Should children with developmental and behavioural problems be routinely screened for lead?

AIM To test the hypothesis that children with behavioural and/or developmental problems have significantly higher blood lead concentrations than the general childhood population. METHODS Blood samples were taken from 69 children with behavioural and/or developmental problems and 136 controls (children admitted for elective day case surgery under general anaesthetic). Blood lead estimations were carried out using graphite furnace atomic absorption RESULTS Children with behavioural and/or developmental problems had higher lead concentrations than controls, both in terms of their distribution across the group (mean(geometric) lead concentrations: 40.7 (cases), 29.2 (controls), ratio of the means(geometric) 1.35 (95% CI 1.17, 1.58)) and the proportion of children with lead concentrations above those commonly defined as "toxic"-that is, 100 microg/l (12% (cases), 0.7% (controls); p < 0.001). Multiple linear regression suggested that this difference was not explained by differences in age, sex, or socioeconomic status of the two comparison groups. CONCLUSIONS Children with behavioural and/or developmental problems are more likely to have significantly higher blood lead concentrations than the general childhood population. Lead, a known and more importantly, a treatable neurotoxin, would further contribute to the impairment suffered by these children. We argue that this group of children should be routinely screened for lead.