Months after the smoke has cleared, toxic residues still coat surfaces in indoor areas where it was once allowed, new research reveals.
Researchers from San Diego State university found that decades of heavy smoking in casinos caused massive build-ups of toxic residue on walls, furniture, and in carpets.
The residue – known as ‘thirdhand smoke’ – declined after smoking was banned in a Northern California casino.
But even six months later, toxic tobacco smoke residue remained above levels found in formerly smoke-friendly hotels or private homes where bans had been introduced, suggesting that the damage in casinos is far harder to undo.
Casino surfaces remain coated by toxic residues even months after smoking is banned, a new study reveals
Most public spaces in the US now have laws against smoking indoors in order to protect public health.
But several states – including Nevada – allow ‘adult venues’ like casinos to allow smoking indoors.
In some states, including California, where the new study was conducted, tribal casino are exempt from otherwise universal bans.
Thirdhand smoke has been linked to increased risks for cancer, including in a growing number of cases where lung cancer has seemed otherwise inexplicable by first or secondhand smoke exposure.
These residues stay embedded in fibers or dust after there are any detectable signs of smoking, like visible smoke or even its linger scent.
Experts worry that even if the hints of toxins are not themselves enough to do any real harm, they may mix with other chemicals in the air to become carcinogenic.
The researchers said the findings are particularly important information for considering the health and well-being of casino staff and frequent guests.
Lead study author and psychologist Dr Georg Matt said it is also important for casino operators considering the expense and effort needed to clean up the toxic legacy of tobacco use.
Dr Matt said: ‘Casinos are unusual environments because of the amount of smoking that takes place 24/7 over long periods of time.
‘Over years of smoking, layers of smoke residue stick to surfaces and penetrate deep into materials.
‘If you work at a casino that allows smoking or are a guest, you already know you inhale secondhand smoke every time you breathe.
‘Because the tobacco smoke residue remains long after a smoking ban, you will continue to get exposed even after the secondhand smoke has disappeared.’
For the study, Matt and colleagues looked to a casino outside Redding, California, that opened in 1993. In 2014, the casino banned smoking inside the casino for 11 months before rescinding that ban and returned to being a smoking-permissible building.
The researchers took surface samples from eight areas inside the casino twice before the smoking ban took effect, then again six times during the duration of the ban.
They also examined fingers and urine of non-smoking participants who visited the casino over that time.
The researchers looked for chemical signatures associated with byproducts of tobacco combustion and exposure.
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.
Dr Matt and his colleagues have previously found that these thirdhand smoke residues linger in homes for months after indoor smoking has ceased, but they weren’t sure what they would find in an environment like a casino.
He said that while casinos often have higher concentrations of smokers as guests than homes do, and smoking can take place virtually at all times of the day, casinos are much larger than homes and often feature industrial-strength ventilation systems.
According to the data he and his team gathered, casinos’ ventilation systems and larger sizes didn’t seem to matter much when it came to the collection of toxic residues.
A smoking ban and good ventilation cleared the air, but did little to reduce the levels of thirdhand smoke in cloth, on surfaces and accumulated in dust particles throughout the casino’s interior.
Even six months later, nonsmokers who frequented the casino encountered more thirdhand smoke than nonsmokers who live in homes previously inhabited by smokers, according to the findings published in the journal Tobacco Control.
Dr Matt said: ‘The casino was much more polluted with thirdhand smoke than any nonsmoker home we have examined to date.
‘That is, nonsmokers are at risk of being exposed to higher concentration of thirdhand smoke in a casino than they would in a thirdhand smoke-polluted home.’
He said only by intensive surface cleaning – and in some cases even surface replacing – can casinos hope to make their environment significantly safer for guests after imposing a smoking ban.
Dr Matt said that the longer tobacco is smoked indoors, the more difficult and costly it will become to clean up that indoor environment.
He added: ‘Tobacco should never be smoked indoors unless you are prepared to pay the price for extensive clean up.
‘The sooner you stop smoking indoors, the sooner you will benefit from clean air and the less it will cost to clean up the toxic legacy.’