Estrogen Endangers Fish Populations

May 31, 2008 03:45 PM
by findingDulcinea Staff
Sewage pollutes many waterways with the female hormone. Even tiny amounts could hurt wildlife and change the sex of some fish.

30-Second Summary

Scientist Karen Kidd added synthetic estrogen to an artificial lake in Ontario, Canada, for three summers to track its impact on wildlife.

The pollution killed many fish and disrupted reproduction in others. The sperm count of male minnows fell, with some even beginning to produce eggs in their testes.

“We’ve known for some time that estrogen can adversely affect the reproductive health of fish, but ours was the first study to show the long-term impact,” Kidd said.  “What we demonstrated is that estrogen can wipe out entire populations of small fish.” 

The presence of hormonal pollutants in the country’s waterways is not new. According to Environmental Science and Technology magazine, scientists have been studying the impact of these chemicals on wildlife since the 1990s.

Intersex fish have been found in the St. Lawrence River, the Mississippi and the Great Lakes, Science Daily reports.

Wastewater, the source of the pollution, contains hormones because women excrete traces of estrogen, and many birth control drugs and household products contain compounds that chemically resemble hormones—called “hormone mimics.”

Still undetermined is what effect, if any, exposure to environmental hormones has on human health.

Scientists are studying whether hormonal pollutants “interact with the same receptor molecules inside the body that estrogen can,” Scientific American writes. If they do, the pollutants “might subtly overdose living things with excesses of hormone-like signals.”

Thankfully, the magazine reports that a number of studies into whether the pollutants contribute to breast cancer and other human health issues have provided insufficient “evidence, at least at the present, for such effects of exposure to an environmental estrogen.”

Headline Links: Hormonal pollutants decimate fish

Background: Polluted waterways create intersex fish

Analysis: Do hormonal pollutants affect human health?

Reference: How female hormones work

Related Topic: How effective is wastewater treatment?


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