The geometric mean concentrations of MEHP, MEOP, and MBP in clinic-referred children with ADHD in this study (45.60, 43.82, and 68.03 μg/g, respectively) were higher than those in children and adolescents aged 6 to 19 years in the previous community study of Korea (25.79, 22.20, and 45.60 μg/g, respectively) [33] and those in 6–15-year-old children in population-based survey in the USA (30.6, 21.2, and 30.2 μg/g, respectively) [19]. Here, MBP is linked to attention deficit-hyperactivity disorder.