Honors Theses
Date of Award
Spring 5-8-2027
Document Type
Undergraduate Thesis
Department
Chemistry and Biochemistry
First Advisor
Courtney Roper
Second Advisor
James Stewart
Third Advisor
Brandon Nabors
Relational Format
Dissertation/Thesis
Abstract
Air pollution, especially fine particulate matter (PM₂.₅) and its components such as black carbon (BC), is a major environmental health concern due to its associations with respiratory disease, cardiovascular outcomes, and premature mortality. This study investigated BC concentrations and associated cancer and non-cancer health risks across selected urban and non-urban locations in Alabama.
PM₂.₅ filters were collected every three days from ten monitoring sites in Alabama between January and December 2014. BC concentrations were measured from collected filters using an optical transmissometer at 880 nm. Concentrations were calculated using light attenuation, filter area, sampling time, and flow rate. Health risk assessment was conducted using the U.S. Environmental Protection Agency human health risk assessment framework, including hazard identification, dose–response assessment, exposure assessment, and risk characterization. Chronic daily intake (CDI) was calculated for both children (ages 6–12) and adults (ages 21–70), followed by estimates of lifetime cancer risk (CR) and hazard quotient (HQ).
Results showed that average annual BC concentrations ranged from 2.28 to 3.18 μg/m³ across all sites, with no statistically significant differences observed between urban and non-urban locations. Cancer risk estimates exceeded the acceptable threshold of 1 × 10⁻⁴ at all sampling sites for both children and adults, indicating a potential carcinogenic risk associated with long-term BC exposure. In contrast, all HQ values remained below 1, suggesting that non-cancer adverse health effects are unlikely at the observed exposure levels. However, HQ values were consistently higher for children than adults across all locations.
The study concludes that BC exposure in Alabama presents a consistent cancer risk across both urban and non-urban environments, despite the absence of significant spatial differences in concentration. While non-cancer risks remain below regulatory concern thresholds, elevated cancer risk estimates highlight the need for continued monitoring and mitigation of BC emissions. These findings support the importance of targeted air quality management strategies and further research incorporating improved exposure assessment methods, such as personal monitoring, to better understand population-level health risk.
Recommended Citation
Lee, Emma G., "Black Carbon Pollution in Alabama: Concentration Patterns and Human Health Risk Assessment" (2027). Honors Theses. 3613.
https://egrove.olemiss.edu/hon_thesis/3613
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