Semester of Graduation

Spring 2024


Master of Science (MS)


Environmental Science

Document Type



Chemicals are often released via anthropogenic means both intentionally and unintentionally into aquatic environments. The chemical fate of these compounds can vary greatly depending on numerous factors that can include but are not limited to salinity, pH, dissolved oxygen, and exposure to ultraviolet radiation. The goal of this study was to investigate the effect of UV radiation on the level of toxicity of different chemicals over time. Chemicals were selected based on previous studies of the toxicity of both parent and metabolites formed as a result of photolysis. Anthracene, phenanthrene, anthraquinone, dicloran, chlorothalonil, hydroxy chlorothalonil, benzobicyclon hydrolysate, and sertraline were selected as representative of three distinct chemical categories: polyaromatic hydrocarbons, pesticides, and pharmaceuticals. Samples of each chemical were irradiated and measured at 5-hour intervals for up to 25 hours. Treated samples were assessed using in-vitro bioassays to identify changes in biological response as a result of UV irradiation over time. In-vitro bioassays are a method of measurement designed to assess the potency of a chemical based on its effect on ability to elicit a response within living cells, without the need to use whole organisms. Commercially available, all-inclusive cell-based luciferase reporter assay kits were used to measure the activity of four target nuclear receptors: the Zebrafish Peroxisome Proliferator-Activated Receptor gamma, the Zebrafish Estrogen Receptor Alpha, the Zebrafish Aryl Hydrocarbon Receptor, and the Zebrafish Retinoic Acid Receptor alpha isoform A. Changes in receptor activity varied between chemicals, with some observable changes measured with increasing irradiation exposure time. Further assessment, to increase replicate numbers, is required to confirm any observed changes. This assessment was used as an initial screening to identify potential changes in toxicity and highlight promising directions for future study.



Committee Chair

Armbrust, Kevin L.

Available for download on Saturday, April 05, 2025