Study says chemical, tobacco merge to form carcinogens

WALNUT CREEK, Calif. (MCT) — A common indoor air chemical reacts with residues of tobacco smoke clinging to clothing, skin and surfaces to form potent carcinogens, researchers at Lawrence Berkeley Laboratory reported in a study published Monday.

A few years ago, researchers began paying closer attention to the potential health effects of "thirdhand smoke," which is a thin layer of toxic substances from tobacco smoke that settles on surfaces long after cigarettes have been extinguished.

The Berkeley scientists, however, are the first to find that nitrous acid, an indoor air pollutant created by gas appliances, vehicle engines and tobacco smoke, reacts with nicotine found on surfaces.

"We want to make people aware that there's a potential hazard from thirdhand smoke that has not been recognized before," said Lara Gundel, one of the authors of the study, which was published in the Proceedings of the National Academy of Sciences.

The term "thirdhand smoke" was coined in 2009 in a study in the journal Pediatrics, which found that 65 percent of nonsmokers thought that the residue of tobacco smoke found on furniture and drapes, in rugs and dust, and on skin and clothing, can harm children and infants.