title: Effect of environmental exposure to lead and tobacco smoke on inattentive and hyperactive symptoms and neurocognitive performance in children.
abstract: BACKGROUND
  The present study assessed the association between blood lead and urinary cotinine levels and inattentive and hyperactive symptoms and neurocognitive performance in children.
  
  
  METHODS
  A total of 667 children (age range 8-11) were recruited from nine schools in five Korean cities. The teachers and parents completed the Korean version of the Attention-deficit/hyperactivity disorder Rating Scales (K-ARS), and the children performed neurocognitive tests. Blood lead and urinary cotinine levels were then measured.
  
  
  RESULTS
  The inattentive, hyperactive, and total scores of the teacher-rated K-ARS were positively associated with blood lead level, and the results of the continuous performance test (CPT), Stroop Color-Word Test, and Children's Color Trails Test were inversely associated with urinary cotinine level when controlled for age, gender, father's educational level, maternal IQ, child's IQ, residential area, birth weight, and cotinine (for lead) or lead (for cotinine). The association between blood lead level and commission errors score on the CPT disappeared when the effect of urinary cotinine level was controlled.
  
  
  CONCLUSIONS
  These findings indicate that environmental exposure to tobacco smoke in children is associated with poor neurocognitive performance, and low levels of lead are associated with inattention and hyperactivity symptoms.
authors.affiliation: Division of Child and Adolescent Psychiatry, Department of Neuropsychiatry, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Soo-Churl
authors.initials: SC
authors.lastname: Cho
authors.forename: Boong-Nyun
authors.initials: BN
authors.lastname: Kim
authors.forename: Yun-Chul
authors.initials: YC
authors.lastname: Hong
authors.forename: Min-Sup
authors.initials: MS
authors.lastname: Shin
authors.forename: Hee Jeong
authors.initials: HJ
authors.lastname: Yoo
authors.forename: Jae-Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Soo-Young
authors.initials: SY
authors.lastname: Bhang
authors.forename: In Hee
authors.initials: IH
authors.lastname: Cho
authors.forename: Hyo-Won
authors.initials: HW
authors.lastname: Kim
mesh_terms: D000704:Analysis of Variance; D001289:Attention Deficit Disorder with Hyperactivity / Q000097:blood / Q000453:epidemiology* / Q000652:urine; D015984:Causality; D002648:Child; D003072:Cognition Disorders / Q000097:blood / Q000453:epidemiology* / Q000652:urine; D003367:Cotinine / Q000652:urine*; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007723:Korea / Q000453:epidemiology; D007854:Lead / Q000097:blood*; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D017678:Sex Distribution; D014028:Tobacco Smoke Pollution / Q000706:statistics & numerical data*
chemical_list: D014028:Tobacco Smoke Pollution; D007854:Lead; D003367:Cotinine