What is 3rd-hand smoke and is it dangerous?

We all know about breathing second-hand smoke, which can cause cancer, but how about third-hand smoke? Third-hand smoke is the residue left in your clothes, on your furniture, and in your carpeting. Some researchers looking into this issue say it could be dangerous for infants and toddlers.

Antoine Snijders and other researchers at the Lawrence Berkeley National Laboratory at UC Berkeley are studying the effects of third-hand smoke in mice, especially those that are 3-weeks old and younger. They want to find out if third-hand smoke is carcinogenic. They discovered that third-hand smoke affects body weight and the immune system.

In fact, the mice exposed to the material treated with cigarette smoke weighed significantly less than they should have. The researchers say that more studies and eventually human studies should be conducted. Their concern is that infants and toddlers could be most at risk because kids play with toys, crawl on the floor and carpets, and then put their hands in their mouths. That means they have a higher exposure level than other age groups.

It is not clear when additional studies are planned.