The Fate of Hormones in the Aquatic
Environment
Figure 1. Examples of
hormones present in the aquatic environment effluent.
Starting in the early 1990s, researchers began reporting feminization
of male fish (e.g., the presence of egg proteins in their
blood).
In rivers that received significant inputs of municipal wastewater
effluent, the feminization of male fish was found to be attributable to
the presence of steroid hormones, such as 17beta-estradiol, ethinyl
estradiol and estrone (Figure 1). Over the past decade, our
research group has developed analytical methods for quantifying the
extremely low concentrations of steroid hormones present in the aquatic
environment (e.g., certain species of fish can be feminized by exposure
to steroid hormones at concentrations as low as 1 ng/L). We
also
have studied the fate and transport of these compounds and more
recently have begun to study sources of steroid hormones unrelated to
municipal wastewater.
As we learned in the initial phase of our research (Huang et al. 2001),
the concentrations of steroid hormones in municipal wastewater effluent
usually are high enough to induce feminization of fish. In
some
cases, the concentrations also are high enough to interfere with
chemical communication among fish, which is crucial to successful
reproduction (Kolodziej et al. 2003). While it may be
possible to
reduce the concentrations of steroid hormones to levels that do not
pose a risk by applying advanced treatment methods, such as reverse
osmosis, most utilities are reluctant to invest in such expensive
treatment systems. Engineered treatment wetlands provide a
potentially cost-effective approach for reducing the concentrations of
steroid hormones. Doctoral research conducted by James Gray
(Gray
and Sedlak 2005) demonstrated the partial removal of steroid hormones
in an engineered wetland located near Los Angeles (Figure 2).
However, the removal was incomplete and additional research is needed
to quantify the roles of sorption, biotransformation and photolysis in
the removal process. In the next few years we hope to pursue
this topic further at a treatment wetland that we helped build in
Discovery Bay, CA.
Figure 2. Engineered
Treatment Wetlands.
More
recently, we have
begun to turn our attention to sources of steroid hormones unrelated to
wastewater effluent. We have
found elevated concentrations of steroid hormones in watersheds where
grazing cattle have access to streams and are currently studying the
release of steroids form animal feeding operations and pastures through
a grant
funded by the USEPA being conducted in collaboration with Thomas Harter (UC Davis) and Ed Kolodziej (University of Nevada). We also are studying
the potential impacts of steroid hormones and other
endocrine-disrupting compounds in California's Central Valley as part
of a CALFED
project being conducted in
collaboration with Professor Daniel
Schlenk
(UC Riverside).
For more information see:
Kolodziej E.P. and Sedlak D.L. (2007)
Rangeland grazing as a source of steroid hormones to surface waters.
Environ. Sci. Technol. 41: 3514-3520.
Gray J.L. and Sedlak D.L. (2005) The fate of
estrogenic hormones in an engineered treatment wetland with dense
macrophytes. Water Environ. Res.,77, 24-31.
Huang, C.H. and Sedlak, D.L. (2001) Analysis
of estrogenic hormones in
municipal wastewater effluent and surface water using ELISA and
GC/MS/MS. Environmental Toxicology and Chemistry, 20, 133-139.
Kolodziej E.P., Harter T. and Sedlak D.L.
(2004)
Dairy wastewater, aquaculture and spawning fish as sources of steroid
hormones in the aquatic environment. Environ. Sci. Technol., 38,
6377-6384.
Kolodziej E.P.,De Gray J.L. and Sedlak D.L.
(2003)
Quantification of steroid hormones with pheromonal properties in
municipal wastewater effluent. Environmental Toxicology and Chemistry,
22, 2622-2629.
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The Fate of Hormones in the Aquatic Environment
Use of Iron to Control Methlmercury Formation in Wetland Sediments
Oxidation of Contaminants by Iron
Nanoparticles in the Presence of Oxygen
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