Study examines link between PBB exposure and menstrual cycle function

Researchers at the Emory Rollins School of Public Health recently published a study in Epidemiology that looked at the long-term impact of polybrominated biphenyl (PBB) exposure on menstrual function in a group of women exposed to the chemical 40 years before. Penelope Howards, PhD, was first author on the paper. 

The study specifically looked at a group of women who may have been exposed to the chemical through beef or dairy consumption after livestock feed was accidentally contaminated during an industrial accident in 1973-1974 in Michigan. Researchers found that women exposed to high levels of PBB had different hormone levels across their menstrual cycles compared with women with low exposure. The shift in hormone levels in women exposed to high levels of PBB was consistent with what would be expected of women who were exposed to an exogenous estrogen. 

While the specific flame retardant examined in this study is no longer produced in the U.S., other similar brominated flame retardants are still being produced. Findings from this work complement previous findings that PBB is associated with epigenetic markers that are regulated by estrogen (heightened breast cancer risk, spontaneous abortion, and earlier menarche).

The researchers note that the findings of this study should be interpreted with caution due to the small size of the study. However, these results suggest the need for additional research into the potential effects of exposure to similar compounds on hormone levels given that hormone levels are associated with a number of reproductive and women’s health outcomes.