PhD, University of Cincinnati, 2009, Medicine : Neuroscience/Medical Science Scholars Interdisiplinary

INTRODUCTION: Lead is a potent environmental toxicant. Childhood lead exposure is associated with persistent cognitive and behavioral deficiencies, suggesting underlying neuroanatomic changes. This dissertation is an investigation of the effects of childhood lead exposure on young adult gray matter volume and white matter structure. METHODS: We investigated a subset of the long-running Cincinnati Lead Study, a prospective birth cohort study investigating the effects of environmental lead exposure on a primarily black, urban inner-city cohort. Participants received 23 serial assessments of blood lead concentration during childhood, high-resolution volumetric magnetic resonance imaging at approximately 21 years of age, and diffusion tensor imaging at approximately 24 years of age. Associations between gray matter volume and mean childhood blood lead, and yearly mean blood lead levels from years 1 to 6, were investigated by adjusted voxel-wise multiple regression analysis using voxel-based morphometry (VBM) techniques. Associations between mean childhood lead levels and white matter diffusivity changes were investigated using adjusted multiple regression analyses. RESULTS: Mean childhood lead levels were associated with significant adult gray matter volume loss, particularly in the frontal lobes, and particularly in men. Analysis of yearly mean blood lead levels revealed that blood levels later in childhood were more strongly associated with adult gray matter volume loss than earlier blood lead levels. The most extensive and significant regions of lead-associated gray matter volume loss were found in the frontal lobes of men associated with lead levels measured later at 5 and 6 years of age. Investigation of white matter diffusivity changes by diffusion tensor imaging analysis revealed widespread changes in fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity. The observed patterns of diffusivity changes was consistent with signific (open full item for complete abstract)

Committee: Kim Cecil PhD (Advisor); Caleb Adler MD (Committee Member); James Herman PhD (Committee Member); Bruce Lanphear MD MPH (Committee Member); M. Douglas Ris PhD (Committee Member); Stephen Woods PhD (Committee Member) Subjects: Health; Neurology; Radiology

PHD, Kent State University, 2021, College of Public Health

Children from resettled refugee families (RRF) in the United States are a vulnerable group for childhood lead poisoning (CLP)-- an environmental hazard with multiple irreversible adverse health effects in children. My dissertation research aimed to assess CLP among children from RRF pre- and post-U.S. resettlement and understand CLP knowledge, attitudes, and practices, and prevention barriers (KAP-B) among Nepali-speaking Bhutanese (NSB) resettled refugee groups in northeast Ohio. Data from the post-resettlement refugee medical screening of 5,661 children resettled in Ohio from 2009 to 2016 were utilized to assess the prevalence of elevated blood lead level (EBLL)—defined as BLL ≥ 5 micrograms per deciliter (µg/Dl)— as a proxy for pre-resettlement exposure. Electronic medical records (EMR) data from an Akron Children's Hospital Outpatient Clinic were used in a retrospective cohort study to assess the incidence of EBLL in a sample of 6,283 children <6 years of age between 2009 to 2015. The primary language spoken at home was used as a proxy to classify children as either being from RRF or being from non-RRF (NRF) categories. A Nepali language questionnaire (KAP-B) was developed and used to assess current knowledge, attitudes, daily household practices, and barriers to prevention measures for CLP among 200 NSB RRF with at least one child ≤ 7 years in northeast Ohio. Overall, 27.1% of RR children <6 years in Ohio had an EBLL at the time of resettlement. Children from RRF from the South-Asian region (Afghanistan, Nepal, Bhutan, and Burma [56.2% - 31.8%]) had the highest EBLL prevalence. Of these, children from Nepali-speaking families had the highest EBLL incidence at 9.67 per 100 person-years. Children from RRF had 11 times the risk of EBLL than nonrefugee children. NSB parents surveyed demonstrated a low level of knowledge regarding CLP and prevention measures. While 80% of respondents lived in pre-1978 houses, only 27.5% perceived their house/neighborhood to (open full item for complete abstract)

Committee: Madhav Bhatta (Committee Chair); Vinay Cheruvu (Committee Member); Maggie Stedman-Smith (Committee Member); P. Cooper White (Committee Member) Subjects: Environmental Health; Epidemiology; Health; Health Education

PHD, Kent State University, 2018, College of Arts and Sciences / Department of Geography

Research focusing on neighborhood effects on health often fails to connect aspects of the neighborhoods which contribute to disparities, and the mechanisms in which social processes and the built environment affects the lives of individuals. The purpose of this dissertation is to explore the neighborhood risks affecting health and well-being for the pediatric population in Akron, Ohio, through novel methods in geospatial technologies. Within the context of injury prevention and childhood lead exposure, I explore factors which impact children living in Akron through the collection, mapping and analysis of data at a granular spatial scale. The first of the three studies is focused on the use of spatial video in assessment of child behaviors and injury surveillance for active school transport immediately before, during and after an intervention (at three time periods) as part of International Walk to School Day at one Community Learning Center (CLC) in Akron, Ohio. This paper analyzes data generated from coding spatial video in a GIS for variables related to child characteristics, activity, location, and the surrounding environment to identify behaviors and aspects of the built environment which may contribute to unintentional injuries during active school transport. The focus of the second study is to investigate aspects of properties that may contribute to lead exposure through the development of an Environmental Lead Index (ELI). Spatial video was coded for the presence of eight variables and summarized to create a number value. Blood lead levels, extracted from the EMR as lead test results, were used to assess the validity of the ELI. Additional insights into the challenges affecting this diverse pediatric population, such as a residential mobility rate over 70 percent, are provided through a descriptive analysis of the study population, which includes a growing immigrant population. The last paper concentrates on the challenges associated with residential m (open full item for complete abstract)

Committee: Andrew Curtis (Committee Chair); Jacqueline Curtis (Committee Member); Eric Jefferis (Committee Member); Eric Shook (Committee Member) Subjects: Environmental Health; Epidemiology; Geographic Information Science; Geography

MS, University of Cincinnati, 2002, Medicine : Environmental Health Sciences

Purpose. The purpose of this research was to determine the practicality of using airborne lead measurements obtained with field portable x-ray fluorescence (XRF) technology to manage worker protection programs. The NITON® XL-700 Series XRF was used to measure airborne lead samples from the U.S. Coast Guard Barque EAGLE while undergoing repairs at the Coast Guard Shipyard. Lead-based paint was used extensively during construction of EAGLE, which was completed in 1936 in Hamburg, Germany. Methods: 47 airborne lead samples were collected in 37 mm cassettes on mixed cellulose ester filters over two weeks. Twenty (20) personal and twenty-seven (27) area samples were obtained. Samples collected during week one were analyzed by XRF the following Sunday, when no work was scheduled on EAGLE. Samples obtained during week two were analyzed daily with field portable XRF. The samples were analyzed using NIOSH Method 7702, Lead by Field Portable XRF to determine lead mass. Using known air volume and lead mass, airborne lead concentration was calculated. To verify instrument performance, the samples were later analyzed by NIOSH Method 7082, Lead by Flame AAS. Results: The range of airborne lead concentrations was 8 to 939 μg/m 3 . With daily monitoring by field portable XRF, airborne lead concentration was reduced 77 percent from week one to week two. The average concentration was 176.9 μg/m 3 during the first week, while the average was 41.3 μg/m 3 during the second. With the exposure data gathered in near real-time, workers reduced concentration by implementing controls including vacuum equipped tools and improved ventilation. On twelve (12) occasions during week one, workers engaged in jobs that produced airborne lead concentrations that exceeded the action level. During week two, when daily monitoring by field portable XRF was instituted, workers exceeded the action level six (6) times. Conclusions: Provided that a sheltered workspace with minimal distractions is available to (open full item for complete abstract)

Committee: Dr. C. Scott Clark (Advisor) Subjects:

PhD, University of Cincinnati, 2015, Medicine: Neuroscience/Medical Science Scholars Interdisciplinary

Lead is a well-known environmental contaminant. The known effects of lead exposure include cognitive and neuropsychological deficits, behavioral abnormalities, organ damage, as well as other developmental consequences. The purpose of this dissertation is to investigate behavioral and developmental consequences of childhood lead exposure in adulthood using Magnetic Resonance Imaging techniques. Participants from the Cincinnati Lead Study were utilized for the purposes of this work. Participants received MRI anatomical and diffusion-weighted scans at approximately age 27 years. Previous MRI scans from age 21 years were also utilized. Measurements of adult criminality and psychopathy were obtained from previous research studies in the CLS for retrospective analyses. Voxel-based analyses were used to determine whether measures of criminality and psychopathy were associated with changes in gray and white matter structures. Voxel Based Morphometry was also used to examine whether childhood lead exposure contributes to increased rates of neurodegeneration in adulthood. The results of this dissertation found that measures of criminality were primarily associated with altered patterns of white matter structure and organization in ascending and descending white matter pathways. Furthermore, sex differences suggest that females display negative patterns of myelination in association with criminality, while males display positive associations. Analyses with the psychopathy data suggest that a combination of volumetric loss in the cerebellar white matter and negative patterns of myelination in the frontal, temporal, and parietal lobes are associated with increased measures of psychopathy. Analysis of sex differences suggest that females display similar patterns as the entire cohort, while males display minimal effects. Finally, the analysis of the influence of childhood lead exposure on the rate of neurodegeneration yielded mixed results. The VBM analysis demonstra (open full item for complete abstract)

Committee: James Eliassen Ph.D. (Committee Chair); Kim Cecil Ph.D. (Committee Member); Kim Dietrich Ph.D. (Committee Member); James Herman Ph.D. (Committee Member); Michael Williams Ph.D. (Committee Member) Subjects: Neurology

Master of Science, The Ohio State University, 2013, Public Health

Objective: This study assessed the relationship between environmental lead exposure and blood lead levels of children living in treated homes in the city of Milwaukee. Methods: The U.S. Department of Housing and Urban Development (HUD) funded a prospective longitudinal study to assess the effectiveness of a Lead Hazard Control (LHC) program in the City of Milwaukee from 2000 - 2004. This analysis focuses on a subset of the study population of already treated homes that contained porch and soil environmental as sampling data as well as biological monitoring blood-lead data on 71 children 6 months to 24 months old who resided in these treated homes since birth. Multivariable regression and linear structural equation modeling procedures were used to explore the mechanisms and pathways for lead intake among these urban children and the relative contribution of various lead sources to lead contamination of house dust in homes that received lead hazard control treatments approximately 3-5 years prior to the date of sampling. Results: The prevalence estimates of blood lead concentrations in children above 5 and 10µg/dL were 68% and 25%, respectively. There were disparities in the prevalence of the measured blood lead levels among certain demographic groups. In this study, the prevalence of elevated blood-lead levels (BLL =5µg/dL) was higher in boys (75.7%) than girls (58.8%) and 86.8% of the African-American children have blood lead levels above 10µg/dL. Levels of lead in floor dust were directly and indirectly associated with blood lead via other environmental exposures. Race/ethnicity and the presence of interior lead-based painted components were the strongest predictors of elevated blood-lead levels. Conclusion: This study demonstrated that lead contaminated house dust is a significant source of and contributor to lead exposure for children. Interior floor dust levels and lead levels on window sills and troughs were found to be elevated (open full item for complete abstract)

Committee: Amy Ferketich K. (Advisor); Michael Bisesi S. (Committee Member) Subjects: Environmental Science; Epidemiology; Public Health

MS, University of Cincinnati, 2004, Engineering : Mechanical Engineering

As a part of the Cincinnati Lead Program Project (CLPP), postural balance signals from postural sway motions of lead exposed children have been measured and studied in an effort to relate the motions and the blood-lead levels. We developed several signal analysis techniques including advanced time-frequency analysis such as the analytic wavelet transform and the wavelet based multi fractal analysis to the postural balance data that had been measured by the CLPP. Like many other types of biological signals, postural sway motion signals are highly transient and multi-fractal. The wavelet analysis is very well suited for analysis of such transient signals because it uses time-frequency atoms of different sizes that depend on the frequency to break down the signal. The Wavelet based Multiple-Fractal Formalism (WMFF) and the analytic wavelet transform are two techniques adopted in this research to study the postural sway motion characteristics of lead exposed children. The main goal pursued in this study is to develop quantitative metrics to relate the postural balance motion and the blood lead level of children. WMFF calculates singularity spectra of signals; therefore can be used to identify abnormalities of the signals. Theories and procedures of wavelet based multi-fractal analysis are studied. The global singularities and multifractalities are obtained for the postural sway signals of 13 low blood lead level and 10 high blood lead level children. Multi-fractal characteristics of the signals from the two groups are compared with each other by using various data representations. The result shows that the WMFF can be a very useful tool in studying the effect of lead exposure by characterizing the motions in quantitative metrics namely the maximum spectrum level and the spectrum. Various time-frequency signal analysis and representation techniques are also developed to aid qualitative analysis of the sway signals. The analytic wavelet transform technique is believed to (open full item for complete abstract)

Committee: Dr. Jay Kim (Advisor) Subjects:

PhD, University of Cincinnati, 2003, Engineering : Nuclear and Radiological Engineering

This research utilized Monte Carlo N-Particle version 4C (MCNP4C) to simulate K X-ray fluorescent (K XRF) measurements of stable lead in bone. Simulations were performed to investigate the effects that overlying tissue thickness, bone-calcium content, and shape of the calibration standard have on detector response in XRF measurements at the human tibia. Additional simulations of a knee phantom considered uncertainty associated with rotation about the patella during XRF measurements. Simulations tallied the distribution of energy deposited in a high-purity germanium detector originating from collimated 88 keV 109 Cd photons in backscatter geometry. Benchmark measurements were performed on simple and anthropometric XRF calibration phantoms of the human leg and knee developed at the University of Cincinnati with materials proven to exhibit radiological characteristics equivalent to human tissue and bone. Initial benchmark comparisons revealed that MCNP4C limits coherent scatter of photons to six inverse angstroms of momentum transfer and a Modified MCNP4C was developed to circumvent the limitation. Subsequent benchmark measurements demonstrated that Modified MCNP4C adequately models photon interactions associated with in vivo K XRF of lead in bone. Further simulations of a simple leg geometry possessing tissue thicknesses from 0 to 10 mm revealed increasing overlying tissue thickness from 5 to 10 mm reduced predicted lead concentrations an average 1.15% per 1 mm increase in tissue thickness (p<0.0001). An anthropometric leg phantom was mathematically defined in MCNP to more accurately reflect the human form. A simulated one percent increase in calcium content (by mass) of the anthropometric leg phantom's cortical bone demonstrated to significantly reduce the K XRF normalized ratio by 4.5% (p<0.0001). Comparison of the simple and anthropometric calibration phantoms also suggested that cylindrical calibration standards can underestimate lead content of a human leg up to (open full item for complete abstract)

Committee: Dr. Henry B. Spitz (Advisor) Subjects: