When home owners find their rental property has been poisoned by tenants running a meth lab, they’re obliged to pay up to $120,000 to get the house stripped and cleaned.
After all, home owners are required to provide a safe environment for their tenants – although dangerous mould and damp conditions seem to go through to the keeper.
But what about cigarette smoke? It doesn’t take long for a pack a day to sink into the carpets, couch, curtains and clothes.
The residue left behind is known as third-hand smoke (THS), and includes nicotine and cancer-causing chemicals such as formaldehyde, and naphthalene.
According to the Mayo Clinic, airing out rooms, opening windows, using fans or air conditioners, or confining smoking to only certain areas in the home of a home won’t eliminate or prevent this nasty residue from taking root.
And just like meth, third-hand smoke can’t be removed with regular household cleaning.
Two new studies suggest we might want to think twice before borrowing a jumper or underpants belonging to a smoker.
Under your skin
Scientists at the Berkeley Lab in California first identified third-hand smoke as a potential health hazard a decade ago.
They discovered that aerosolised nicotine, released during smoking and vaping, “adsorbs to indoor surfaces, where it can interact with a compound present in indoor air called nitrous acid (HONO) to form strongly carcinogenic compounds called tobacco-specific nitrosamines (TSNAs)”.
In a new study they found that concentrations of these toxic chemicals can linger in indoor environments to an extent that exceeds local risk guidelines, “meaning that non-smokers can be exposed to health risks by living in contaminated spaces”.
This suggests that if environmental authorities were to audit the homes of smokers, they could potentially be evicted, and the house subjected to an intensive cleaning order.
Further, the researchers found that those “strongly carcinogenic” TSNAs can seep through the skin, a process known as ‘dermal exposure’.
Dermal exposure can occur by sleeping on smoky bed sheets, or handling the clothing of a smoker.
A unique and nasty ingredient
“Nicotine is released in large amounts during smoking, and it coats all indoor surfaces, including human skin,” said Dr Xiaochen Tang, who led the Berkeley experiments.
“We found that the presence of skin oils and sweat on model surfaces led to a higher yield of TSNAs in the presence of HONO, compared with clean surfaces.”
The Berkley team also experimented with a compound called NNA which is known to be a unique compound of third-hand smoke residue.
Because traces of NNA can be found in urine and blood samples from people exposed to thirdhand smoke, NNA serves as a useful specific measure third-hand smoke exposure.
After the scientists exposed human lung cells to NNA at various doses, they found that NNA was toxic and disruptive to human DNA, leading to an elevated risk of cancer.
The fact is, more toxins enter the body via your skin than from breathing.
Dermal contact impairs wound healing
In June, researchers from the University of California, Riverside published a study which found that dermal exposure to nicotine concentrations found in thirdhand smoke – or from electronic cigarette spills – damage the skin.
“We found dermal contact with nicotine may impair wound healing, increase susceptibility to skin infections due to a decrease in immune response, and cause oxidative stress in skin cells,” said Dr Giovanna Pozuelos, who recently completed her PhD in cell, molecular, and developmental biology.
According to Dr Pozuelos, the most susceptible individuals include those with skin conditions such as diabetic-related ulcers or arterial ulcers. But toddlers and infants are at particular risk.
“Toddlers and infants, who tend to crawl on contaminated surfaces or have frequent contact with indoor surfaces, are particularly susceptible to high dermal exposure,” she said.
