By now, most people are familiar with the concept of secondhand smoke (the smoke that’s either exhaled by a smoker or emitted from the end of a cigarette, pipe, or cigar). Yet, far fewer have heard of “thirdhand smoke” \u2014 the residue of nicotine and other chemicals that lingers on indoor surfaces such as furniture, walls, drapes, and bedding.\nThe chemicals can react with other indoor pollutants including ozone and nitrous acid, forming dangerous new compounds. Smokers themselves can even release these toxins from their skin, hair, and clothing. If you’ve ever wondered why a home still smells like smoke long after smokers have moved out, or why your friend gives off a smoky odor even when he isn’t smoking? That’s thirdhand smoke.\nSecondhand Smoke Exposure\nAlso known as environmental tobacco smoke, exposure to secondhand smoke has been linked to an increased risk of lung cancer and other health problems. While the effects of third hand smoke haven’t been as well established, some experts believe that it may also be hazardous.\nResearchers know that some of the new compounds formed by thirdhand smoke may damage DNA and suspect that they may also have the potential to cause cancer. They may also trigger asthma and allergy attacks.\nPreventing Secondhand Smoke Exposure\nSome studies have shown that thirdhand smoke can linger for decades in dust, walls, flooring, and other parts of homes \u2014 even if no one has smoked in the area for years. Worse, it’s nearly impossible to eliminate unless you remove all of the drywall and flooring in a home.\nWho Has a Higher Risk for Thirdhand Smoke Exposure?\nCertain people may be at higher risk for exposure to thirdhand smoke than others, including:\n\nChildren, who typically crawl on floors and carpets and may teethe on furniture.\nChildren whose parents smoke. Even if a parent smokes away from home or outside, the chemicals that remain on their skin and clothing can expose kids to third hand smoke.\nPeople who work in or clean casinos, hotels, bars, clubs, or other locations where people smoke or used to smoke\nPeople who regularly drive rental cars or used cars that were previously owned by smokers\n\nUnfortunately, using fans, airing out rooms, and using cleaning products do little to remove this toxic residue.\nNext to completely gutting a house, the only surefire way to avoid third hand smoke is to make sure you create a smoke-free environment in your home and car. That’s one more excellent reason not to smoke \u2014 and to quit if you do.