Just what is third-hand smoke?

Smoking is bad for your health. And second-hand smoke - the cloud of cigarette exhaust that we inhale when those around us are smoking - is nearly as dangerous.

But what about third-hand smoke? Chances are you've never heard of this concept before, but it "could have some dangerous health consequences," said Greta Roberts Broneil, assistant director of health for the town of Stratford.

Third-hand smoke refers to the chemicals in smoke that stick around long after a cigarette is extinguished. They linger on clothes, in hair, on skin, in carpets and blankets, and on walls, toys and any number of surfaces.

In an effort to inform the public about this little-known concept, Stratford is launching a third-hand-smoke awareness campaign after the start of the new year, according to CTPost.com. The program aims to help people, particularly children, limit their exposure to these chemicals, which can include nicotine, arsenic and lead.

It's not exactly clear how dangerous third-hand smoke is, but health experts said it makes sense that smoke residue can be unhealthy if inhaled or ingested. Broneil said children are particularly vulnerable to third-hand smoke as they're more apt to crawl or roll around on the floor and put toys and other items in their mouths

The American Cancer Society has said that no cancer risks from third-hand smoke have been measured, but the health effects of these residual chemicals are "an active area of research."