Real-time and integrated measurement of potential human exposure to particle-bound polycyclic aromatic hydrocarbons (PAHs) from aircraft exhaust.

We used real-time monitors and low-volume air samplers to measure the potential human exposure to airborne polycyclic aromatic hydrocarbon (PAH) concentrations during various flight-related and ground-support activities of C-130H aircraft at an Air National Guard base. We used three types of photoelectric aerosol sensors (PASs) to measure real-time concentrations of particle-bound PAHs in a break room, downwind from a C-130H aircraft during a four-engine run-up test, in a maintenance hangar, in a C-130H aircraft cargo bay during cargo-drop training, downwind from aerospace ground equipment (AGE), and in a C-130H aircraft cargo bay during engine running on/off (ERO) loading and backup exercises. Two low-volume air samplers were collocated with the real-time monitors for all monitoring events except those in the break room and during in-flight activities. Total PAH concentrations in the integrated-air samples followed a general trend: downwind from two AGE units > ERO-loading exercise > four-engine run-up test > maintenance hangar during taxi and takeoff > background measurements in maintenance hangar. Each PAH profile was dominated by naphthalene, the alkyl-substituted naphthalenes, and other PAHs expected to be in the vapor phase. We also found particle-bound PAHs, such as fluoranthene, pyrene, and benzo[a]pyrene in some of the sample extracts. During flight-related exercises, total PAH concentrations in the integrated-air samples were 10-25 times higher than those commonly found in ambient air. Real-time monitor mean responses generally followed the integrated-air sample trends. These monitors provided a semiquantitative temporal profile of ambient PAH concentrations and showed that PAH concentrations can fluctuate rapidly from a baseline level < 20 to > 4,000 ng/m(3) during flight-related activities. Small handheld models of the PAS monitors exhibited potential for assessing incidental personal exposure to particle-bound PAHs in engine exhaust and for serving as a real-time dosimeter to indicate when respiratory protection is advisable.

Improved high-performance liquid chromatographic method for the determination of polycyclic aromatic hydrocarbon metabolites in human urine.

A reversed-phase HPLC method with fluorescence detection was evaluated for utility in determination of urinary metabolites of polycyclic aromatic hydrocarbons as biomarkers of environmental exposure. The method, which was developed for use in studies of high-level occupational exposure, was found to be unreliable for relatively low-level environmental exposures. The method was modified to include quantitation by standard addition in order to compensate for matrix effects at levels as low as 0.1 ng/ml. The standard addition modification increased both qualitative and quantitative performance, with recovery of 1-hydroxypyrene spikes improved from 164% to 114% at 0.36 ng/ml. The modified method was successfully applied in an environmental exposure study.