Environmental noise exposure and emotional, aggressive, and attention-deficit/hyperactivity disorder-related symptoms in children from two European birth cohorts

Background: Environmental noise exposure is increasing but limited research has been done on the association with emotional, aggressive, and attention-deficit/hyperactivity disorder (ADHD)-related symptoms in children. Objective: To analyze the association between prenatal and childhood environmental noise exposure and emotional, aggressive, and ADHD-related symptoms in children from two European birth cohorts. Methods: We included 534 children from the Spanish INMA-Sabadell Project and 7424 from the Dutch Generation R Study. Average 24 h noise exposure at the participants' home address during pregnancy and childhood periods were estimated using EU maps from road traffic noise and total noise (road, aircraft, railway, and industry). Symptom outcomes were assessed using validated questionnaires: Strengths and Difficulties Questionnaire, Child Behavioral Checklist, ADHD Criteria of Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition List, and Conner's Parent Rating Scale-Revised at 4, 7 and 9 years (INMA-Sabadell cohort) and 18 months, 3, 5, and 9 years (Generation R Study). Adjusted linear mixed models of prenatal and repeated childhood noise exposure with repeated symptom outcomes were run separately by cohort and overall estimates were combined with random-effects meta-analysis. Results: Average prenatal and childhood road traffic noise exposure levels were 61.3 (SD 6.1) and 61.7 (SD 5.8) for INMA-Sabadell and 54.6 (SD 7.9) and 51.6 (SD 7.1) for Generation R, respectively. Prenatal and childhood road traffic noise exposure were not associated with emotional, aggressive, or ADHD-related symptoms. No heterogeneity was observed between cohorts and results were comparable for total noise exposure. Conclusions: No association was observed between prenatal or childhood road traffic or total noise exposure and symptom outcomes in children. Future studies should include a more comprehensive noise exposure assessment considering noise sensitivity and noise exposure at different settings such as work for pregnant women and school for children.