Racial differences in the effects of postnatal environmental tobacco smoke on neurodevelopment.

Objectives: We used the 2001-2004 National Health and Nutrition Examination Survey to examine the association between postnatal environmental tobacco smoke exposure, measured as serum cotinine levels, and attention-deficit/hyperactivity disorder (ADHD) among children 4 to 15 years of age. We further investigated the interactions of race and serum cotinine levels with ADHD.

Methods: Logistic regression models were used to evaluate associations.

Results: This study found that the prevalence of ADHD increased as blood cotinine levels increased. The effects of blood cotinine levels on ADHD differed according to race. Compared with children of the same racial group with the lowest blood cotinine levels, the odds ratios were 2.72 (95% confidence interval: 1.25-5.93) for Mexican American children and 5.32 (95% confidence interval: 1.55-18.3) for children in other racial groups with the highest blood cotinine levels, with controlling for the effect of maternal smoking during pregnancy. However, no significant associations between blood cotinine levels and ADHD were observed among non-Hispanic white or non-Hispanic black children.

Conclusions: The findings of this study underscore the possibility of racial disparities in the effects of environmental tobacco smoke on behavioral problems in children. These findings warrant further investigation.