Secondhand smoke exposure and neurobehavioral disorders among children in the United States

The association between parent-reported postnatal secondhand tobacco smoke exposure in the home and neurobehavioral disorders (attention-deficit/hyperactivity disorder, learning disabilities, and conduct disorders) among children younger than 12 years in the United States was examined using the 2007 National Survey on Children's Health. Excess neurobehavioral disorders attributable to secondhand smoke (SHS) exposure in the home in 2007 were further investigated.

The methods used in this study were multivariable logistic regression models that accounted for potential confounders and complex survey designs to evaluate associations.

A total of 6% of 55 358 children (aged < 12 years), corresponding to a weighted total of 4.8 million children across the United States, were exposed to SHS in the home. The weighted prevalence and 95% confidence intervals of each of the children's neurobehavioral outcomes were 8.2% (7.5-8.8) with learning disabilities, 5.9% (5.5-6.4) with attention-deficit/hyperactivity disorder, and 3.6% (3.1-4.0) with behavioral and conduct disorders. Children exposed to SHS at home had a 50% increased odds of having ≥2 childhood neurobehavioral disorders compared with children who were not exposed to SHS. Boys had a significantly higher risk. Older children, especially those aged 9 to 11 years, and those living in households with the highest poverty levels were at greater risk. In absolute terms, 274 100 excess cases in total of these 3 disorders could have been prevented if children had not been exposed to SHS in their homes.

The findings of the study, which are associational and not necessarily causal, underscore the health burden of childhood neurobehavioral disorders that may be attributable to SHS exposure in homes in the United States.