UCSF National Center of Excellence in Women's Health

Program on Reproductive Health and the Environment

Links
Nicholas Kristof: It's Time to Learn from Frogs
The Colbert Report
Nicholas Kristof: Chemicals and Our Health
PRHE's comment on I Survive Steven Colbert

Endocrine Disrupting Compounds and Intersex Fish

A response to Nicholas Kristof and Stephen Colbert

Nothing like male "stunted genitals" to get Stephen Colbert's attention. Kudos to Nicholas Kristof and Stephen Colbert for recently highlighting the threat posed to America's health by endocrine disrupting compounds (EDCs) and the intersex consequences of these chemicals.

Colbert highlighted "lady pee" as a primary source of problematic EDCs in the drinking water supply. In fact, our wastewater treatment facilities filter out the vast majority of estrogens excreted by humans before the water is released to rivers, lakes and oceans (1). Furthermore, men, children and the elderly also produce and excrete estrogens, while the synthetic estrogen used in oral contraceptives contribute only 1% to the total amount of estrogens excreted by humans (2). Clearly, other sources of both natural and synthetic estrogens are contaminating our waters and contributing to intersex fish.

In terms of natural estrogens, why not blame the cow? In fact, cows, chickens, and even pigs are a grossly ignored source of estrogens, with agricultural manure contributing an estimated 90% of estrogens to the environment (3). Manure is applied directly to farmland without treatment, despite studies showing hormones from the manure can reach surface and ground water. Moreover, livestock are pumped full of hormones increasing their excretion up to six fold (4) It has been estimated that if just 1% of the estrogens excreted by livestock in the UK reached water sources, it would account for a staggering 15% of all the estrogens in water (5). Certainly, there is a significant need to study the fate and transport of livestock estrogens before dramatizing the contribution from women on the pill.

As discussed in the NY Times Opinion Column, the types and sources of EDCs in the environment are diverse, and we are exposed in more ways than just our drinking water. EDCs are all around us in plastics, household products, cosmetics, industrial chemicals, pesticides, and many are yet to be identified. Oral contraceptives in drinking water represent only a very small part of the presence of estrogens in the environment.

This is not to say we should not be concerned about EDCs, both natural and synthetic, in our drinking water. Rather, drawing such specific attention to women on the pill as a key source of the problem and ignoring other more significant sources of estrogens, like livestock and industry, is short-sighted and especially dangerous to the already contentious topic of reproductive choice and women's health.

In order to begin addressing this problem, a more concerted focus needs to be placed on solutions and reforming chemical policy. It's true that the pollution of waterways by these chemicals falls under the jurisdiction of the EPA to regulate. It is also unfortunately true that the chemical policy structure in the United States puts the burden of proving a chemical's harm (or safety) on the government and NOT the companies that manufacture them. It's great to see such an important issue being brought to light and we hope this can begin the process of discourse about how to better protect our health and the environment.

References

1. de Mes T, et al. Occurrence and fate of estrone, 17beta-estradiol and 17alpha-ethynylestradiol in Sewage Treatment Plants for domestic wastewater. Reviews in Environmental Science and Biotechnology (2000) 4:275-311.

2. Central Bureau of Statistics (2002) Statline, http://www.cbs.nl/

3. Maier RM, et al. Terrestrial Environment. In Environmental Microbiology; Academic Press: 2000; pp 61-80.

4. Callantine MR, et al. Fecal elimination of estrogens by cattle treated with diethylstilbestrol and hexestrol. Am J Vet Res. (1961) 22:462-465.

5. Johnson AC, et al. The potential steroid hormone contribution of farm animals to freshwaters, the United Kingdom as a case study. Science of the Total Environment (2006) 362:166-178.

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