Association between early lead exposure and externalizing behaviors in adolescence: A developmental cascade

• Published in: Environmental research Vol. 178; p. 108679
• Main Authors: Desrochers-Couture, Mireille, Courtemanche, Yohann, Forget-Dubois, Nadine, Bélanger, Richard E., Boucher, Olivier, Ayotte, Pierre, Cordier, Sylvaine, Jacobson, Joseph L., Jacobson, Sandra W., Muckle, Gina
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.11.2019; Elsevier
• Subjects: Adolescent; Adolescent Behavior; Attention Deficit and Disruptive Behavior Disorders - epidemiology; Binge drinking; Cannabis use; Child; Child Behavior; Child Behavior Disorders; Children and adolescents; Environmental Exposure - statistics & numerical data; Externalizing behaviors; Female; Humans; Lead; Lead - metabolism; Life Sciences; Longitudinal Studies; Male; Quebec - epidemiology; Substance-Related Disorders - epidemiology; Quebec; Binge drinking; Lead; Cannabis use; Children and adolescents; Externalizing behaviors
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2019.108679

Lead (Pb) exposure is associated with adverse neurological development. Most notably, it has been observed through externalizing behavior symptoms, as observed among Inuit children from northern Québec. Evidence for a persistent neurological impact of early Pb exposure later in life is however scarce. Pb exposure may initiate a developmental cascade that increases the risk of long-term behavior problems. Testing for direct associations between childhood Pb concentrations and adolescent externalizing symptoms and substance use, as well as indirect associations through childhood behavior assessments. The study sample is a longitudinal cohort of Inuit children (n = 212) followed since birth. Blood Pb concentrations were measured during childhood (median age = 11.4 years) and adolescence (median age = 18.5 years). Externalizing/inattentive behavior were teacher-assessed through the Teacher Report Form and the Disruptive Behavior Disorders Rating Scale for children. At the adolescence follow-up, behavior problems were self-reported by filling Achenbach's Youth Self-Report, the Barkley Adult ADHD-IV Rating Scale, and the Diagnostics Interview Schedule for Children. Adolescent substance use was also self-assessed through the DEP-ADO. Direct and indirect associations of child Pb concentrations with adolescent outcomes were tested through mediation models. Child blood Pb concentrations were not directly associated with any adolescent outcomes. On the contrary, childhood Pb exposure was indirectly associated, through childhood externalizing behavior assessments, with adolescent externalizing behaviors, binge drinking, and cannabis use. These indirect associations held after controlling for adolescents’ concurrent Pb blood concentrations. Our results highlight the indirect but lasting effects of child Pb exposure on adolescent behavior problems, and the importance of childhood externalizing behavior in this relationship. Adverse early-life environment put children on a riskier developmental trajectory, increasing their likelihood of lifelong psychological, social and health problems. •Child Pb associated with adolescent externalizing behavior and substance use.•These associations mediated by child externalizing behaviors.•Early-life impairments may put children on a riskier developmental trajectory.