David Kim - Doctoral Dissertation Final Defense

Abstract:
Dermal exposures to Jet-Propulsion Fuel 8 (JP-8) are prevalent in the United States Air Force. Although a large amount of exposure data was generated from previous occupational studies, dermal exposures to JP-8 were poorly characterized and quantitative estimates of the contribution of dermal exposure to the internal dose of JP-8 were unavailable. To fill this data and knowledge gap, a controlled dermal exposure study was designed. The data generated from this study was used to quantify the toxicokinetic behavior of naphthalene, 1-methyl naphthalene, 2-methyl naphthalene, decane, undecane, and dodecane. Further, a toxicokinetic model was constructed; this model provided the basis for the development of a physiologically-based toxicokinetic (PBTK) model of dermal and inhalation exposure to JP-8. The PBTK model was used to quantify the contribution of dermal exposure to the internal dose of naphthalene. Three distinct phases of research are presented here: design of a controlled dermal exposure study; development of a dermatotoxicokinetic model for predicting exposures to JP-8; construction of a PBTK model that includes the dermal and inhalation routes of exposure to JP-8. The two most significant contributions to the scientific understanding of JP-8 exposures were (1) improved characterization of dermal exposures, and (2) quantitation of the toxicokinetic behavior of aromatic and aliphatic hydrocarbons. This investigation has integrated environmental exposure and biological monitoring data into a toxicokinetic model. The integration of data from different studies has improved our understanding of dosimetry and exposures to JP-8. Overall, this research has presented a new direction for toxicokinetic modeling human exposures to complex chemical mixtures. This modeling strategy may be used to better assess the risks associated with JP-8 exposures in human populations.

Committee Members:

Dr. Leena Nylander-French
Dr. Louise Ball
Dr. Stephen Rappaport
Dr. Dana Loomis
Dr. Melvin Andersen

For further information please contact Rebecca Riggsbee Lloyd by email at Rebecca_Lloyd@unc.edu