O-25: The Effect of Environmental Contaminants Endocrine-Disrupting PBBs and PBDEs on Reproduction and Fertility Outcomes

Background: Polybrominated Biphenyls (PBBs) and Polybrominated Diphenyl Ethers (PBDEs) are semi-permanent Halogenated compounds that are mainly used in flame retardant. These contaminants as endocrinedisrupting associated with dysfunction of immune, endocrine and nervous systems. Influence various physiological processes such as menarche, birth weight, fetus growth and development, head circumference and gestational age during prenatal and postnatal periods. Materials and Methods: In a cohort study including 1111 birth and 560 women, the association between PBBs with gestational age and birth weight was assessed. In this study participants were classified into 3 groups: under 10 (64), 11-16 and 17-42 years old. Measured PBBs levels were in the range of 0 to 1490 ppb and the mean of each group was 2, 3 and 2 respectively. Serum levels of PBBs were much higher in the younger age exposure. The result of this study show that mothers who have been exposed to these pollutants in younger ages (under 10 years old and before of puberty) were at higher risk for increasing birth weight; 16 gram more birth weight for every 10 ppb increasing in serum level of PBBs. This study shows no effect on gestational age. Results: Studies shown the Half-life of PBBs is 10.8 years in humans. These contaminants are considered disrupting of immune, endocrine and nervous systems. The mechanism of these disrupting is binding to acyl hydrocarbon receptor (ah), cytochrome p450 gene expression and alternation the genes have key role in growth and development. Some of them act by interfering with the estrogen hormone. Conclusion: In a study including 20 pairs of mother and child have seen that higher levels of PBDEs in breast milk has relationship with under mean birth weight (<3.05 Kg).