Detecting Estrogens in the Environment : Steroidal Hormones in Our Water
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Used with permission by Garland Science



Nancy Fernandes
nld25@unh.edu
Department of Biology
University of New Hampshire

Introduction


The fate of pharmaceuticals in the environment, particularly estrogens, has become a topic of concern amid a wide range of professionals and the general public. Steroidal estrogen hormones are secreted naturally by humans and animals into the environment (1). Estrogens enter both the soil and water through many routes, principally wastewater treatment effluent, treated sewage sludge, landfill leachate and animal feedlots. Hormones and antibiotics that are administered to farm animals are excreted into fields and sewage pits where they run off into surface and infiltrate into groundwater (5). Pregnant women can excrete as much as 5 mg/day of 17β-estradiol (3). Human excretion of un-metabolized synthetic estrogen into septic or wastewater systems is yet another source.
Estrogens are being detected in very low concentrations in groundwater, streams, rivers and lakes (5). Researchers use advanced analytical techniques to detect contaminants at nanograms per liter, which is about one part per trillion. To get an idea of the size of a nanogram it is the representation of one penny in ten billion dollars. This will be the standard of measurement used in this detection of estrogen in water samples.
Concentrations of estrogenic compounds in effluent of biological wastewater treatment plants range from a few nanograms per liter to several micrograms per liter. This confirms that even after treatment the effluent contains estrogenic compounds at a level that can affect some species. Estrogenic compounds are considered micro pollutants and have properties of endocrine disrupting chemicals that can disrupt the endocrine system of animals, including humans (3).
The removal of free estrogens in the environment can happen naturally (1). Natural free estrogens have low vapor pressures and thus are limited in their volatilization into the atmosphere. Bacteria in wastewater can degrade estrogenic compounds into harmless products. Absorption of estrogenic compounds into sludge from wastewater or soil is biodegraded by soil microbes; however this process is slow and inhibited by certain conditions. The soil microorganisms are inhibited by the presence of antibiotics, degrading their capacity to breakdown the estrogenic compounds. Antibiotics are commonly given to farm animals in conjunction with hormones so further research into the biodegradation pathway between estrogen and antibiotics is needed to understand this relationship. Accumulation of estrogenic compounds at deeper soil levels can be due to anaerobic conditions (3).


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Compiled by Nancy Fernandes



Effects on the Environment




1.Benotti, Mark J., Rebecca A. Trenholm, and Brett J. Vanderford. “Pharmaceuticals and Endocrine Disrupting Compounds in U.S. Drinking Water.” Environmental Science and Technology 30.42 (2008): n. pag. Ebsco Host. Web. 14 Oct. 2010.

3.Khannal, Samir Kumar, Bin Xie, and Michael L. Thompson. “Fate, Transport, and Biodegradation of Natural Estrogens in the Environment and Engineered Systems.” American Chemical Society 40.21 (2006): 6537. Ebsco Host. Web. 14 Oct. 2010. [[http://www.environmentalscience and technology.org]].

5.“Pharmaceuticals and Personal Care Products in Drinking Water and Aquatic Environments.” Environmental Fact Sheet. New Hampshire Dept. of Environmental Services, 2010. Web. 14 Oct. 2010. http://www.des.nh.gov.