The Role of Air Nicotine in Explaining Racial Differences in Cotinine Among Tobacco-Exposed Children

Abstract

Objective:African-American children have higher rates of tobacco-associated morbidity. Few studies have objectively measured racial differences in the exposure of children to tobacco smoke. The objective of this study was to test whether African-American children have higher levels of cotinine compared to white children while accounting for ambient measures of tobacco smoke.Setting:Community-based sample of asthmatic children (n = 220) enrolled in an environmental tobacco smoke (ETS) reduction trial.Participants:A biracial sample (55% African American) of children with asthma aged 5 to 12 years who were routinely exposed to ETS.Measurements:We measured cotinine levels in serum and hair samples at baseline, 6 months, and 12 months. We measured the level of ETS exposure over a 6-month period by placing air nicotine dosimeters in the homes of the children at baseline and at 6-month study visits.Results:African-American children had significantly higher levels of cotinine at all time points in the study. At the 12-month visit, African-American children had higher levels of serum cotinine (1.39 μg/dL vs 0.80 μg/dL, p = 0.001) and hair cotinine (0.28 ng/mg vs 0.08 ng/mg, p < 0.0001) when compared with white children. In a repeated-measures analysis, African-American children had significantly higher levels of serum cotinine (β = 0.28, p = 0.04) and hair cotinine (β = 1.40, p < 0.0001) compared with white children. Air nicotine levels and housing volume were independently associated with higher levels of cotinine.Conclusions:Among children with asthma, African-American children have higher levels of serum and hair cotinine compared with white children.