Exposure to tobacco smoke has been linked to lung cancer, heart disease and respiratory illness. In children, exposure exacerbates asthma and increases the risk of respiratory problems and ear infections.
Now, a new study finds that it also increases behavioral problems. Researchers measured a biological marker in the blood called cotinine, produced when nicotine breaks down in the body.
Lead author Kimberly Yolton with Cincinnati Children's Hospital Medical Center says higher cotinine levels correspond to increased behavioral problems at home and at school. "We looked at what's called externalizing behavior problems. Those are the outward behavior problems that most people notice. They are the aggressive behaviors and the hyperactive behaviors and conduct problems that people notice in the school setting," she says.
"We also saw increases in what is called internalizing behaviors, things like a child having increasing levels of anxiety and depression. These are the children that get a stomach ache when they have increasing levels of stress rather than acting out and running crazy through the classroom. They are going to sit in the corner and get a stomach ache instead."
Yolton says children exposed to at least five cigarettes a day were also less able to adapt to changes in routine and make friends. She says what was surprising was that even low levels of cotinine were associated with behavioral problems.
"And to me it just says to parents that we really need to pay attention to where our children are and what kind of exposures they are getting, even when they are not under our care, and try to protect them from tobacco smoke that may in fact affect lots of different areas of their development and behavior."
The research was presented April 30 at the Pediatric Academic Societies annual meeting in San Francisco.