The term "third-hand smoke" has recently entered the medical lexicon. While "second-hand smoke" is a common term in the English vernacular, most people would be hard pressed to define "third-hand smoke." Third-hand smoke is a term coined by Jonathan Winickoff and his research team at the Dana-Farber/Harvard Cancer Center.

Third-hand smoke is what is left behind after a cigarette has been put out. Third-hand smoke is the smell that assaults your senses when you walk into a room where someone had been smoking today, yesterday or even last week. Third-hand smoke is the toxic residue from cigarettes that coats the surface of objects. Third-hand smoke is the inescapable cloud that envelopes even non-smokers, clinging to their hair and clothing, after a night out in a smoke-filled club.

Exposure to third-hand smoke should be avoided by all. The residue from cigarettes contains 250 toxins including lead, cyanide and arsenic, all chemical substances that no one should deliberately ingest. However, children are placed at particular risk by exposure to third-hand smoke for several reasons. First, children, particularly infants and toddlers, are in constant contact with the environment, not only touching things but also sucking on or putting these things in their mouths. Thus, children are in danger of ingesting toxins from cigarettes that were smoked days or weeks ago. Second, children are still developing and are much smaller than adults. Thus, these toxins can have an adverse impact on the growth and development of children at a particularly vulnerable time. Even minuscule levels of exposure have been linked to diminished IQs.

The take-home message is that everyone, but especially children, need to be protected from cigarette smoke. Parents should be made aware that the only way to protect children is to not allow smoking in their homes at all. This prohibition should include the space around the home as well to ensure not only clean air, but also clean surfaces.