Physicochemical and Toxicological Assessment of the Semi-volatile and Non-volatile Fractions of Pm from Heavy- Duty Vehicles Operating with and without Emissions Control Technologies

Figure 4-7 Time series of surface diameter (Ds), surface concentration (EAD signal and total particle concentration (DMS count) for a) DPX; b) Baseline-UDDS run.. Figure 5-3 (a) Emission factors of PAHs, hopanes and steranes of baseline and control device-equipped vehicles in UDDS cycle. (b) Emission factors of n-alkanes and acids of baseline and control device-Figure 5-4 (a) Emission factors of PAHs, hopanes and steranes of baseline and control device-equipped vehicles in cruise cycle. (b) Emission factors of n-alkanes and acids of baseline and control device-equipped vehicles in cruise cycle.. Comparison of the ratios of PAHs, hopanes and steranes to organic carbon emission factors in μg/g from baseline and controlled vehicles. (a) running on UDDS cycle. (b) cruise cycle. (c) Ratios of PAHs, hopanes and steranes to organic carbon emission factors in μg/g as reported by Riddle et al., Figure 6-3a,b,c: DTT consumption per unit distance (in n-moles min-1 km-1) traveled by vehicles for Cruise and UDDS cycles and per hour(in n-moles min-1 hr-Figure 6-4 Reactive Oxygen Species (ROS) activity of PM from the tested vehicles, expressed as (a) per mass of PM, and (b) per km (or hr for idle) of vehicle driven.. Abstract This final report presents the investigation results of the CARB vehicle emissions study, with focus on the physicochemical and toxicological properties of the semi-volatile and non-volatile fractions of PM from heavy duty diesel vehicles, operating with and without emissions control technologies. A wide variety of diesel fuelled vehicles, representing the current in-use fleet, have been tested in the California Air Resources Board's (CARB) heavy-duty diesel emission testing laboratory (HDETL) in downtown Los Angeles, including a 1998 Kenworth truck, a diesel hybrid electric bus, a school bus, and a Caltrans truck on three driving cycles, i.e. steady state cruise (50mph), transient [EPA urban dynamometer driving schedule (UDDS)] and idle to simulate various real-world driving conditions. The tested emission control devices include a Continuously Regenerating Technology (CRT); CRT in combination with a selective catalytic reduction system (Zeolite or vanadium based SCRTs) etc. Detailed physico-chemical and toxicological characteristics of PM were measured for each vehicle and driving cycle, including physical properties (e.g. PM mass and size distribution), chemical (EC, OC, organic compounds, trace elements, inorganic ions) and toxicological [dithiothreitol (DTT) and macrophage reactive oxygen species (ROS) assays] characterization of the collected PM samples. Substantial reduction in PM mass emissions (>90%) was accomplished for the tested vehicles operating with advanced …