Those of us who experienced life before a smoking ban remember it well. A night out on the town left you with more than an empty wallet and high spirits; it also left you with a stench so potent it permeated hair and clothing and often necessitated jumping in the shower before hitting the hay. Even if you never lit up, smoke-filled bars and restaurants were enough to leave a lasting impression on your clothes, something you could smell days after your jeans had been dumped into the dirty laundry hamper.
Gut reaction then told me what we all know now—secondhand smoke and its lingering scent are composed of some dangerous stuff. But although the dangers of secondhand smoke are well-documented, it wasn’t until recently that the leftover toxic brew swirling around in the fabric of my jeans was given a name—thirdhand smoke.
Once, Twice, Three Times a Toxin
A study published in the January 2009 issue of Pediatrics coined the term “thirdhand smoke,” which the researchers describe as “residual tobacco smoke contamination that remains after the cigarette is extinguished.” Although many media outlets reported it as a “new” cigarette hazard, the research didn’t actually find a new source of exposure. Instead, the objective of their study was to determine the beliefs of smokers and nonsmokers regarding thirdhand smoke and their children, and correlate this with household smoking bans.
Not surprisingly, the researchers found that the majority of both nonsmokers and smokers agreed that secondhand smoke harms children’s health. However, only 65 percent of nonsmokers and 43 percent of smokers thought that thirdhand smoke harms kids. Perhaps most importantly, beliefs about thirdhand smoke predicted whether there was a strict home smoking ban. If you believe that the residues aren’t a problem, you’re more likely to light up in the house.
But what are the risks of the particulate matter, dust, and chemicals left over after the smoke has cleared? Although this study didn’t address that fundamental question, others have.
Where There’s Smoke, There’s Trouble
A 2004 study published in Tobacco Control found that dust and surfaces in smoker’s homes are contaminated with environmental tobacco smoke (ETS) residue and that children are exposed to these contaminants. By comparing cotinine levels (a nicotine metabolite) in infant urine, the researchers found that infants of smokers are at risk of exposure to ETS through dust, surfaces, and air—even when no smoke is present. Although smoking away from the infant and outside lessens the amount of ETS exposure, it doesn’t completely protect a smoker’s home from contamination.
Other research has found that tobacco toxins persist well beyond the time of active smoking. Though most of us think the smoke is the problem, tobacco toxins can turn into particulate matter that drifts into carpets, upholstery, clothing, hair, and dust. And the smell that is immediately recognizable when entering a smoker’s car or home is due to toxic compounds “off gassing” into the air.
Children, because of their small size and penchant for hanging out on the floor and putting things into their mouths, are particularly susceptible to ingestion and inhalation of these lingering chemicals. (Pets are also susceptible to the ill effects of ETS.) When parents don’t have a strict no-smoking-indoors rule, they may still unwittingly expose their kids to the carcinogens, heavy metals, and toxins present in ETS.
The significance of the Pediatrics study, besides coming up with a catchy phrase, was to show that not knowing about this thirdhand smoke could have serious consequences.
We Can’t Just Wave Away the Chemicals
Although there aren’t studies directly linking thirdhand smoke to disease, the health consequences of exposure to the chemicals found in secondhand smoke are numerous. In 2006, the Surgeon General issued a report stating that there is no safe level of secondhand smoke exposure; it has been linked to heart disease, sudden infant death syndrome, lung cancer, decline in cognitive function, and can exacerbate conditions like asthma, wheezing, and respiratory infections and conditions.
Because the smoke contains numerous toxins and carcinogens, thirdhand smoke is likely to contain some, if not all, of the same stuff. Also, many people feel that wafting away smoke prevents exposure. But according to the Office of the Surgeon General, opening a window, sitting in a separate area, or using ventilation or a fan can’t eliminate secondhand smoke exposure.
Although smokers may feel that their home is their last bastion where they can smoke indoors, parents who smoke may want to think twice about smoking in a confined space with their little ones.