Soil and Water Sciences
Winter Seminar
Dr. Thomas Borch
Departments of Chemistry & Soil and Crop Sciences
Colorado State University
- Location: 1002 CHASS Interdisciplinary Building - North
- Time: Wednesday, January 7, 2009, 12:10-1:00 pm
- Campus Map CHASS (INTN)
"Environmental Fate of Steroid Sex Hormones"
Abstract: In river systems, steroid hormones have been linked to various adverse effects on fish, including altered sex ratios, intersex fish, and diminished reproduction. Sources of steroid hormones in surface waters include discharges from wastewater treatment plants (WWTPs), runoff from agricultural feeding operations, and runoff from agricultural fields where manure and biosolids are applied as fertilizers.
The presence of steroid hormones in Colorado’s Cache la Poudre River water is being investigated by solid-phase extraction, derivatization, and gas chromatography-tandem mass spectrometry (GC-MS/MS). Multiple-reaction monitoring and isotope dilution procedures are being used for improved sensitivity and reliable compound quantification. Rainfall simulations were conducted on an agricultural field applied with municipal biosolids to investigate the potential for steroid hormone runoff and leaching. Laboratory experiments also are being conducted to investigate the potential for steroid hormone biodegradation and photodegradation under simulated natural conditions, including experiments to investigate the potential for indirect photodegradation through reactions with nitrate and humic acid (acting as photosensitizers).
Estrogens and androgens were observed at multiple sites along the river. Data from our rainfall simulation study is currently being analyzed. Biodegradation of 17ß-estradiol, testosterone and progesterone by manure-borne microorganisms in pig manure was observed and multiple degradation products were detected by liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS). Using UV-A lamps (i.e., λ > 315 nm), direct photodegradation of testosterone and progesterone was observed, and indirect photodegradation of testosterone and 17ß-estradiol was observed in the presence of 5 mg/L humic acid. Several novel photodegradation products were observed by mass spectrometry.
These findings suggest that steroid hormones are present in the Cache la Poudre River, and have the potential to undergo biodegradation and photodegradation. These findings also suggest that humic acid (acting as a photosensitizer) can facilitate the indirect photodegradation of some steroid hormones.