ISEE-268 Introduction: Polybrominated diphenyl ethers (PBDEs) are fire retardants commonly found in consumer products such as foam cushions, carpets and computers. Up to 30% of some products, these compounds are not covalently bound to the plastic and can escape into the indoor environment. PBDEs are reproductive and developmental neuro-behavioural toxicants in laboratory animals. Outstanding research questions include key routes of human exposure and impacts on human health. The limited data on US residents suggest levels one to two orders of magnitude higher than elsewhere. The goal of our current research is to investigate concentrations in women of child-bearing age from the greater Boston area and to examine potential routes of exposure, particularly the roles of diet and the indoor environment. Methods: Breast milk has higher lipid levels than blood, providing a sensitive, relatively noninvasive method for estimating maternal body burdens of lipophilic compounds. We collected breast milk from first-time mothers, 2-8 weeks after birth. We restricted participation to English or Spanish-speaking residents of the greater Boston area for at least three years. Such restrictions help standardize results across studies. After education regarding the benefits of breast feeding, we enrolled women from three different clinics/maternity centers. We collected questionnaire data on personal characteristics, diet, furniture, use of computers and occupation. We sampled house dust from a subset of participants using a portable hand-held vacuum. Milk and dust samples were analyzed using GC/MS. Milk concentrations are provided on a lipid basis. Results: We report here results from the first 22 milk samples. Concentrations were log-normally distributed, ranging from 10 to 110 ng/g with a median of 27 ng/g. PBDE 47 was the dominant congener in almost all samples (median= 14 ng/g). PBDE 153 was the second highest congener is most samples (median = 3 ng/g), but it dominated in two samples, possibly indicating unusual exposures. PBDE 209 was above detection limits in 4 samples. Congeners 47, 66, 85, 99, 100, 138 and 154 were highly correlated (r>0.70). We will report results from the other half of the participants and preliminary comparisons with questionnaire data and dust samples at the meeting. Conclusion: This research is the first systematic examination of PBDEs in humans in the Northeast USA and one of the only US studies with standard participation restrictions and non-convenience sampling. Our results are qualitatively similar to other published US studies: highly skewed distribution, dominance by PBDE 47. Our median concentration of total PBDEs (27 ng/g) is comparable to a study in Texas (34 ng/g); concentrations in the two groups were not significantly different (Wilcoxon test, p=0.21).

ISEE-438 Abstract: The rapid increase in the body burden of polybrominated diphenyl ethers (PBDEs) worldwide, as well as their structural and toxicological similarity to PCBs, has raised concerns about the potential for human health impacts. Recent study results from California, Texas, and Indiana indicate that body burden levels in the United States are 1-2 orders of magnitude higher than similarly measured body burdens in Europe and Asia. PBDEs are more widely used in the United States than other countries, but it is not known whether diet, consumer habits (e.g., computer usage), or occupational or environmental pathways are primary routes of exposure. The Project is measuring the concentration of PBDEs in the breast milk of 50 first time mothers from two different health centers. Each participant is being interviewed with regard to her dietary, consumer, occupational, and environmental habits which may be related to PBDE exposure. Breast milk samples are being collected within the first two post-natal months. We will analyze the questionnaire data along with results of breast milk analysis for correlation between various exposure parameters and body burden. The patient populations at the two health centers are quite different with regard to socio-economic and ethnic background. We selected these two distinct centers so that potential differences in exposure patterns and body burden may be identified. This study design may also help determine if there is a highly exposed population due to a particular exposure pathway. In addition to breast milk analysis, this study includes a home dust sampling protocol. This protocol is being implemented in the homes of a portion of the 50 participants. Concentrations of PBDEs in house dust and breast milk will be examined and compared. The results of this study will be used to determine the relative importance of in-home consumer habits as compared to occupational or environmental exposure.