Lead poisoning risk determination in a rural setting

Objectives. To determine the prevalence of elevated blood lead levels among children living in a rural area and to determine the effectiveness of the Centers for Disease Control and Prevention (CDC) Lead Risk Assessment Questionnaire and additional questionnaire items in correctly identifying rural children having elevated blood lead levels. Research Design. Comparison of results of a questionnaire that is intended to identify children as being at low or high risk for lead poisoning with children's blood lead levels. Setting. The three practice sites of the only pediatric group in a rural county of upstate New York. Patients. A consecutive sample of 705 children ages 6 to 72 months who were seen for health supervision visits between June and September 1993. Results. Sixty-nine percent of the children were considered to be at high risk for lead poisoning by the CDC questionnaire. Overall, 8.4% of the children in the study had blood lead levels of 10 μg/dL (0.48 μmol/L) or higher, and 2.1% had blood lead levels of 15 μg/dL (0.72 μmol/L) or higher. No significant difference was noted between the percentages of high- and low-risk children who had elevated blood lead levels. To devise a more effective lead risk assessment tool for children in this setting, the two items from the CDC questionnaire and the two additional items that had the greatest predictive utility were combined to form a short alternative questionnaire. The alternative questionnaire thus consisted of items concerning whether the child has a sibling or playmate with lead poisoning, whether the child lives near an industry that potentially may release lead, whether the child lives in rented or owner-occupied housing, and whether the child has a parent who is a migrant farm worker. Children categorized as high risk with the alternative questionnaire were much more likely to have elevated blood lead levels than those who were categorized as low risk. The alternative questionnaire was very effective in correctly identifying children with elevated blood lead levels. Eighty-eight percent of children having blood lead levels of 10 μg/dL or higher and 100% of children having blood lead levels of 18 μg/dL or higher were classified as high risk by the questionnaire. Children classified as low risk were very unlikely to have elevated blood lead levels; 98% of low-risk children had blood lead levels of less than 10 μg/dL, and 100% had blood lead levels of less than 15 μg/dL. Conclusions. These results suggest that the CDC lead risk assessment questionnaire is of limited benefit in identifying rural children with blood lead levels 10 μg/dL or higher or 15 μg/dL or higher. An alternative questionnaire, however, seems to have marked clinical utility for identifying rural children with elevated blood lead levels.