Hair Heavy Metal Contents in Mentally Retarded Children IV: In Association with Copper

Kim, Doohie; Nam, Sang Soong; Park, Soon Woo

Abstract

The relationship between copper content in scalp hair and mental retardation was investigated. Samples of scalp hair were collected from 297 mentally retarded children who were students in one of two schools providing special educational services, one, consisted of children living in an orphan home, the other, children living with parents. For comparison, 117 scalp hair samples were collected from the children who had got average or above average academic achievement in a regular elementary school. Hair samples were taken from the nape of the neck and the copper content was determined by an atomic absorption spectrophotometer (IL 551). There was no statistically significant difference in scalp copper levels across different age groups except female orphan group, but no trend or correlation between copper contents and age was found. The hair copper contents of the group accompanied by Down's syndrome and unknown group were significantly lower than that of control group in both sex, and in the case of accompanied by epilepsy or autism, lower than control group in male. Although the results of this study show no evidence that mental retardation has owed to copper deficiency, the possibility of copper deficiency in their fetal or infant age could not be ruled out. Thus further study is needed to determine whether mental retardation could be attributed to copper deficiency. through the examinations about their living environments, dietary pattern, eating habit and the impact of copper deficiency on brain development.