Korean J Prev Med.  1989 Jun;22(2):215-222.

Hair Heavy Metal Contents in Mentally Retarded Children II: In Association with Cadmium and Zinc

• Park SW
• Lee JY
• Kim D

Abstract

The relationship between cadmium level and mental retardation was investigated. The 297 subjects with mental retardation were drawn from two schools providing special educational services, one, consisted of children living in an orphan home, another, children with parents. The 117 control subjects were drawn from whom had got average or above average academic achievement in a general elementary school. Hair sample was taken from the nape of the neck and the cadmium and zinc analysis were carried out on an atomic absorption spectrophotometer (IL 551). Children in the retarded group had significantly higher cadmium levels compared with control but not in zinc levels. There was no relationship between metal concentrations and age except control male group, which showed significant positive linear relationship in zinc, and there was no difference between sex in both metal except the male orphan group in cadmium. In the orphan group, there was relationship between severity of retardation and cadmium concentration in both sex but not in retarded children with parents. No difference in cadmium levels between the group with Down's syndrome, one of causes of mental retardation and the control group suggested the cadmium as a possible cause of mental retardation. In the case of accompanying autism, zinc level was significantly lower than that of other accompanying disease. Although not establishing an etiologic relationship, findings of this study suggest that there are some influences of cadmium on mental retardation, and call for a continuing study.

MeSH Terms

Absorption
Autistic Disorder
Cadmium*
Child*
Child, Orphaned
Down Syndrome
Hair*
Humans
Intellectual Disability
Male
Mentally Disabled Persons*
Neck
Parents
Zinc*
Cadmium
Zinc