Estrogen, antibiotics persisted in dairy farm waste after advanced treatment, study finds

http://www.eurekalert.org/pub_releases/2016-02/uab-eap021016.php

Public Release: 10-Feb-2016
Estrogen, antibiotics persisted in dairy farm waste after advanced treatment, study finds
The chemicals' endurance may pose a threat to the environment and human health
University at Buffalo

When University at Buffalo chemists began studying waste disposal at a dairy farm in New York State, they thought that the farm's advanced system for processing manure would help remove estrogens and antibiotics from the excrement.

Instead, the scientists found that the chemicals largely persisted in the treated materials, which are typically reused as fertilizer and animal bedding on the farm.

The waste management process -- an advanced anaerobic digestion system -- also converted a less harmful form of estrogen in the manure into a form that may pose a greater ecological threat.

The study underscores how far waste treatment techniques have fallen behind the times.

Hormones and antibiotics, if not removed from waste, can migrate into the environment and threaten wildlife. [They also threaten human health.] Estrogens, for example, can enter rivers and lakes, causing male fish to develop female traits -- a phenomenon that can harm reproduction. [Human sperm counts around the world have been decreasing for years.] Rogue antibiotics pose a different kind of challenge, encouraging the spread of antibiotic resistance, in which disease-causing bacteria stop responding to drugs.

Even waste treatment systems that are considered to be state-of-the-art often fail to account for chemicals used routinely in modern society, says University at Buffalo researcher Diana Aga, who led the new study. She is a professor of chemistry in the UB College of Arts and Sciences and a member of UB RENEW (Research and Education in eNergy, Environment and Water), an institute that addresses complex environmental issues.

"The chemicals we are studying are not exotic," Aga says. "Antibiotics are used to treat sick animals, and the cows on a dairy farm are females, so they produce a lot of estrogens.

"One of the messages of our work is that even anaerobic digestion, an advanced treatment, doesn't totally remove these chemicals which may pose a danger to the environment. We need to start looking closely at additional treatment techniques to identify better practices."

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