Investigating volatile organic compound composition in Houston, Texas amidst an atmospheric regime shift.

The World Health Organization links ~ 7 million premature deaths per year to poor air quality, underscoring the importance of understanding air pollution sources. Urban areas, with dense populations and diverse activities, significantly impact air quality and, consequently, public health. Volatile organic compounds (VOCs) are a key component of urban air quality, emitted from anthropogenic and biogenic sources. Over decades, researchers have characterized VOC emission sources to better understand their role in forming ozone and secondary organic aerosol (SOA). Historically, VOCs from fossil fuel combustion, especially transportation, have been considered major contributors to ozone and SOA formation. However, the decline in automotive VOCs in recent years due to stricter tailpipe regulations has caused other petrochemical VOC sources to grow in relative importance to urban emission inventories. These non-combustion sources, known as volatile chemical products (VCPs), include organic solvent-based personal care products, cleaning agents, and industrial inks and adhesives. These changes in emission inventories highlight a substantial shift from historical VOC source profiles and represents a new challenge in identifying the VOC emission sources leading to sustained air pollution. Houston, Texas, a hub for national petrochemical processing, offers a unique region to study VCPs. Supporting the Houston-based Dept. of Energy-led Tracking Aerosol Convection ExpeRiment (TRACER) project, VOCs were collected on aerial and ground-based platforms to investigate VCPs in the region. In TRACER-Tethersonde (August 2022), a modular VOC sampler was fabricated for flights on two uncrewed aerial platforms, the ARM tethered balloon system and a drone (Chapter Two). The sampler collected VOCs via sorbent tubes, helping to address knowledge gaps in the vertical distribution of VCPs. In September 2021 and 2022 (i.e., TRACER-Air Quality 1 and 2), ground-based VOC measurements were collected at the San Jacinto Battleground State Historic Site, located along the Houston Shipping Channel (Chapter Three). Using proton transfer reaction mass spectrometry, these measurements focused on three known VCP components, capturing temporal variability and evaluating potential VOC sources. This dissertation assesses the VCP variability, highlighting the importance of further characterization as the urban airshed continues to evolve in response to a changing climate and shifts in human activities.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Doctoral

Grantor

Baylor University.

Year dc:date.issued

2025

Author dc:creator

• Guagenti, Meghan, 1995-

Advisor dc:contributor.advisor

• Usenko, Sascha.

• Public health.
• Premature deaths.
• Air pollution sources.
• Volatile organic compands (VOC)
• VOC emission sources.
• Urban air quality.
• Dense populations.
• Ozone forming.
• Secondary organic aerosol (SOA)
• Diverse activities.
• Volatile chemical products (VCPs)
• Tracking aerosol convection experiment (TRACER) project.

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/2104/13764

OAI identifier oai:identifier

oai:baylor-ir.tdl.org:2104/13764