How Estrogens Persist in Dairy Wastewater

And You Thought Estrogens and Menopause was BAD…

A recent report has shown that wastewater from large dairy farms contains significant concentrations of estrogenic hormones. Now that’s bad news as these hormones can persist forĀ  months and years and in the absence of oxygen, the estrogens rapidly convert from one form to another. This effectively stalls their biodegradation and complicates efforts to detect them.

The study is from the journal Environmental Science & Technology was led by scientists at the Illinois Sustainable Technology Center. They are reportedly the first to document the unusual behavior of estrogens in wastewater lagoons.

Just as new mothers undergo hormonal changes that enable them to breastfeed, confined animal feeding operation, articles.waterdesalinationplants.comlactating cows generate estrogenic hormones that are excreted in urine and feces, said ISTC senior research scientist Wei Zheng, who led the study. In large “confined animal feeding operations” (CAFOs) the hormones end up in wastewater. Farmers often store the wastewater in lagoons and may use it to fertilize crops.

Federal laws regulate the flow of nutrients such as nitrogen and phosphorus from CAFOs to prevent excess nutrients from polluting rivers, streams, lakes or groundwater.

It appears that environmental officials have assumed that such regulations also protect groundwater and surface waters from contamination with animal hormones and veterinary pharmaceuticals. This has not been proven.

Did You Know?

Hormone concentrations in livestock wastes are 100 to 1,000 times higher than those emitted from human sewage treatment plants, and large dairy farms are a primary source of estrogens in the environment, according to Zheng. Recent studies have detected estrogenic hormones in soil and surrounding watersheds after dairy wastewater was sprayed on the land as fertilizer.

“These estrogens are present at levels that can affect the (reproductive functions of) aquatic animals,” Zheng said. Even low levels of estrogens can “feminize” animals that spend their lives in the water, causing male fish, for example, to have low sperm counts or to develop female characteristics (such as producing eggs), which would be a definite problem in them being able to reproduce!

Hormones that end up in surface or groundwater could contaminate sources of drinking water for humans, Zheng said. “The estrogens may also be taken up by plants — a potential new route into the food chain,” he said.

When exposed to the air, estrogenic hormones in animal waste tend to break down into harmless byproducts. But the hormones persist in anoxic conditions, meaning where there is a lack of oxygen.

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