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Last Edited: 9/19/2005

Childhood lead clustering in Alameda County
09/2005 -

Questions persist about whether most cases of elevated blood lead levels in children (EBLLs, >=10 ėg/dL) come from a few small localized geographic areas or are more widely spread. Answers to these questions have the potential to inform outreach, screening, and evaluation efforts focused on childhood lead poisoning. The California Childhood Lead Poisoning Prevention Branch is collaborating with EHIB to evaluate this question by examining cases of EBLLs compared to non-EBLLs (< 10 ėg/dL) in Alameda County, CA, using data reported to the state by Children's Hospital of Oakland. This hospital serves as a pediatric phlebotomy site for a large number of local providers, and has been reporting all blood lead results since the early 1990s. We will use a focused test of geographical clustering (Kulldorff's spatial scan statistic), comparing the spatial distribution of EBLLs to non-EBLLs, and calculating the sensitivity, specificity, and positive predictive value of identified clusters. Demographic factors will also be examined to determine whether they can explain any observed clustering.