Birth control hormones in water: separating myth from fact.

The past several years have seen a steady drumbeat of news reports, blog posts, and scientific studies which have raised concerns about the presence of estrogenic compounds (natural estrogens and synthetic chemicals that mimic natural estrogen) in waterways and drinking water, and potential harm to human health or aquatic life [1–3]. Frequently, one particular synthetic estrogen has been singled out for purportedly detrimental effects on the environment: ethynyl-estradiol, or EE2, a synthetic estrogen used in birth control pills, patches, rings, and injectables. Journalists from along the political spectrum and anti-contraception advocates alike have seized on the idea of the-Pill-as-environmental-pollutant, and it has been difficult to separate environmental health concern from sensational coverage or politically motivated rhetoric. At the same time, anecdotal evidence suggests environmental footprint or “greenness” is increasingly one of the factors that many women consider in choosing among birth control methods, along with effectiveness, safety, convenience, cost, and acceptability [4–6]. This raises the possibility that reports about the environmental impact of hormonal contraception could influence a woman's choice of this method, and underscores the need to understand the current science and provide women with unbiased information that allows them to make informed choices. The effect of estrogenic compounds in the water supply from industry, agriculture, and other sources raises concerns about human health and deserves scrutiny. Estrogenic compounds are part of a larger category of chemicals known as endocrine-disruptors (EDCs), chemicals that can alter the hormonal and homeostatic systems enabling an organism—like a human being or other animal—to communicate with and respond to its environment [7]. Given the demonstrated effects of EDCs on human reproductive health, it is important to examine the role played by EE2 in contributing to the presence of estrogenic compounds in our water [7]. The good news is this: contrary to what has been stated or implied by media reports and anti-contraception advocates, synthetic estrogen from birth control pills is not the sole or primary source of endocrine-disrupting chemicals in water [8]. New findings from researchers at the University of California San Francisco (UCSF) Program on Reproductive Health and the Environment (PRHE) help explain why—