Understanding spatial and temporal aquatic exposure and hazards of contaminants of emerging concern.

Contaminants of emerging concern (CEC) encompass both natural and anthropogenic compounds in the aquatic environment and are of concern to both human and aquatic species exposure. However, we do not have a robust understanding of spatial and temporal exposure to a diverse range of CECs and how these dynamics influence water quality hazards. Here I examine the occurrence of multiple of these contaminants including perand polyfluoroalkyl substances (PFASs), persistent organic pollutants (POPs), and harmful algal bloom (HAB) toxins. First, I performed a critical review of existing literature to understand the global occurrence of PFASs within surface and groundwaters followed by a probabilistic hazard assessment utilizing environmental exposure distributions compared to various regulatory levels. I observed near ubiquitous occurrence of PFASs around the globe, identified increased concentrations in groundwater compared to surface, and highlighted the need for a greater understanding of the temporal exposure to PFAS in surface waters, especially near non-industrial sources like wastewater treatment plants. Next, I quantified the occurrence of twenty-four priority PFASs in two wastewater treatment plants within a semi-arid region of the southern USA over a two-year period to better understand PFAS introduction rates within these systems. I observed higher rates of short-chain compounds compared to legacy PFAS and while hazard assessments for aquatic organisms were not exceeded, effluent concentrations exceeded recently introduced drinking water regulations. Next, I investigated the tissue distributions of both emerging and POPs in three fish encompassing different trophic positions. I observed both PFAS and legacy POP accumulation in all fish, with measured levels of both presenting risk to human consumption based on estimated daily intake values. Lastly, I investigated the occurrence of various HAB toxins across various seasons in twenty reservoirs across a pronounced rainfall gradient. I identified the importance of understanding cyanotoxin exposure at depth, location, and season, including elevated in locations and during times of the year not commonly examined for routine field assessments. This dissertation identified key considerations for how, when, and where environmental exposure is examined, because failure to do so and just follow routine approaches can underestimate water quality risks.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Doctoral

Grantor

Baylor University.

Year dc:date.issued

2024

Author dc:creator

• Stroski, Kevin M., 1994-

Advisor dc:contributor.advisor

• Brooks, Bryan W.

• Exposome.
• Polyfluoroalkyl substances (PFAS)
• Harmful Algal Bloom (HABs)
• Liquid chromatography-mass spectrometry (LC-MS)
• Environmental exposure.
• Water quality.
• Contaminants of emerging concern (CEC)
• Persistent organic pollutants (POP)
• Occurrence.
• Temporal aquatic exposure.
• Cyanotoxin exposure.

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/2104/13590

OAI identifier oai:identifier

oai:baylor-ir.tdl.org:2104/13590