Identifying High-Risk ZIP Codes for Childhood Lead Exposure: A Statewide ZCTA-Level Priority List for North Carolina

Abstract

Background: Research has consistently shown that there is no safe blood lead level (BLL) for children. Despite progress in lead poisoning prevention, lead exposure remains a persistent threat to the health and neurological development of children. To identify high-risk ZIP codes for use by families and health care providers for the entire state of North Carolina, we developed a risk model using ZIP Code Tabula-tion Area (ZCTA)-level census data.

Methods: We obtained all available BLL testing data from the North Carolina Department of Health and Human Services for the years 2010-2015 via data use agreement. We fit a multivariable regression model with the ZCTA-level mean of log normalized BLLs as the de-pendent variable and ZCTA-level census data for known risk factors of childhood lead exposure as predictors. We used this model to create a priority risk categorization.

Results: We organized ZCTAs into 20 quantiles, or priority risk categories, that can be used in local and statewide screening programs. The first six (of 20) quantiles were identified as particularly high-risk areas for childhood lead exposure.

Limitations: Because BLL testing is not universal, the BLL testing data used in this study are likely biased toward those most at risk for lead exposure.

Conclusion: This study demonstrates the utility of ZCTA-level census data in identifying high-risk ZIP codes for childhood lead exposure, which can be used to ensure that the highest-risk children are tested in a timely manner. This approach can be replicated to address lead exposure nationally.

Keywords: Duke Health; Duke University; North Carolina; Rashida Callender; blood lead levels; census data; health policy; lead poisoning; original research.