Differential Metabolite Expressions in Firefighters Induced by Fireground Exposure: A Comparative Metabolomics Analysis
Publisher
The University of Arizona.Rights
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Release after 10/19/2025Abstract
Firefighters are regularly exposed to known or probable carcinogens, including polycyclic aromatic hydrocarbons (PAHs), benzene, formaldehyde, phthalates, and other harmful substances. This exposure occurs mainly through inhalation of smoke released during fire events and dermal exposure. Consequently, firefighters face a higher risk of selected cancers, such as bladder cancer. The International Agency for Research on Cancer (IARC) classified firefighters' occupational exposure as carcinogenic to humans, but there is still a lack of mechanistic evidence on what and how fireground exposure elevates cancer risks and the relationship between fireground exposure and metabolite expression in humans remains poorly understood. Research is also limited regarding the differences between wildland-urban interface (WUI) firefighting and structure fires concerning the biological response in firefighters. Additionally, there is a need to understand how women firefighters respond differently to fireground exposure compared to men firefighters. To address these gaps, we bring together three projects involving male and women firefighters, exposed to various types of fires. Powered by the high-resolution metabolomics pipeline and the high-resolution liquid-chromatography mass-spectrometry (LC-MS) platform, these projects aim to evaluate the impact of fireground exposure on firefighters' metabolisms, together with other important factors for firefighters: Project 1 assesses changes in the urinary metabolome by Hispanic ethnicity among male firefighters respond to structure fires. Prior to project 1, we developed an analytical pipeline for urine-based metabolomics, which was applied to investigate the effect of fireground exposure (prior analysis) and ethnicity (project 1) on metabolome as disparity in cancer risk has been observed among Hispanic and non-Hispanic firefighters. Two publications have been produced from project 1, titled “Evaluating changes in firefighter urinary metabolomes after structural fires: an untargeted, high-resolution approach” and “Differential metabolic profiles by Hispanic ethnicity among male Tucson firefighters”. Project 2 assesses changes in the urinary metabolome by fireground exposure in male firefighters responding to WUI fires. WUI fires differ from structure fires in that they introduce a much more complex exposure matrix due to the involvement of both wildland biomass and built materials. We also tried to compare the metabolic responses across different fire types, looking for unique and shared biological responses that might understand prevalent conditions among these firefighters. One manuscript has been produced based on project 2 which is being peer reviewed as of the time of dissertation process. Project 3 assesses changes in the urinary metabolome by training fire exposures in women firefighters. Project 3 investigates metabolic responses to training fire exposures among women firefighters, differing from previous projects in both exposure matrix and population. Although training fires are resembling structure fires regarding burning materials, they are intrinsically different in fire intensity and participants activities. We also compared metabolic responses by fire exposure across two populations (genders).Type
textElectronic Dissertation
Degree Name
Ph.D.Degree Level
doctoralDegree Program
Graduate CollegePublic Health