Research on the effects of third-hand smoke — tobacco that builds up on surfaces over time — is still fairly new, but a recent study found that nicotine residues can become airborne again. Paul Lyons, a professor of family and community medicine at Temple's School of Medicine, said smoking outside isn't enough. "I think there should be a lot more education around this issue of smoking outside the house or smoking outside workplaces with the expectation that when you come back in you're not bringing any of that with you."