Most parents are well aware that smoking in the presence of their children can harm the health of their little ones. Now, another invisible threat has been identified — thirdhand smoke.

The term was coined to describe cigarettes’ lingering aftereffects, which are just as harmful to children as secondhand smoke. A few days or even weeks after a cigarette is smoked, particulates remain on countertops, floors and other surfaces. Curious children crawling on the floor, pressing their faces against walls and tables, and putting objects into their mouths are at increased risk of coming into contact with these thirdhand toxins.

Jonathan Klein, M.D., FAAP, an associate executive director of the American Academy of Pediatrics, likens second- and thirdhand smoke to lead. “These days,” he said, “people wouldn’t think twice about the fact that you can’t have lead paint flakes in a house where children live. So if you think about the parallel, then is it OK to have circulating second- and thirdhand smoke toxins in the air that children are forced to breathe? No, of course not.’

Here are some ways to limit or prevent your children’s exposure to the toxins:

  • Hire only nonsmoking baby sitters and care providers.

  • If smokers visit your home, store their belongings out of your children’s reach.

  • Never smoke in your children’s presence or in areas where they spend a lot of time, including your home and car.

  • If you smoke, quit. Talk to your child’s pediatrician or to your own doctor to learn about resources and support networks. Among them are the American Lung Association,; the U.S. Environmental Protection Agency’s Smoke-Free Homes program,; and Clinical Effort Against Secondhand Smoke Exposure,