Publication Date

5-2022

Advisor(s) - Committee Chair

Eric Conte (Director), John Loughrin, Lawrence Hill

Degree Program

Department of Chemistry

Degree Type

Master of Science

Abstract

Steroidal hormones are naturally produced as a part of many physiological processes and are excreted in the urine and feces of animals and humans. Farm animals in concentrated animal feeding operations (CAFOs) are routinely implanted with synthetic and natural hormones to enhance growth and production, contributing significantly to environmental steroid hormone contamination. Every year around 49 tons of estrogens are generated by livestock waste in the United States alone. Due to rainfall and runoff, these steroid hormones reach the environment when animal waste is applied as manure. Studies show that estrogens and other steroidal hormones present in the surface waters disrupt the hormonal balance of many aquatic animals, hence classified as endocrine disrupting compounds (EDC). Manure borne natural estrogens estrone and 17β-estradiol are of major concern because they cause endocrine disruption in low concentrations. Male fish subjected to estrone (E1) and 17β-estradiol (E2) in very low concentrations (nanograms per liter) showed a high incidence of intersexuality and feminization. In humans, these substances cause infertility and cancer. Hence, there is a need to assess the potential risk of estrogen loading from animal waste. Complex matrices and low estrogen concentrations in the environment make the analysis challenging for analytical chemists. Our research is focused on developing a method to extract estrogens from pre and post anaerobically digested cattle waste and subsequent determination by liquid chromatography (LC) and gas chromatography (GC) with mass spectrometry detection. Since dairy cattle waste is one of the major sources of estrogen contamination, it is important to determine the concentration of hormones in fresh and stored iv samples before applying it to the farms as manure. The outcome of this study will aid in understanding the impact of anaerobic digestion on the concentrations of free estrogens and in regulating waste management practices.

Disciplines

Analytical Chemistry | Chemistry | Environmental Chemistry | Environmental Health | Pharmacology, Toxicology and Environmental Health | Physical Sciences and Mathematics | Toxicology

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