Abstract View
In-vitro Cytotoxicity of Lab-generated Tunable Soot: Insight into Military Burn Pit Contribution to Chronic Multisymptom Illnesses (CMI)
DHRUV MITROO, Durgesh Das, Benjamin Kumfer, Nathan Ravi, Veterans Research and Education Foundation
Abstract Number: 267
Working Group: Health-Related Aerosols
Abstract
Whether released during unpredictable events, such as oil-well fires, or through routine activity, such as military burn pit operation, combustion emissions are problematic for the long-term health of military personnel. Deployed military preventive medicine units evaluating the presence of airborne toxins at forward operating bases (FOBs) have reported polycyclic aromatic hydrocarbons (PAHs) and dioxins, in both aerosol and gas-phase, originating from military burn pits. Importantly, cohort studies have associated burn pit emissions with chronic multisymptom illnesses (CMI); unsurprising given the pits’ sustained use and proximity to barracks. Thus far, the molecular pathway through which burn pit emissions lead to CMI remains unclear, thwarting the exploration of therapeutic (or preventive) options. The problem is made more complicated by the wide variation in chemical composition and physical properties of carbonaceous particles generated in open and variable combustion systems. To address these issues, we utilized a bench-top soot generator comprising an ethylene tri-flow burner and a control panel, that uses different flame structures to produce carbonaceous aerosols with tunable properties. We tailored the combustion conditions, i.e., temperature, fuel and oxidizer mixtures, and flame type (premixed and non-premixed), to generate soot with varying properties, such as size, surface area, EC/OC, and PAH loading, characteristic of military burn pit emissions. Herein we present initial physical and chemical characterization results for produced aerosol (soot), measurements of its stability in solution, and descriptions of its cytotoxic effects on human cell lines. The cytotoxicity results illuminate how the aryl hydrocarbon receptor (AhR) may be involved in influencing the elimination or potentiating PAH’s toxicity. While the work presented is centered on replicating military bun pit emissions, we note that our soot generator can be used to create standards of different types of soot geared towards understanding combustion aerosol pollution in general.