Understanding environmental influences on bioaccumulation of contaminants of emerging concern among fish species.

By 2050, ~ 70% of the global population will live in urban areas. Concurrently, chemical pollution presents risks to humans and the environment around the world, and chemical production exceeds interventions in many regions. Pharmaceuticals and per-and polyfluoroalkyl substances (PFAS) are two groups of chemicals receiving attention due to their presence in the environment and potential to negatively affect human and environmental health. These chemicals have physicochemical properties which make traditional tools for assessing bioaccumulation, like log KOW, difficult, as both groups can be ionized at environmentally relevant pHs. Therefore, I aim to better understand how the environment influences bioaccumulation of pharmaceuticals and PFAS among fish species. First, I conducted a field study examining uptake of pharmaceuticals by rainbow trout in an urban river, influenced by snowmelt, during summer and fall seasons. I found pharmaceutical concentrations in fish corresponded to levels in surface water, but uptake kinetics for study pharmaceuticals did not differ among sites or seasons. These observations suggest inhalational exposure from water governed accumulation and uptake rate is independent of surface water concentrations. I then tested a human to fish biological read-across hypothesis for pharmaceutical disposition by examining tissue-specific accumulation in three understudied fish species, from an urban river. Pharmaceutical concentrations paralleled human disposition patterns, but differential accumulation was observed. This research supports prioritizing pharmaceuticals for future comparative bioaccumulation, biotransformation, and toxicology studies among potentially susceptible fish species. Next, I examined uptake of a mixture of PFAS by Pimephales promelas over 7 days, under laboratory conditions. I then identified significant relationships between different physicochemical properties and bioaccumulation, including the apparent volume of distribution, which shows promise for assessing PFAS bioaccumulation. Finally, I examined influences of pH and salinity on PFAS uptake and elimination by Pimephales promelas in 21-d bioaccumulation experiments, under laboratory conditions. I observed no influence of pH nor salinity on bioaccumulation, rapid uptake, and limited elimination of PFAS, highlighting needs to consider elimination in bioaccumulation studies, especially among fish species, to develop a comparative understanding of PFAS bioaccumulation. This dissertation integrated diverse approaches for assessing bioaccumulation of contaminants of emerging concern among fish species.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Doctoral

Grantor

Baylor University.

Year dc:date.issued

2024

Author dc:creator

• Sims, Jaylen L., 1995-

Advisor dc:contributor.advisor

• Brooks, Bryan W.

• Bioaccumulation.
• Environmental toxicology.
• Ecotoxicology.
• Analytical chemistry.
• Environmental chemistry.
• Pharmaceuticals.
• Per- and polyfluoroalkyl substances (PFAS)

Statement dc:rights

• Baylor University works are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. Contact libraryquestions@baylor.edu for inquiries about permission.

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/2104/13580

OAI identifier oai:identifier

oai:baylor-ir.tdl.org:2104/13580