Risk Factors and Geographic Hot Spots for Childhood Lead Poisoning in Tennessee

Background: Childhood lead poisoning can cause serious health effects in children and is a public health concern in the United States. In 2012, the Centers for Disease Control and Prevention lowered the blood lead reference level for childhood lead poisoning from 10 µg/dL to 5 µg/dL.

Objective: The purpose of this study was to identify risk factors and high-risk populations at the census tract level in Tennessee associated with the new reference level.

Methods: A retrospective cross-sectional design was used with secondary data from the U.S. Census Bureau and the Tennessee Department of Health (TDH).  Health records of children under the age of 6 years with a BLL reported to TDH in 2009-2013 were included (N = 7,302). The variables examined were gender, age at time of test, race, ethnicity, pre-1950 housing, and poverty level.  Logistic regression and Getis-Ord Gi* spatial analyses were performed. 

Results: African Americans have significantly higher odds for lower blood lead levels (odds ratio [OR] = 2.07, 95% CI [1.60, 2.68]). Ages 4 and 5 (OR = 0.64, 95% CI [0.45, 0.90]; OR = 0.62, 95% CI [0.42, 0.91]), compared to ages <1 through 3 years, and the highest quintile of pre-1950 housing (OR = 0.72 (95% CI [0.56, 0.93]) have significantly lower odds for lower blood lead levels.  According to the Getis-Ord Gi* analysis, Memphis and northeast Tennessee were statistically significant high-risk areas for the new reference level, while the highest BLLs were characterized by unique high-risk areas in southeast/southcentral Tennessee and northwest Tennessee.

Conclusion: Understanding the risk factors and areas of greatest risk will enable the TDH to develop targeted strategies for achieving the Healthy People 2020 goals for childhood lead poisoning.