Exposure to Lead and Attentional and Behavioral Problems in Attention Deficit Hyperactivity Disorder

It is now generally accepted that lead low doses may influence behavioral and attentional problems in children. The selection of a treatment approach depends on a proper assessment of the cause of the problem. This study was carried out to investigate the relationship between exposure to lead and behavioral and attentional problems in attention deficit hyperactivity disorder(ADHD).

The participants were 62 boys, 6 to 12 years of age with ADHD. Children with probable causes of attentional or behavioral problems other than lead contamination were excluded from the study. Various aspects of behavioral problems were measured using questionnaires for parents and teachers. Attentional problems were measured with TOVA(The Test Of Variability of Attention). As an assessment of body lead burden, lead concentration in blood was measured.

Mean lead concentration in blood was 3.39 1.32µg/dl. Correlations between lead concentration in blood and the possible confounding factors were not significant. The results were same as that of lead concentration in attentional and behavioral problems. Lead concentration was significantly correlated with the scores of TOVA : omission error(r=0.34, p<0.1) ; commission error(r=0.43, p<0.05) ; and variation(r=0.34, p<0.1). Correlations between lead concentration and social withdrawal subscale of CBCL were significant(r=0.33, p<0.01).

It appears that some link between low-level exposure to lead and performances exist.