Characterization of jet fuel exposure in military personnel

This dissertation characterizes inhalation exposure to jet propulsion fuel 8 (JP8) among Air Force (AF) personnel as they perform their routine job tasks, identifies predictors of exposure, and evaluates the utility of biomarkers of exposure to JP8 (urinary metabolites of naphthalene and unmetabolized components of JP8 in exhaled breath).;Workers (n=24) were recruited from an active USAF base and assigned a priori to low, moderate, and high exposure groups. Breathing-zone air and dermal samples were collected over three consecutive workdays and analyzed for total hydrocarbons (THC), benzene, toluene, ethylbenzene, xylenes (BTEX), and naphthalene. Urine (analyzed for 1- and 2-naphthol) and exhaled breath (analyzed for n-hexane, BTEX, naphthalene) samples were collected during the same days. Chapter 2 (paper 1) examines inhalation exposure to JP8. While a priori exposure groups were useful in distinguishing breathing-zone JP8 exposure levels, task based categories were a stronger predictor of JP8 exposure and should be considered for use in epidemiologic studies to minimize the potential for exposure misclassification. Among highly exposure workers, job tasks (e.g., searching for leaks in fuel tank) influenced JP8 exposure. There is potential for full-shift exposure levels to exceed the occupational exposure limit of 200 mg/m3 when workers do not wear respirators inside of the fuel tank. The strong correlation of breathing-zone THC with naphthalene suggests that naphthalene may be an appropriate surrogate of exposure to JP8.;Chapters 3 and 4 (papers 2-3) examine biomarkers of exposure to JP8. A priori exposure group and breathing-zone naphthalene were both significant predictors of post-shift urinary naphthols. Job-related factors (e.g., wearing gloves) were found to influence post-shift naphthol levels among highly exposed workers. The half-lives of 1- and 2-naphthol were estimated as 25 and 43 hours, respectively.;We investigated the utility of exhaled breath versus urinary biomarkers as surrogates of exposure. A priori exposure group and breathing-zone THC were significant predictors for some post-shift exhaled breath analytes, and urinary naphthols weakly to moderately correlate with these analytes. Urinary naphthols are useful surrogates of exposure to JP8 over the work-shift, while exhaled breath analytes may be more useful for measuring exposure directly after short-term exposure.