Third-hand smoke poses health risks

Smoking is one of the biggest causes of preventable disease and death, and doctors are increasingly concerned about the impact of second-hand smoke on the health of children in particular.

Now a new study has identified "third-hand" smoke as a another potential hazard of tobacco. Third-hand smoke is a description for the residues of smoking left behind in carpets, furniture, clothing and other surfaces.

A previous study had found that when these residues come into contact with a common air pollutant, nitrous acid, it can result in the production of tobacco specific nitrosamines (TSNAs) - cancer causing chemicals (for more details see this article : "Third-hand smoke warning").

The new study has found even more worrying results - that third-hand smoke can combine with ozone (a form of oxygen) in the air to form toxic compounds.

The scientists selected a variety of different materials commonly found in typical indoor surfaces, including cellulose (a component of wood furniture), cotton, and paper, and exposed them to a combination of nicotine and indoor air.

They found that nicotine interacts with ozone, in indoor air, to form potentially toxic pollutants on these surfaces. The researchers noted that: "Given the toxicity of some of the identified products and that small particles may contribute to adverse health effects, the present study indicates that exposure to [third-hand smoke] may pose additional health risks".

The study is published in the journal Environmental Science & Technology.

This article was published on Thu 13 January 2011