| The aim of this dissertation was to determine the concentrations of emerging brominated flame retardants (BFRs) compounds such as polybrominated bisphenyl ethers (PBDEs), hexabromocyclohexane (HBCDs), and tetrabromobisphenol A (TBBPA), along with legacy organochlorine contaminants such as polychlorinated biphenyls (PCBs), in human and marine wildlife samples from the U.S. to evaluate bioaccumulation, food chain transfer, and exposure levels of these compounds. PBDEs were also measured in the indoor environment including samples of house dust and indoor air to understand the major pathways of human exposure.;The major findings of this dissertation were that PBDE concentrations both in adipose tissue and breast milk samples from the U.S. population are 10 to 100-times greater than the concentrations reported for the rest of the world. HBCDs and TBBPA concentrations in the U.S. population were lower than the concentrations found in Europe. These exposure differences between the U.S. population and the rest of the world were explained by the usage pattern and market demand for BFRs. This was the first report to document the occurrence of HBCDs and TBBPA in humans and marine top predators from the U.S. Concentrations of PBDEs in human adipose tissues from the U.S. are similar to, or else greater than, the concentrations of PCBs. Human exposure to PBDEs, unlike to PCBs, occurs in the indoor environment. In contrast, major source of PCB exposures in humans is through the consumption of contaminated seafood or meat products. In this dissertation, it was determined that PBDE exposures in infants less than 1 year old are higher than the exposures in adults. This was explained by considerable PBDE contaminations of human breast milk from the U.S. For adults, the major sources of PBDE exposure were found to be ingestion and dermal absorption of house dust and inhalation of indoor air. Since marine ecosystems are the ultimate sink for many persistent and lipophilic contaminants, further studies are needed to evaluate the future trends and risks posed by these compounds to humans and marine organisms. |
