One of the pernicious things about bad habits is the way they adversely affect people who aren’t involved in them. It’s old news that smoking cigarettes does terrible things to both smokers and the people around them. We also know that secondhand smoke, inhaled by hanging around smokers is also dangerous. Well, a new study ups the ante yet again. Led by researchers at the Lawrence Berkeley National lab, the study revealed that long after a cigarette is put out, the tobacco smoke residue that clings to surfaces reacts with the common indoor air pollutant nitrous acid to produce dangerous carcinogens.
I recently wrote about the lingering effects of third-hand smoke. In that article, I focused on the 250 poisonous gases, chemicals, and heavy metals contained in cigarette smoke and how these toxins which deposit on household surfaces pose significant dangers to infants, toddlers, children and adults alike. As I said, the dangerous components of cigarette smoke include a hair-raising array of poisons, including hydrogen cyanide, used to create chemical weapons; carbon monoxide; butane, which is a component of lighter fluid; ammonia; toluene (found in paint thinners); arsenic; lead; cadmium (a component of batteries); and the highly radioactive polonium-210. In fact, cigarette smoke contains eleven carcinogens categorized as Class 1, the most dangerous kind. And these carcinogens settle on every exposed surface when the butt goes out, so when kids crawl, roll, lounge, and play on the carpet or floor on which these compounds reside, there is real danger for them.
The new study adds an alarming wrinkle. Previously, nicotine itself was thought to be relatively nontoxic, even if addictive. Wrong, wrong, wrong, according to Hugo Destaillats, a chemist with the Indoor Environment Department of Berkeley Lab’s Environmental Energy Technologies Division. Says Destaillats, “…residual nicotine reacts with ambient nitrous acid [and] forms carcinogenic tobacco-specific nitrosamines — known as TSNAs. TSNAs are among the most broadly acting and potent carcinogens present in unburned tobacco and tobacco smoke.” In other words, in addition to all its other toxins, cigarette smoke leaves a residue of nicotine on your household surfaces, and nitrous acid, which is everywhere in most households (it comes from un-vented gas appliances, for instance), converts it into very nasty stuff.
And lest you think that we’re talking about paltry amounts of TSNA carcinogens hanging around your house as a result of nicotine residues, think about this. Samples exposed to “high but reasonable” concentrations of nitrous acid were found to contain 10 times higher levels of newly formed TSNAs than what was present in the samples prior to exposure, plus the conversion rate is very fast. In other words, a little nicotine goes a very long way and acts very quickly in creating carcinogens. The study showed an up to .4 percent conversion of nicotine to TSNAs in the first hour alone. Lead study author Mohamad Sleiman said, “Given the rapid sorption and persistence of high levels of nicotine on indoor surfaces, including clothing and human skin, our findings indicate that third-hand smoke represents an unappreciated health hazard through dermal exposure, dust inhalation and ingestion.”
Even on metal surfaces the danger is quite significant. The surfaces of the stainless steel glove compartment in the truck of a heavy smoker revealed substantial levels of the TSNAs known as NNN and NNK. Both are potent carcinogens. A 1980 study published in Cancer Research showed that, “NNN induces lung adenomas in mice, esophageal and nasal cavity tumors in rats, and tracheal tumors in hamsters.” NNK was found to be even more carcinogenic.
And TSNAs don’t only cause lung and esophageal cancer. They’ve also been linked to oral cancer and cervical cancer. In fact, studies have shown you don’t need to smoke nicotine to reap the punishment. NNN and NNK have been strongly linked with the excess of oral cancers found among snuff users. That ought to give you chills when you think about your toddler putting a toy in his mouth that he dragged across a carpet that smells of tobacco smoke.
Even if you go outside to smoke, the nicotine residue that you bring back into the house (or car) on your clothes and skin rubs off on household surfaces and poses a threat. Children and toddlers are most at risk because their young skin is so vulnerable to dermal uptake of TSNAs.
As I’ve said previously, you’re not being overly fussy when you try to avoid being in the presence of tobacco smoke or its residue. Previous research on third-hand smoke supported regulations banning smoking in public buildings and places. Based on this new research, maybe we should require smokers to wash their clothes, shower, and clean the carpet (not to mention the inside of their car or truck) after each cigarette.
I know this might sound a bit mean or vindictive when it comes to smokers. But, really, what’s meaner? Warning smokers about the dangers they present to others one more time, or allowing a toddler to get cancer because they’re crawling on a carpet that stinks of cigarette smoke.