A few years ago we learned cigarettes create not just first and second hand smoke but thirdhand smoke. This is a family of toxic chemicals left by a cigarette long after it's been snuffed out. Now we have more reasons to avoid it.

Research shows chemicals from thirdhand smoke, or THS, bind to our DNA causing damage and mutations that could lead to cancer over time. Cigarette smoke has over four thousand pollutants and they linger on carpets, furniture, walls' even the dust in the air. As some THS pollutants accumulate over time, they become more toxic. They also transform into new compounds when mixed with indoor pollutants like ozone and nitrous oxide to form carcinogens.

Among these is NNA which is similar to a known potent carcinogen called NNK. In the new study, NNA bound to human DNA. Cells exposed to these carcinogens increased DNA damage within twenty four hours and can cause uncontrolled cell growth leading to cancer.

We take in these compounds when we breathe or touch items in areas exposed to thirdhand smoke. But kids ingest these compounds when they put a toy in their mouths, crawl on the floor, or bury their face in a parent who smokes and has it in their hair and clothes. It's even worse for babies with developing lungs. Depending on the type of compound, they can last for hours, weeks, or longer.

When smokers quit they need to take great measures to clean their home. Carpets should be changed, the walls painted or even replaced. But the benefits are enormous.

Forty-four million American adults smoke. It kills more people than HIV, illegal drugs, alcohol, car crashes, and firearms combined. Now there's one more reason to quit.