Study: Kids May Be Exposed to Second-Hand Smoke by Neighbors

Children who do not live with smokers may still carry chemicals from smoke in their bodies when they live near people who smoke because it can still seep into their homes through walls and shared ventilation systems, according to research published in the journal Pediatrics.

Apartment-dwelling children have more cotinine in their blood, a marker of exposure to tobacco, than children who are raised in detached homes with non-smokers.

The authors analyzed data from a national survey of 5,002 children between six and 18 years old who lived in non-smoking homes. The children raised in apartments and not detached homes had 45 percent more cotinine, a byproduct of tobacco, in their blood.

This research was designed only to determine whether sharing walls with smokers was enough to expose children to chemicals from cigarette smoke. It did not look at whether the health of those children had been compromised.

A second study in the same issue of Pediatrics found that as smoke-free laws get tougher, kids' asthma symptoms decline. Because of such research, some municipalities are beginning to ban smoking in multi-unit housing.

Lead author Karen Wilson, a pediatrician at the University of Rochester Medical Center, noted that previous research on the effects of cotinine has determined that children suffer physiologic changes and cognitive disruption from increased levels of that chemical.

Researchers from the Harvard School of Public Health examined U.S. health data from 1999 to 2006, and found a 33 percent decline in symptoms, including persistent wheeze and chronic night cough, among kids who weren't exposed to smoke.

That same group also found that tougher laws were also linked with lower cotinine levels in children and adolescents, down about 60 percent between 2003 and 2006 in children living in smoke-free homes.