Polybrominated Biphenyl Exposure and Reproductive Hormone LevelsEPA Grant Number: F07D30740
Title: Polybrominated Biphenyl Exposure and Reproductive Hormone Levels
Investigators: Taylor, Kira Creswell
Institution: Emory University
EPA Project Officer: Manty, Dale
Project Period: January 1, 2007 through January 1, 2010
RFA: STAR Graduate Fellowships (2007) RFA Text | Recipients Lists
Research Category: Endocrine Disruptors , Academic Fellowships , Fellowship - Epidemiology
The question of whether "endocrine disrupters" such as polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), and other halogenated hydrocarbons, may affect the reproductive health of humans, has gained a great deal of attention in both the popular press and scientific journals. There is evidence that this family of structurally similar halogenated organics causes endocrine disruption in humans and wildlife. These chemicals are widespread in occurrence, resistant to degradation, and accumulate in fatty tissue. The mechanism by which these chemicals cause endocrine disruption is not well-established, although there is some evidence that they may mimic estrogen, causing either estrogenic or anti-estrogenic effects. Therefore, it is possible that these chemicals exert their effects either directly or indirectly by altering levels of estrogen and other reproductive hormones. The purpose of this project is to quantify the association between serum PBB concentrations and urinary levels of estrogen and progesterone metabolites, and follicle stimulating hormone (FSH), across the menstrual cycle.
In 1976-77, the Michigan Department of Community Health organized nearly 4000 individuals potentially exposed to PBB into a registry and obtained baseline health information as well as serum samples. Women who were between the ages of 18 and 46, not using oral contraceptives, and not pregnant or lactating were eligible for the present study. The women collected first morning daily urine samples and completed daily diaries with information on menstrual bleeding and covariates. We will model the effect of serum PBB levels on cycle day 3 (“basal”) levels of estrogen and progesterone metabolites, and FSH. We will also examine PBB’s effects on these hormone levels in a 17-day window surrounding ovulation.
Some investigators have argued that rising incidence of breast, prostate and testicular cancer, cryptorchidism, ectopic pregnancies, and early endometriosis may be related to the introduction of endocrine disruptors—both known and unknown—into the general environment. By determining whether there is an effect of PBBs on estrogen and progesterone metabolites and FSH, we will gain knowledge into how endocrine disruptors modify menstrual cycle characteristics, and perhaps fertility and the reproductive lifespan. The results of this study could have implications for policy and environmental regulations to improve public health, by providing crucial evidence needed to demonstrate the mechanism by which endocrine disruptors affect these outcomes which threaten both the survival and well-being of animals and humans.