Date of Degree
PhD (Doctor of Philosophy)
Civil and Environmental Engineering
Keri C. Hornbuckle
In this dissertation I compare concentrations of polychlorinated biphenyls (PCBs) and hydroxylated PCBs (OH-PCB) in serum of children and their mothers from urban and rural U.S. communities, determine the variability of these concentrations from year to year, and report the detection of OH-PCBs in sediment from a Lake Michigan waterway and original commercial Aroclors. I developed extraction and analytical methods for the analysis of PCBs and OH-PCBs in 377 human serum samples and 20 sediment samples. I also developed a quality assurance protocol and analyzed more than 300 quality control samples for the purpose of generating an accurate, reproducible, representative, and precise data set.
I found that concentrations of PCBs were much higher in mothers than their children, and concentrations of OH-PCBs were slightly higher in mothers than their children. Children were enriched in lower molecular weight PCBs indicating the importance of environmental exposure to their blood concentrations. I also determined that concentrations were similar between the urban and rural residents. These concentrations were similar to concentrations reported in the U.S. general population and other populations without high dietary PCB intake. In East Chicago and Columbus Junction participants, concentrations of OH-PCBs demonstrated a strong positive relationship with PCBs. Variability in PCB and OH-PCB concentration from the first year to the second in most participants exceeded the estimated analytical variability. Observed variability could be due to exposure differences, physiological changes such as metabolism and weight, or a combination.
I also discovered the presence of OH-PCBs in the sediment from the Indiana Harbor and Ship Canal (IHSC), a Lake Michigan Waterway. In a first-approach, evidence from analysis of the correlations between OH-PCBs and PCBs in the same sediment is consistent with limited biotic activity. I also report OH-PCBs as contaminants in original commercial Aroclors, and OH-PCB profile similarities between the Aroclors and sediment suggest that Aroclors are the major source of OH-PCB contamination in IHSC. This is a significant finding because OH-PCB contamination of sediment exists anywhere that PCB contamination from Aroclors is present.
children, metabolism, mothers, OH-PCBs, PCBs, sediment
xiv, 126 pages
Includes bibliographical references (pages 119-126).
Copyright 2013 Rachel Frances Marek