Keith Grasman (Advisor)
Master of Science (MS)
This thesis contains two separate and distinct research projects with a common overall theme - the study of immunotoxicity associated with the developmental exposure of young birds to halogenated chemicals posing environmental concern. These chemicals share many chemical characteristics, including environmental ubiquity and longevity, one has been studied extensively since the 1970s, and one is a relatively new environmental contaminant with few studies pertaining to toxicological affects on humans or wildlife. Specific summaries of each study begin each project chapter. The first study was entitled Developmental and Immunological Effects of a Commercial Mixture of PBDE Flame Retardants in Chicken Embryos. The primary objective of this study was to determine if chicken embryos exposed in ovo to a commercial mixture of polybrominated diphenyl ethers (PBDEs), a halogenated flame retardant sharing many characteristics with PCBs and dioxins, presented indication of toxicity by way of increased mortality, developmental abnormalities, or immunotoxicity. Chicken (Gallus gallus) embryos were exposed to a commercial PBDE mixture in ovo via air cell injection at environmentally relevant concentrations. This study resulted in minimal impacts by PBDEs with respect to mortality and immunotoxicity at the doses tested, but interesting, however non-significant results with respect to deformities. The second study, entitled Immunotoxic Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the Wood Duck (Aix sponsa): A Sensitive Indicator Species?, was conducted in cooperation with the US Fish and Wildlife Service in Raleigh, NC. The objective of this research was to determine if wood ducks exposed in ovo to environmentally relevant concentrations of TCDD expressed signs of immunotoxicity. Previous research has shown that wood ducks may be extremely sensitive to low dioxin levels. Accounting for high sensitivity to dioxin-like chemicals and certain life history and behavioral patterns associated with wood ducks, results of previous research has suggested that wood ducks may be an ideal indicator species for environmental contamination and remediation. The study herein described effects by wood duck embryos exposed to environmentally relevant concentrations of TCDD in ovo via yolk injection. While the present study exhibited high background mortality, no statistically significant toxicity was revealed in terms of increased dose-related mortality or immunotoxicity characteristic of dioxin toxicity.
Department or Program
Department of Biological Sciences
Year Degree Awarded
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