IS THERE LEAD IN THE SUBURBS - RISK ASSESSMENT IN CHICAGO SUBURBAN PEDIATRIC PRACTICES

Objective. This study was designed to determine: (1) the prevalence of elevated blood lead (BPb) levels (BPb greater than or equal to 10 mu g/dL) in Chicago suburban children attending Pediatric Practice Resear ch Group practices at 12 and 24 months of age, and (2) the efficacy of the Centers for Disease Control and Prevention (CDC) and Illinois lea d exposure risk assessment questions. Methods. Parents bringing their 1- and 2-year-old children for health supervision visits at pediatric practices completed questionnaires. BPb levels were drawn on children. Both questionnaire and an analyzable BPb level were obtained on 1393 subjects (79.2%). Results. Only 2.1% of our sample had a venous BPb le vel greater than or equal to 10 mu g/dL (0.48 mu mol/L); no subjects h ad a level greater than or equal to 30 mu g/dL (1.45 mu mol/L). The CD C risk assessment questions had a sensitivity of .69 and specificity o f .70. Due to the low prevalence of elevated BPb levels in this sample , CDC and Illinois screening strategies had high negative predictive v alues (.99) and low positive predictive values (.05 and .04, respectiv ely). However, some of the subjects with BPb levels greater than or eq ual to 10 mu g/dL were not at high risk by CDC and Illinois screening questions; 9 of 29 subjects with elevated lead levels (31%) did not re spond affirmatively to any CDC risk assessment questions. The question best predicting an elevated BPb was the determination that the house the child lives in was built before 1960 (sensitivity = .83, specifici ty = .67). This question is not currently included in CDC or Illinois screening strategies. Screening based on the single question ''Was you r house built before 1960?'' would have missed only five (17%) of the children with BPb levels greater than or equal to 10 mu g/dL. Three of these five children were among the 17.1% of 1-year-olds and 26.3% of 2-year-olds in our sample who had moved. Conclusions. In this sample, children living in houses built before 1960 should be considered at hi gh risk for high-dose lead exposure. Due to the high mobility of our s ample, phrasing the question to include lifetime exposure (ie, Has you r child ever lived in a house built before 1960?) should also be consi dered. Selective BPb testing of high-risk children in low-prevalence s uburban areas using this question would miss few children with elevate d BPb. Useful risk assessment questions in other areas and other popul ations may differ.