| Summary: | Endocrine disrupting compounds (EDCs) are chemicals that can block or mimic natural hormones in the endocrine system. EDCs enter the environment through the disposal of unwanted drugs through garbage and after their intended use, through excretion. EDCs are resistant to biodegradation and are highly water soluble, leading to limited removal by wastewater treatment plants. As a result, the compounds can easily enter the aquatic environment biologically active and risk exposure to aquatic organisms affecting their behavior, anatomy, and physiology. There is, however, not sufficient research on the effects of EDCs on aquatic vertebrates to have a full understanding of the damage done to these organisms by EDC pollution. Exposing fathead minnows at environmentally relevant concentrations allows for an accurate representation of how EDCs affect and accumulate in aquatic vertebrates. Mimicking singular exposures for seven EDCs at seven days will represent how EDC pollution affects aquatic wildlife during acute exposure events. After exposure, the entire organism will be analyzed quantitatively by liquid chromatography mass spectrometry (LC-MS) and qualitatively by matrix assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI). Imaging allows for the precise determination of which tissues and organs the drugs are accumulating. The EDCs being studied include four beta-blockers two selective serotonin reuptake inhibitors (SSRIs), and a serotonin norepinephrine reuptake inhibitor (SNRI). Results show after seven days of exposure there is accumulation of EDCs in the fathead minnows. MALDI-MSI results have shown the specificity of accumulation of the beta-blockers and SSRI compounds in regions of the minnow. Propranolol accumulated within the abdominal organs and muscles. Atenolol, citalopram, and paroxetine accumulated within the brain of the minnows. These regions were dissected from the minnow and analyzed by LC-MS for quantitative analysis. Propranolol, citalopram, and paroxetine were detected and quantified at all three exposure concentrations, while atenolol was only detected at the two highest exposure concentrations.
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