Psychometrical performance of young belgian boys with unusual lead absorption : A pilot study

Two groups of boys, 4-5 years old, living respectively in a high and low lead intake risk areas (Verviers and Liege) have been compared for two intelligence scales, for the developmental test of the visual perception, for two French vocabulary tests and for the hair lead content. Possible psychological or sociological bias have been controlled by the matching of boys for familial variables and by exclusion of children with a non acceptable medical and psychological previous history.
The results show a higher geometric mean for the hair lead concentration in the Verviers children. The mean scores of the Wechsler full scale IQ and the vocabulary tests do not differ significantly in the investigated groups. The performance subtests of the intelligence scales however give different results at the usual 5% level. The small size of the samples examined in this pilot study precludes any conclusion about the causality or the strength of the association.