Thirdhand smoke is widespread and may be dangerous, mounting evidence shows

First came doctors’ warnings about cigarettes. Then came discoveries about the danger of secondhand smoke. Now, a growing number of scientists are raising the alarm about thirdhand smoke — residual chemicals left on indoor surfaces by tobacco smoke.

Mounting research has shown such potentially hazardous residue can be absorbed through the skin, ingested and inhaled months and even years after the smoke has dissipated.

One study published this year showed thirdhand smoke increased risk of lung cancer in mice. Another study published last year showed an increased risk of liver damage and diabetes in mice. A third study published this year focused on casinos and showed that six months after smoking was banned, heavy smoke residue remained on the walls and carpet.

The latest study, published Wednesday in the journal Science Advances, shows how tobacco smoke from outdoor air can seep into a nonsmoking classroom and coat its surfaces, and how those hazardous chemicals often become airborne again and circulate throughout buildings via central air-conditioning systems.

Read more at the Washington Post