Association between blood lead levels (<5 μg/dL) and inattention-hyperactivity and neurocognitive profiles in school-aged Korean children.
OBJECTIVE
The association between low blood lead levels (<5 μg/dL) and the inattention-hyperactivity symptoms and neurocognitive profiles of school-aged Korean children was investigated.


METHODS
We measured blood lead levels in 256 Korean children aged 8-10 years. Teachers completed the Attention-Deficit Hyperactivity Disorder Rating Scale (T-ARS)-IV to assess inattentive and hyperactive symptoms. Parents completed the Korean version of the Learning Disability Evaluation Scale (K-LDES). Children performed neurocognitive tests [The Continuous Performance Test (CPT), the Children's Color Trails Test, and the Stroop Color and Word Test (SCWT)].


RESULTS
A linear regression analysis indicated that the blood lead concentrations were associated with the inattention scores [B=4.8, S.E.=1.6, 95% confidence interval (CI): 1.5-8.0], the hyperactivity subscores (3.1, 1.4, 0.3-5.9), and the total score (7.9, 2.9, 2.1-13.6) on the T-ARS; the number of omission errors on the CPT (20.6, 7.1, 6.5-34.6); the listening (-1.4, 0.7, -2.8 to -0.1), reading (-2.1, 0.7, -3.4 to -0.7), writing (-2.0, 0.7, -3.4 to -0.6), spelling (-2.2, 0.7, -3.7 to -0.7), and calculating (-1.8, 0.7, -3.1 to -0.4) scores on the K-LDES; and the color-word score on the SCWT (-6.7, 3.4, -13.3 to -0.1). A logistic regression analysis indicated that the probability of inattentive and hyperactive symptoms was increased with higher blood lead levels in boys with an odds ratio of 2.768 [B=1.018, S.E.=0.487, p=0.036, 95% CI: 1.066-7.187].


CONCLUSIONS
This study suggests that even low blood lead levels (<5 μg/dL) are associated with inattentive and hyperactivity symptoms and learning difficulties in school-aged children.
Kim
Yeni
Y
Division of Child & Adolescent Psychiatry, Department of Psychiatry and Institute of Human Behavioral Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
Cho
Soo-Churl
SC
Kim
Bung-Nyun
BN
Hong
Yun-Chul
YC
Shin
Min-Sup
MS
Yoo
Hee-Jeong
HJ
Kim
Jae-Won
JW
Bhang
Soo-Young
SY
D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology*; D002648:Child; D004781:Environmental Exposure / Q000706:statistics & numerical data; D004785:Environmental Pollutants / Q000097:blood*; D005260:Female; D006801:Humans; D007723:Korea / Q000453:epidemiology; D007854:Lead / Q000097:blood*; D007859:Learning Disabilities / Q000453:epidemiology*; D008297:Male; D009483:Neuropsychological Tests; D011153:Population; D012574:Schools
D004785:Environmental Pollutants; D007854:Lead