Search Results

A recently completed program was developed to evaluate ultra-low sulfur diesel fuels and passive diesel particle filters (DPF) in several different truck and bus fleets operating in Southern California. The primary test fuels, ECD and ECD-1, are produced by ARCO, a BP company, and have less than 15 ppm sulfur content. A test fleet comprised of heavy-duty trucks and buses were retrofitted with one of two types of catalyzed diesel particle filters, and operated for one year. As part of this program, a chemical characterization study was performed in the spring of 2001 to compare the exhaust emissions using the test fuels with and without aftertreatment. A detailed speciation of volatile organic hydrocarbons (VOC), polycyclic aromatic hydrocarbons (PAH), nitro-PAH, carbonyls, polychlorodibenzo-p-dioxins (PCDD) and polychlorodibenzo-p-furans (PCDF), inorganic ions, elements, PM10, and PM2.5 in diesel exhaust was performed for a select set of vehicles.

Better information on the comparative toxicity of airborne emissions from different types of engines is needed to guide the development of heavy vehicle engine, fuel, lubricant, and exhaust after-treatment technologies, and to place the health hazards of current heavy vehicle emissions in their proper perspective. To help fill this information gap, samples of vehicle exhaust particles and semi-volatile organic compounds (SVOC) were collected and analyzed. The biological activity of the combined particle-SVOC samples is being tested using standardized toxicity assays. This report provides an update on the design of experiments to test the relative toxicity of engine emissions from various sources.