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

Abstract

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.sub.geometric] lead concentrations: 40.7 (cases), 29.2 (controls), ratio of the [means.sub.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 [micro]g/1 (12% (cases), 0.7% (controls); p[less than]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.

Keywords: developmental problems; behavioural problems; lead; screening

Lead contaminated particles can enter the body through inhalation and ingestion. Children absorb over three times as much lead as adults and are at greatly increased risk through increased mouthing behaviours such as chewing objects and sucking their fingers. Lead is a known neurotoxin in children and has been shown to adversely affect cognitive functioning and development, [1-3] with no lower threshold for blood lead concentration below which these effects do not occur. [4]

Environmental policies and legislation have been successful in reducing community lead exposure; as a result it is not considered to be an important public health problem in the UK. [5] However, in the USA there is greater public concern over lead and extensive lead screening programmes have been carried out there since the early 1960s. [6] The Centers for Disease Control, Atlanta, generally recommends that children first receive blood lead screening at 1 year of age with additional …