Phthalates Exposure and Attention-Deficit/Hyperactivity Disorder in School-Age Children
Received 23 February 2009; received in revised form 16 July 2009; accepted 22 July 2009. published online 14 September 2009.
Background
Very few studies have examined the association between attention-deficit/hyperactivity disorder (ADHD) and phthalate exposure in humans. The aim of this study was to investigate the impact of phthalates on symptoms of ADHD in school-age children.
Methods
A cross-sectional examination of urine phthalate concentrations was performed, and scores on measures of ADHD symptoms and neuropsychological dysfunction with regard to attention and impulsivity were obtained from 261 Korean children, age 8–11 years.
Results
Mono-2-ethylheyl phthalate (MEHP) and mono-2-ethyl-5-oxohexylphthalate (MEOP) for metabolites of Di-2-ethylhexylphthalate (DEHP) and mono-n-butyl phthalate (MNBP) for metabolites of dibutyl phthalate (DBP) were measured in urine samples. The mean concentrations of MEHP, MEOP, and MNBP were 34.0 μg/dL (SD = 36.3; range: 2.1–386.7), 23.4 μg/dL (SD = 23.0; range: .75–244.8), and 46.7 μg/L (SD = 21.4; range: 13.2–159.3), respectively. After adjustment for covariates, teacher-rated ADHD scores were significantly associated with DEHP metabolites but not with DBP metabolites. We also found significant relationships between the urine concentrations of metabolites for DBP and the number of omission and commission errors in continuous performance tests (CPT) after adjustment for covariates.
Conclusion
The present study showed a strong positive association between phthalate metabolites in urine and symptoms of ADHD among school-age children.
aDivision of Child & Adolescent Psychiatry, Department of Psychiatry and Institute of Human Behavioral Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
bDepartment of Psychiatry, Seoul National University Bundang Hospital, Seong-nam, Republic of Korea
cDepartment of Preventive Medicine, Seoul National University College of Medicine and Institute of Environmental Medicine, SNUMRC, Seoul, Republic of Korea
dDepartment of Psychiatry, Ulsan University Hospital, Ulsan, Republic of Korea
Address correspondence to Yun-Chul Hong, M.D., Ph.D., Department of Preventive Medicine, Seoul National University College of Medicine and Institute of Environmental Medicine, SNUMRC, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Republic of Korea
ABSTRACT