Tracking personal exposure to particulate diesel exhaust in a diesel freight terminal using organic tracer analysis

Abstract

Personal exposure to particle-phase molecular markers was measured at a trucking terminal in St Louis, MO, as part of a larger epidemiologic project aimed at assessing carbonaceous fine particulate matter (PM) exposure in this occupational setting. The integration of parallel personal exposure, ambient worksite area and ambient urban background (St Louis Supersite) measurements provided a unique opportunity to track the work-related exposure to carbonaceous fine PM in a freight terminal. The data were used to test the proposed personal exposure model in this occupational setting:Personal exposure ¼ urban background þ work site background þ personal activityTo accurately assess the impact of PM emission sources, particularly motor vehicle exhaust, and organic elemental carbon (OCEC) analysis and nonpolar organic molecular marker analysis by thermal desorption-gas chromatography/mass spectrometry (TD-GCMS) were conducted on all of the PM samples. EC has been used as a tracer for diesel exhaust in urban areas, however, the emission profile for diesel exhaust is dependent upon the operating conditions of the vehicle and can vary considerably within a fleet. Hopanes, steranes, polycyclic aromatic hydrocarbons and alkanes were measured by TD-GCMS. Hopanes are source-specific organic molecular markers for lubricating oil present in motor vehicle exhaust. The concentrations of OC, EC and the organic tracers were averaged to obtain average profiles to assess differences in the personal, worksite area and urban background samples, and were also correlated individually by sample time to evaluate the exposure model presented above. Finally, a chemical mass balance model was used to apportion the motor vehicle and cigarette-smoke components of the measured OC and EC for the average personal exposure, worksite area and urban background samples.

Geochemical markers and polycyclic aromatic hydrocarbons in solvent extracts from diesel engine particulate matter

“…5(a) ). However, the presence of hopanes raises the question of whether they come from diesel fuel itself or from engine lubricating oils, as is sometimes assumed (Sheesley et al 2009 ; Huang et al 2013 ). Since these compounds’ molecular weight ranges from 370 to 482 Da, oil fractions used for diesel fuel production (b.p.…”

Lung Cancer and Vehicle Exhaust in Trucking Industry Workers

“…Source apportionment data in the LH drivers, P&D drivers, and dockworkers indicated that most (~ 80% or greater) of the EC was from diesel sources with a smaller percentage from spark-ignition vehicles and lubricating oil (Sheesley et al 2008a). OC source apportionment indicated a substantial mobile source contribution that was mostly attributable to lubricating oil.…”

Highway proximity and black carbon from cookstoves as a risk factor for higher blood pressure in rural China

“…In contrast, average exposure to hopanes, specific tracers of motor vehicle exhaust in our study setting, was significantly higher among women living in the village closest to the highway (median distance = 76 m) compared with those in the village farthest from the highway (median distance = 548 m) (4.6 vs. 1.1 ng/m 3 ; P < 0.001 for both seasons; Table S4). In fact, the average near-highway hopane exposures exceeded occupational levels among US trucking terminal workers (4.6 vs. 1.9 ng/m 3 ) (20).…”