New cancer risk with third-hand smoke

BUFFALO, N.Y. (WIVB) - We've all heard of first and secondhand smoke, but third? The dangers from smoking remain, even after the smoke clears.

When someone lights a cigarette, you can see the smoke. And even if you're a non-smoker, the secondhand smoke can harm you. But when the cigarette is finished, what happens to the chemicals that were in the smoke?

Dr. Mark Travers of Roswell Park Cancer Institute explains, "They don't just disappear. We find that the surfaces around us, whether it's the floor, the ceiling, the walls, the furniture, clothing you're wearing, becomes a reservoir of these contaminants."

Dr. Travers does research on chemical pollutants in smoke. He points out that you know when you're in a room or a car where someone's been smoking.

"Those specific compounds that are found in tobacco smoke are what lead to that characteristic odor. That stale, tobacco smoke smell that we're all aware of," said Dr. Travers.

That's called third-hand smoke. Can it be dangerous? New research shows that nicotine residues on indoor surfaces form new carcinogenic chemicals that aren't in the original cigarette smoke.

Dr. Travers explains. "So there's new compounds, new harmful, cancer-causing compounds, that are formed over time in this third-hand smoke that's on surfaces. And how harmful it is we don't know at this point."

It's easy to eliminate secondhand smoke. Just stop smoking indoors. But what about rooms and cars that are already contaminated? We don't know yet whether those surfaces can be effectively cleaned.

"We don't know what we need to do to say that this is now a safe environment. It was previously contaminated, now it's safe. We don't know; we don't have the evidence. That's part of why it's so scary, because we don't know what we need to do to make it safe," said Dr. Travers.

And we don't know yet how unsafe it really might be. For instance, many people who suffer from secondhand smoke live with someone who smokes, so they're probably also getting a lot of third-hand smoke. It's hard to know how much each type of exposure contributes to their problems.

So what should we do while we're waiting for the answers?

One thing we should do is try to limit a child's exposure. Keep children away from rooms and cars where people smoke, and if you're a smoker, change your clothes before you play with a child.