Passive environmental exposure to cocaine in Canadian children

Background: Hair testing is commonly used to confirm potential drug exposure in children living with drug users, as well as abstinence in their caregivers. Objective: To examine differences across pediatric age groups in the relationship between caregiver use of cocaine and cocaine exposure in children. Methods: We determined concentrations of cocaine and its metabolite, benzoylecgonine, in the hair of 19 child-caregiver pairs to estimate the pattern of exposure of the children according to age; concentrations in the caregivers' hair were used as a surrogate marker for the intensity of environmental exposure. Cocaine and benzoylecgonine concentrations in hair were determined by immunoassay. Results: A significant correlation was observed between cocaine concentrations in the hair of infants and their caregivers (Spearman rho = 0.87; p = 0.005; n = 8), and the absence of a correlation in older children. These results suggest that environmental exposure plays an important role in the accumulation of cocaine in the hair of infants. Conclusion: Measurement of cocaine hair concentrations can allow estimation of the degree of environmental drug exposure in young children. Infants seem to have a disproportionately increased risk for systemic exposure, compared with older children.