[Pharmwaste] Bacteria in sewage can change estrogens' chemical makeup

[Tenace, Laurie]

http://www.environmentalhealthnews.org/ehs/newscience/bacteria-in-sewage-can-
change-estrogens

Bacteria in sewage can change estrogens' chemical makeup. 
Jun 05, 2009 


Gomes, RL, MD Scrimshaw and JN Lester. 2009. Fate of conjugated natural and
synthetic steroid estrogens in crude sewage and activated sewage sludge batch
studies. Environmental Science & Technology doi: 10.1021/es801952h.

Synopsis by Paul Eubig, DVM 


Bacteria in sewage can alter the chemical makeup of natural and synthetic
estrogens that are found in the wastewater. 


Bacteria in sewage can chemically transform estrogenic compounds, converting
them to back to their original chemical form as the sewage travels toward
treatment plants after the compounds have been excreted by people. This
conversion makes the bacteria more amenable to being filtered out of the
water by  treatment.

The findings open the door to exploring new ways in which the estrogens that
are more resistant to bacterial modification could be changed at the sewage
treatment plant to make them easier to remove from the water.

Not all of the estrogens, however, can be changed. Which are depends on time,
temperature and whether the estrogens are synthetic or natural, the
researchers report.

Recent research has shown that human-related estrogens are found in lakes,
rivers and other waterways, likely arriving there from water that has passed
through the sewage treatment process. The hormones can affect the health and
reproduction of  fish and other creatures that call the water home. Fish with
both male and female gonads, as well as feminized male fish, have been
reported in species living downstream from treatment plant outflows. Some
studies have linked these abnormalities to the estrogen hormones found in
sewage.

The estrogens are mainly excreted from people through their urine. They can
be natural estrogens or synthetic ones, such as those found in birth control
pills or hormone replacement therapy.

Before estrogens can leave the human body, they are chemically transformed,
or metabolized.  The body tacks on a molecule that allows the hormones to
pass into the urine rather than remain in fat or blood.

Researchers in England examined what happens to these estrogens in the
wastewater after they enter sewage treatment plants. In a series of
experiments, they better defined how bacteria further chemically modify the
estrogens in the sewage.

They found that several things happen. Certain types of metabolized estrogens
are converted back to their original form by the bacteria in the sewage.
Other types of metabolized estrogens are more resistant to modification and
remain unchanged or are altered in different ways.

This is not as worrisome as it sounds. The bacteria in our own digestive
systems perform the same kinds of chemical modifications on the foods we eat
and the drugs we take. It is likely that the bacteria in our digestive
systems are the same ones acting on the estrogens in wastewater, the authors
speculate.


Laurie Tenace
Environmental Specialist
Waste Reduction Section
Florida Department of Environmental Protection
2600 Blair Stone Rd., MS 4555
Tallahassee FL 32399-2400
P: 850.245.8759
F: 850.245.8811
Laurie.Tenace at dep.state.fl.us 

Mercury: http://www.dep.state.fl.us/waste/categories/mercury/default.htm 

Unwanted Medicine:
http://www.dep.state.fl.us/waste/categories/medications/default.htm



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