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

Aim-To test the hypothesis that children with behavioural and/or developmen tal problems have significantly higher blood lead concentrations than the g eneral childhood population. Methods-Blood samples were taken from 69 children with behavioural and/or d evelopmental problems and 136 controls (children admitted for elective day case surgery under general anaesthetic). Blood lead estimations were carrie d 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 acro ss the group (mean(geometric) lead concentrations: 40.7 (cases), 29.2 (cont rols), ratio of the means(geometric) 1.35 (95% CI 1.17, 1.58)) and the prop ortion of children with lead concentrations above those commonly defined as "toxic"-that is, 100 mug/1 (12% (cases), 0.7% (controls); p < 0.001). Mult iple linear regression suggested that this difference was not explained by differences in age, sex, or socioeconomic status of the two comparison grou ps. Conclusions-Children with behavioural and/or developmental problems are mor e likely to have significantly higher blood lead concentrations than the ge neral childhood population. Lead, a known and more importantly, a treatable neurotoxin, would further contribute to the impairment suffered by these c hildren. We argue that this group of children should be routinely screened for lead.