Doctor of Philosophy (PhD)
Environmental Health, Occupational Health, and Toxicology
Dr. Chandran Achutan
Dr. Eleanor Rogan
Dr. Lynette Smith
Dr. Dejun Su
Childhood exposure to lead is known to cause a host of adverse health effects in children, with no safe blood lead level indicated. Environmental lead contamination is prevalent throughout the United States and remains a threat to the healthy development of children living in these areas, including children in Omaha, Nebraska. The overall objectives of this dissertation were to characterize potential sources of lead in the community – where children play and where children live through the use of environmental exposure sampling. This dissertation also provides insight into current Nebraska children's blood lead levels and identifies local populational attributes that may predispose children to lead exposure and subsequent adverse health outcomes.
The first study quantified soil and air concentrations of lead in Omaha, Nebraska parks. Home to one of the largest historically known lead-contaminated Superfund sites, local metro parks were examined both within the historically designated Superfund program area and outside of this area (n=60) using the EPA's soil sampling protocol. The geometric mean and median soil lead concentrations among 30 Omaha Lead Superfund site’s parks were 28.3 parts per million (ppm) and 33.1 ppm, respectively. These two statistics were significantly higher than those in non-Superfund site parks (geometric mean=12.8, median=14.0, p
The second study assessed residential indoor lead dust concentrations in Omaha and determine the potential determinants of elevated indoor lead dust concentrations. Data with windowsill and floor lead dust concentrations from 350 eligible households was analyzed. Our findings reaffirmed the existing indoor lead exposure issue in Omaha, as approximately one-third of participated homes had either windowsill or flood lead dust concentrations that failed to meet the EPA standards. Elevated indoor lead dust concentrations were more common among African American families (adjusted odds ratio [OR] =2.22; 95%CI: 1.18, 4.18) and the families that adults without any health insurance coverage (adjusted OR=1.90; 95%CI: 1.04, 3.46). Additionally, homes built before 1950 (adjusted OR=6.21; 95%CI: 2.32, 16.63) and inside the Omaha Lead Superfund site with a soil lead level exceeded 400 ppm (adjusted OR=2.45; 95%CI: 1.16, 5.18) had higher odds of having elevated indoor lead dust concentration.
The final study evaluated children's blood lead levels in the Greater Omaha area and the other areas in Nebraska by using electronic health records. Indication of elevated BLL (≥5 μg/dL) was used to quantify the prevalence of children with elevated blood lead levels in both areas. Findings indicated the incidence of elevated blood lead levels has decreased from 25% in the early 1990s to approximately 3%, among children living in the Greater Omaha area. However, the statistics suggested childhood lead poisoning may still be a public health problem in Omaha, NE, as the incidence of elevated childhood blood lead was higher than the national surveillance level. Only a few children's blood lead tests (
Collectively, these studies sought to identify current and historical sources of lead exposures among children and the adverse effect childhood lead exposures can have on their healthy development. Using environmental exposure sampling and electronic health records data on BLLs of children, we provide evidence that lead exposures may be declining, but the burden of lead exposure on a child's health remains prevalent in Omaha, NE. The highlight of this dissertation is that elevated indoor lead dust concentration is prevalent in Omaha, NE, especially for those who with certain lower socioeconomic status. These findings are evidence of environmental justice issues and health disparities in childhood lead exposure in Omaha, NE. Therefore, we recommended several plans of future lead related research, policy making, and management plans in Omaha, NE. With collaborative efforts through partnerships between health departments, academic researchers, and community members, we hope to reduce and eliminate lead exposure so that a better living environmental can be provided to our children and community.
Qin, Zijian, "Investigation of Environmental Lead Exposures in Children at A Midwestern City with Superfund Site" (2021). Theses & Dissertations. 577.
Available for download on Sunday, August 20, 2023