine and hand-wipe samples from the residents.
Analyzing those samples, they looked for the presence of any tobacco-related chemicals such as nicotine, cotinine and the potent lung carcinogen known as NNK.
Only eight per cent of the 90 homeowners managed to successfully quit.
Of those eight per cent, the home surfaces and residents' fingers showed an immediate, significant drop-off in nicotine. However, that downward trajectory was short-lived, and remained at higher-than-normal levels for the rest of the study.
The most concerning finding was in the dust samples from the floor: the levels of nicotine and NNK remained virtually unchanged for the entire six months.
And tests on people living in the homes showed little to no reduction in their levels of carcinogenic compounds for the duration of the study.
'The question we were trying to answer is, 'How quickly does your home become truly smoke-free?'' Matt said.
'You may have quit smoking and become a nonsmoker, but your home still carries the legacy of tobacco smoke.
'Thirdhand smoke consists of gases and ultra-fine particles that go deep into the carpet, upholstery and fabrics, and they even penetrate deep into walls and furniture.
'Tobacco smoke does not simply disappear. Smoking indoors builds up a reservoir of chemicals that leaves a long and toxic legacy of tobacco use.'
This is not the first mention of thirdhand smoke.
For years, scientists have been finding evidence that carcinogens in the environment affect others even after smoke has cleared.
But little was known about what happens to the thirdhand smoke that has built up in the homes of smokers after they quit.
SDSU's team of tobacco researchers, chemists, and environmental scientists are among the leaders in the field exploring the properties and dangers of thirdhand smoke.
Previously published work has shown that unsuspecting nonsmokers are likely to be exposed to thirdhand smoke when they move into a new apartment, stay at a hotel, visit a casino and rent a car.
Professor Matt speculates that the lingering smoke may be one of the reasons that makes it so hard to quit smoking. The smell is incredibly difficult to get rid of, meaning there is a constant tease to pick up the habit again.
That is something he hopes to explore in future studies.
But regardless of the stumbling blocks, Professor Matt urges smokers to do everything they can to quit.
'Smoking cessation [quitting] is the single most important activity you can do to improve your health,' Matt said.
'As smokers work towards sustained cessation, it is important to stop smoking indoors immediately.
'Their nonsmoking friends will thank them, and they will prevent thirdhand smoke buildup in their home.
'This will eventually help everybody to live in a completely tobacco free home when they are ready to quit forever.'
(C) Daily Mail, London