Real-world vehicle emissions: a summary of the Seventeenth Coordinating Research Council On-Road Vehicle Emissions Workshop.

The Coordinating Research Council, Inc. (CRC) held its 17th On-Road Vehicle Emissions Workshop in March 2007, where results of the most recent on-road vehicle emissions research were presented. We summarize ongoing work from researchers who are engaged in improving our understanding of the role and contribution of mobile sources to ambient air quality and emission inventories. Participants in the Workshop discussed efforts to improve mobile source emission models, light- and heavy-duty vehicle emissions measurements, on- and off-road emissions measurements, effects of fuels and lubricating oils on emissions, as well as emerging issues and topics for future research.

Real-world vehicle emissions: a summary of the Sixteenth Coordinating Research Council On-Road Vehicle Emissions Workshop.

The Coordinating Research Council held its 16th workshop in March 2006, with 83 presentations describing the most recent mobile source-related emissions research. In this paper, we summarize the presentations from researchers who are engaged in improving our understanding of the contribution of mobile sources to air quality. Participants in the workshop discussed evaluation of in-use emissions control programs, effects of fuels on emissions, emission models and emission inventories, results from gas- and particle-phase emissions studies from spark-ignition and diesel-powered vehicles, and efforts to improve our capabilities in performing on-board emissions measurements, as well as topics for future research.

Real-world vehicle emissions: A summary of the 15th coordinating research council on-road vehicle emissions workshop.

The Coordinating Research Council held its 15th workshop in April 2005, with nearly 90 presentations describing the most recent mobile source-related emissions research. In this paper, the authors summarize the presentations from researchers who are engaged in improving our understanding of the contribution of mobile sources to air quality. Participants in the workshop discussed emission models and emission inventories, results from gas- and particle-phase emissions studies from spark-ignition and diesel-powered vehicles (with an emphasis in this workshop on particle emissions), effects of fuels on emissions, evaluation of in-use emissions control programs, and efforts to improve our capabilities in performing on-board emissions measurements, as well as topics for future research.

Characterization of atmospheric mineral components of PM2.5 in Beijing and Shanghai, China.

Weekly PM2.5 samples were collected for one year in Beijing and Shanghai and the crustal elements analyzed to investigate the concentration levels and temporal variations of ambient fine mineral dust. The mass concentrations of Al, Si, Ca, Mg, and Fe exhibited similar significant weekly variations in both Beijing and Shanghai. The annual average PM2.5 concentrations of major crustal elements ranged from 0.27 microg m-3 Mg to 2.48 microg m-3 Si in Beijing, which were 1.40-2.24 times higher than those in Shanghai. Their PM-weighted values were comparable between the two cities. A distinct seasonal pattern was present for these crustal elements with the highest concentrations during the spring in Beijing and during the winter in Shanghai, and the lowest concentrations during the summer in both cities. During the dusty spring of 2000 in Beijing, soil dust was the second most abundant PM2.5 constituent with a contribution as high as 18.6%, over twice that in the winter. The highest fine soil concentration (37.8 microg m-3) and mass percentage (41.6%) occurred in the same week of intensive dust events impacting Beijing. The impact of dust storms complicates the goal of reducing PM2.5 in Beijing. Ca originating from construction activities appears to be a significant PM2.5 contributor as well.

Characterization of carbonaceous species of ambient PM2.5 in Beijing, China.

One-week integrated fine particulate matter (i.e., particles <2.5 microm in diameter; PM2.5) samples were collected continuously with a low-flow rate sampler at a downtown site (Chegongzhuang) and a residential site (Tsinghua University) in Beijing between July 1999 and June 2000. The annual average concentrations of organic carbon (OC) and elemental carbon (EC) at the urban site were 23.9 and 8.8 microg m(-3), much higher than those in some cities with serious air pollution. Similar weekly variations of OC and EC concentrations were found for the two sampling sites with higher concentrations in the winter and autumn. The highest weekly variations of OC and EC occurred in the winter, suggesting that combustion sources for space heating were important contributors to carbonaceous particles, along with a significant impact from variable meteorological conditions. High emissions coupled with unfavorable meteorological conditions led to the max weekly carbonaceous concentration the week of November 18-25, 1999. The weekly mass ratios of OC:EC ranged between 2 and 4 for most samples and averaged 2.9, probably suggesting that secondary OC (SOC) is present most weeks. The range of contemporary carbon fraction, based on the C14 analyses of eight samples collected in 2001, is 0.330-0.479. Estimated SOC accounted for approximately 38% of the total OC at the two sites. Average OC and EC concentrations at Tsinghua University were 25% and 18%, respectively, higher than those at Chegongzhuang, which could be attributed to different local emissions of primary carbonaceous particles and gaseous precursors of SOC, as well as different summer photochemical intensities between the two locations.

Real-world vehicle emissions: a summary of the 14th coordinating research council on-road Vehicle Emissions Workshop.

The Coordinating Research Council held its 14th Vehicle Emissions Workshop in March 2004, where results of the most recent on-road vehicle emissions research were presented. We summarize ongoing work from researchers who are engaged in improving our understanding of the contribution of mobile sources to ambient air quality and emission inventories. Participants in the workshop discussed efforts to improve mobile source emission models, light- and heavy-duty vehicle emissions measurements, on- and off-road emissions measurements, effects of fuels and lubricating oils on emissions, as well as topics for future research.

Innovative methods for emission inventory development and evaluation: workshop summary.

Emission inventories are an essential tool for evaluating, managing, and regulating air pollution. Refinements and innovations in instruments that measure air pollutants, models that calculate emissions, and techniques for data management and uncertainty assessment are needed to enhance emission inventories. This workshop provided recommendations for improving emission factors, improving emission models, and reducing inventory uncertainty. Communication that increases cooperation between developers and users of inventories is essential. Emission inventories that incorporate these improvements will meet the challenges of the future.

Real-world vehicle emissions: a summary of the Thirteenth Coordinating Research Council On-Road Vehicle Emissions Workshop.

The Coordinating Research Council held its thirteenth Vehicle Emissions Workshop in April 2003, when results of the most recent on-road vehicle emissions research were presented. Ongoing work from researchers who are engaged in improving understanding of the contribution of mobile sources to ambient air quality and emission inventories is summarized here. Participants in the workshop discussed efforts to improve mobile source emission models, the role of on-board diagnostic systems in inspection and maintenance programs, light- and heavy-duty vehicle emissions measurements, on- and off-road emissions measurements, effects of fuels and lubricating oils on emissions, as well as topics for future research.

Real-world vehicle emissions: a summary of the Eleventh Coordinating Research Council On-Road Vehicle Emissions Workshop.

The Coordinating Research Council (CRC) held its eleventh workshop in March 2001, focusing on results from the most recent real-world vehicle emissions research. We summarize the presentations from researchers engaged in improving our understanding of the contribution of mobile sources to ambient air quality and emission inventories. Participants in the workshop discussed efforts to improve mobile source emission models and emission inventories, the role of on-board diagnostic (OBD) systems in inspection and maintenance (I/M) programs, particulate matter (PM) emissions, contributions of diesel vehicles to the emission inventory, on-road emissions measurements, fuel effects, unregulated emissions, and microscale and modal emission models, as well as topics for future research.

Real-world vehicle emissions: a summary of the twelfth Coordinating Research Council On-Road Vehicle Emissions Workshop.

The Coordinating Research Council (CRC) held its 12th workshop in April 2002, with nearly 90 presentations on the most recent on-road vehicle emissions research. This paper summarizes the presentations from researchers who are engaged in improving understanding of the contribution of mobile sources to air quality. Participants in the workshop discussed mobile source emission models and emission inventories, results from gas- and particle-phase emissions studies from spark-ignition and diesel-powered vehicles (with an emphasis in this workshop on particle emissions), effects of fuels on emissions, evaluation of in-use emissions control programs, and efforts to improve our capabilities in performing on-board emissions measurements, as well as topics for future research.

Real-World Vehicle Emissions: A Summary of the 18th Coordinating Research Council On-Road Vehicle Emissions Workshop.

The Coordinating Research Council (CRC) convened its 18th On-Road Vehicle Emissions Workshop March 31- April 2, 2008, with 104 presentations describing the most recent mobile source-related emissions research. In this paper we summarize the presentations from researchers whose efforts are improving our understanding of the contribution of mobile sources to air quality. Participants in the workshop discussed emission models and emissions inventories, results from gas- and particle-phase emissions studies from spark-ignition and diesel-powered vehicles (with an emphasis in this workshop on particle emissions), effects of fuels on emissions, evaluation of in-use emission-control programs, and efforts to improve our capabilities in performing on-board emissions measurements, as well as topics for future research.

Analysis of Remote Sensing Errors of Omission and Commission Under FTP Conditions.

Second-by-second modal emissions data from a 73-vehicle fleet of 1990 and 1991 light duty cars and trucks driven on the Federal Test Procedure (FTP) driving cycle were examined to determine remote sensing errors of commission in identifying high emissions vehicles. Results are combined with a similar analysis of errors of omission based on modal FTP data from high emissions vehicles. Extremely low errors of commission combined with modest errors of omission indicate that remote sensing should be very effective in isolating high CO and HC emitting vehicles in a fleet of late model vehicles on the road.

Real-World Vehicle Emissions: A Summary of the Sixth Coordinating Research Council On-Road Vehicle Emissions Workshop.

The Coordinating Research Council (CRC) has conducted a series of workshops on real-world vehicle emissions. This article summarizes findings from the most recent research regarding on-road emissions from mobile sources, presented at the CRC workshop held in March 1996. Among the topics discussed were efforts to improve and update emission models, results from field studies designed to understand the contribution of mobile sources to emission inventories, results from gas-and particle-phase emissions studies from in-use motor vehicles, and areas of future research. The Sixth Coordinating Research Council (CRC) On-Road Vehicle Emissions Workshop was held March 18-20, 1996, in San Diego, CA. More than 160 representatives from academia, industry, government, and consulting firms in the United States, Canada, and Europe participated in the three-day meeting. The objective of the Workshop was to present the most recent information from research programs on: mobile source contributions to the emission inventory emission factor models and activity data model comparison and development emission reduction programs new developments in remote sensing studies of on-road vehicle exhaust and non-tailpipe emissions off-cycle Federal Test Procedure (FTP) studies and revisions to the FTP particle emissions from the light- and heavy-duty fleets future research needs Nine sessions were devoted to vehicle emissions models, improvements to the emission inventory, on-road and tunnel studies, off-cycle emissions, non-tailpipe and diesel emissions, emission reduction programs, and remote sensing. Overall workshop coordination was provided by Timothy Belian and the CRC staff, with Steven Cadle and Robert Gorse serving as cochairmen. Individual session chairmen were Brent Bailey (National Renewable Energy Laboratory), Mark Carlock (California Air Resources Board), Harold Haskew (General Motors), Kenneth Knapp and Philip Lorang (U.S. Environmental Protection Agency), Douglas Lawson (Colorado State University), Alan Lloyd (Desert Research Institute), Robert Slott (Shell Oil), and Timothy Truex (University of California, Riverside). In addition, during the Workshop, Lesha Hrynchuk of the California Air Resources Board (CARB) presented a hands-on demonstration using the Internet to obtain motor vehicle emissions information from groups throughout the world. The complete Workshop proceedings are available from the Coordinating Research Council, 219 Perimeter Center Parkway, Atlanta, GA 30346; phone: (770) 396-3400; fax: (770) 396-3404. The following summarizes each session and includes a short synopsis of all the papers that were presented.

Real-World Vehicle Emissions: A Summary of the Seventh Coordinating Research Council On-Road Vehicle Emissions Workshop.

The Coordinating Research Council (CRC) has sponsored a series of workshops over the last decade focusing on the most recent research on real-world vehicle emissions. This summary presents findings from the latest workshop by researchers engaged in improving our understanding of the contribution of mobile sources to air quality. Participants in the workshop discussed efforts to evaluate and improve mobile source emission models, field programs designed to understand the contribution of mobile sources to emission inventories, and results from gas- and particle-phase emissions studies from spark-ignition and diesel-powered vehicles, as well as topics for future research.

Real-World Vehicle Emissions: A Summary of the Eighth Coordinating Research Council On-Road Vehicle Emissions Workshop.

The Coordinating Research Council (CRC) has sponsored a series of workshops over the last decade focusing on the most recent real-world vehicle emissions research. This summary presents findings from the eighth CRC-sponsored workshop from researchers who are engaged in improving our understanding of the contribution of mobile sources to air quality. Participants in the workshop discussed efforts to evaluate and improve mobile source emission models, field programs designed to understand the contribution of mobile sources to emission inventories, results from gas- and particle-phase emissions studies from spark-ignition and diesel-powered vehicles, as well as topics for future research.

[Characteristics and sources of trace elements in ambient PM2.5 in Beijing].

To understand concentration levels and sources of trace elements in PM2.5(particulate matter with aerodynamic diameters less than 2.5 microns) concentration and composition in the ambient air of Beijing, weekly samples were simultaneously collected for one year in Chegongzhuang and Qinghuayuan. Trace elements exhibited similar significant weekly variations. The strongest weekly shift occurred in winter, which reached as high as a factor of 1.6 for two consecutive weeks. No obvious seasonal pattern was found for trace elements except for that their average concentrations were much higher in winter. The EFs of trace elements were lowest in spring, probably due to frequent dust storms resulting in reduced contribution of anthropogenic sources and increased contribution of soil dust. The ambient concentrations of Se, Br, and Pb were about 1000-8000 times higher than those expected from the crustal soil in Beijing. Se was most enriched in PM2.5, reflecting the characteristics of fine particles from coal burning in Beijing. The annual mean concentration of Pb of 0.31 microgram.m-3 did not exceeded the WHO annual standard, but was at very high level compared to those measured in Los Angles and Brisbane. Comparison analysis of Pb with Br and Se shows that coal burning is probably another major source of Pb in PM2.5 other than vehicle emission.

[Characteristics of mineral component in ambient PM2.5 in Beijing].

To understand the concentration levels and temporal variations of the mineral component of PM2.5 in the ambient air of Beijing, weeklong samples were simultaneously collected for one year at Qinghuayuan and Chegongzhuang. The concentrations of five major crustal elements Al, Si, Ca, Mg, and Fe exhibited similar significant weekly variations, with their maximum values in the week of a serious dust event in the spring of 2000. Obvious seasonal pattern was also found for these elements, indicating different influences on fine mineral particles from the source emissions and meteorology in different seasons. Soil dust concentration increased from a low level in summer to the peak value (21.1 microg x m(-3)) in spring, suggesting that frequent dust events made a significant contribution to fine soil dust. A large number of construction activities in Beijing substantially increased the loading of fine calcium-bearing particles, and their emissions thus need to be further controlled.

An Experimental Evaluation of Remote Sensing-Based Hydrocarbon Measurements: A Comparison to FID Measurements.

The purpose of this study was to intercompare hydrocarbon (HC) measurements performed by a number of different instruments: a gas chromatograph (GC), a flame ionization detector (FID), a fourier transform infrared spectrometer (FTIR), a commercially produced non-dispersive infrared analyzer (NDIR), and two remote sensors. These instruments were used to measure total HC concentrations in a variety of samples, including (1) ten different individual HC species, (2) 12 different vehicle exhaust samples, and (3) three different volatilized fuel samples. The 12 exhaust samples were generated by operating two different vehicles on a dynamometer. Each vehicle was operated at different times with three different fuels. The vehicles were operated fuel rich, i.e., with low air/fuel ratios to encourage elevated exhaust HC levels. Some of the exhaust samples were obtained while operating each vehicle at a stoichiometric air/fuel ratio with one spark plug wire disconnected. To quantify the degree to which the various instruments agreed with the FID, a parameter called the response factor was used, where the response factor was defined as the HC/CO2 ratio measured by each instrument divided by the HC/CO2 ratio measured by the dynamometer bench. Of the various instruments, only the GC yielded response factors that were consistently at or close to one. The other instruments typically had values at or below one. For the ten individual HC species studied, the NDIR and remote sensors obtained response factors between 0.05 and 1.0, with the highest response factors being obtained for the alkanes and the lowest response factors obtained for toluene and ethylene. For the exhaust samples, the NDIR and remote sensors obtained response factors between 0.23 and 0.68. For raw fuel samples, the response factors were between 0.44 and 0.68. NDIR and remote sensor measurements correlated very poorly with total HC in exhaust.

Light-Duty Motor Vehicle Exhaust Particulate Matter Measurement in the Denver, Colorado, Area.

A study of particulate matter (PM) emissions from in-use, light-duty vehicles was conducted during the summer of 1996 and the winter of 1997 in the Denver, CO, region. Vehicles were tested as received on chassis dynamometers on the Federal Test Procedure Urban Dynamometer Driving Schedule (UDDS) and the IM240 driving schedule. Both PM10 and regulated emissions were measured for each phase of the UDDS. For the summer portion of the study, 92 gasoline vehicles, 10 diesel vehicles, and 9 gasoline vehicles with visible smoke emissions were tested once. For the winter, 56 gasoline vehicles, 12 diesel vehicles, and 15 gasoline vehicles with visible smoke were tested twice, once indoors at 60 °F and once outdoors at the prevailing temperature. Vehicle model year ranged from 1966 to 1996. Impactor particle size distributions were obtained on a subset of vehicles. Continuous estimates of the particle number emissions were obtained with an electrical aerosol analyzer. This data set is being provided to the Northern Front Range Air Quality Study program and to the State of Colorado and the U.S. Environmental Protection Agency for use in updating emissions inventories.