UC Davis experts: Air quality

The following UC Davis faculty members are available to speak on topics related to air quality, such as summer smog, vehicle emissions, and air pollution and human health.

Autos and traffic

Cleaner passenger vehicles

Air-quality, climate-change and energy concerns are motivating a transition from internal-combustion engines to other propulsion technologies. UC Davis has the most prominent and comprehensive university research program in the country on advanced technologies and policy to encourage the use of clean cars. We study systems powered by gasoline-electric hybrids, batteries, fuel cells and clean diesel. Much of the research is based in our Institute of Transportation Studies (ITS-Davis) and the Department of Mechanical and Aeronautical Engineering. Contact: Sylvia Wright, News Service, (530) 752-7704, swright@ucdavis.edu.

Cleaner trucks and buses

California will enforce new and extremely strict emission standards for heavy-duty vehicles such as trucks and buses in 2007. Our Institute of Transportation Studies (ITS-Davis) is evaluating new technologies that employ "clean diesel," hydrogen and fuel-cell systems. In trucks, ITS-Davis is pioneering an effort to reduce diesel emission during idling through the use of fuel-cell auxiliary power units. ITS-Davis is also evaluating clean bus technologies that rely on fuel-cell power, the use of a hydrogen/compressed natural gas (CNG) mixture, and proposed clean-diesel systems. Trucks contact: C.J. Brodrick, ITS-Davis, (530) 752-4122, cjbrodrick@ucdavis.edu. Buses contact: Marshall Miller, ITS-Davis, (530) 752-8758, mmiller@ucdavis.edu.

Traffic-flow modeling

H. Michael Zhang, an associate professor of civil and environmental engineering, studies how traffic flows on freeways; the efficiency of ramp metering; transportation in Yosemite National Park; and modeling vehicle emissions. Contact: H. Michael Zhang, Civil and Environmental Engineering, (530) 754-9203, hmzhang@ucdavis.edu

Autos in developing countries

ITS-Davis Director Dan Sperling, an international authority on automobile emissions, air quality and transportation policy, has co-authored a series of five reports on transport-sector air pollution in developing countries. Sperling writes that without new measures, greenhouse gas emissions from transportation in the developing world will exceed those in the industrialized world sometime after 2010. Many of the strategies that could reduce those emissions would also address the more immediate problems of local air pollution, access to basic transportation and infrastructure financing pressures. The reports were funded by the Pew Center on Global Climate Change. Contact: Daniel Sperling, ITS-Davis, (530) 752-7434, dsperling@ucdavis.edu.

Travel behavior

Patricia Mokhtarian, a professor of civil and environmental engineering, studies telecommuting; drivers' response to traffic congestion; adoption of new transportation technologies; land use and transportation interactions; and the air-quality impacts of transportation management measures. She is a member of the Transportation Subcommittee of the Clean Air Act Advisory Committee of the US Environmental Protection Agency. Contact: Patricia Mokhtarian, Civil and Environmental Engineering, (530) 752-7062, plmokhtarian@ucdavis.edu.

Air pollution

Nanoparticles, combustion and air pollution

Ian Kennedy, a professor of mechanical engineering at the University of California, Davis, studies how very small particles of metal and carbon (soot) -- measured in nanometers, or billionths of a meter -- are formed within flames. These nanoparticles come from burning oil and coal, from processes such as welding, and from diesel engines. They contribute to air pollution and, because of their small size, may play an important role in human health. Contact: Ian Kennedy, Mechanical and Aeronautical Engineering, (530) 752-2796, imkennedy@ucdavis.edu.

Atmospheric chemistry

Although relatively little is known about the chemistry that occurs within atmospheric particles or cloud and fog drops, there is increasing evidence that these particles and water drops are the sites of important and complex interactions. Cort Anastasio, assistant professor in the Department of Land, Air and Water Resources, explores the chemistry of human-produced air pollutants as well as that of the natural "background" atmosphere. His findings should shed light on the fate of toxicants, such as ozone, and the formation of acidic rain. Contact: Cort Anastasio, Land, Air and Water Resources, (530) 754-6095, canastasio@ucdavis.edu.

Indoor air quality

Deborah Bennett studies indoor air quality and measures workers' exposure to pollutants on the job (occupational exposures), both indoors and outdoors. She has investigated agriculture workers' exposure to particulates and gases; and air pollutants in homes. Contact: Deborah Bennett, UC Davis School of Medicine, (530) 754-8282, ldhbennett@ucdavis.edu.

Pollutant interactions and smog

Michael Kleeman, assistant professor of civil and environmental engineering, studies urban and regional air quality problems with an emphasis on the size and composition of atmospheric particles and on gas-to-particle conversion processes. These issues are important because research has found that airborne particles with diameters less than 2.5 microns cause adverse health effects. The size and composition of particles found in the atmosphere also determines much of the haze in large cities. He currently is analyzing air pollution in the Los Angeles area, particularly the relationship between land-origin pollution and sea-origin particles. His insights should help scientists and regulators design more focused emissions-control programs. Contact: Michael Kleeman, Civil and Environmental Engineering, (530) 752-8386, mjkleeman@ucdavis.edu.

Asian dust storms

Thomas Cahill and the UC Davis DELTA Group have made detailed studies of aerosols and global dust storms. Asian dust storms occur every spring. The DELTA Group has shown that they carry desert sand and industrial pollutants across the Pacific. These aerosols make people sick and kill crops in Asia, may be polluting American waters and could affect global climate. http://delta.ucdavis.edu. Contact: Thomas Cahill, DELTA Group, (530) 752-1120, tacahill@ucdavis.edu.

Agriculture and air quality

Professor Robert Flocchini , director of the Crocke r Nuclear Laboratory at UC Davis, studies the particulate matter generated by agricultural practices, including land preparation, land maintenance and harvesting. He also studies the contribution to air pollution of effluent from livestock facilities and is vice chair of a National Academy of Sciences review committee on the subject. Contact: Robert Flocchini, Department of Land, Air and Water Resources, (530) 752-1018, rgflocchini@ucdavis.edu.

Ground Zero air

Thomas Cahill, an international authority on the constituents and transport of airborne particles, leads a team of experts studying the dust and smoke blown through lower Manhattan after the collapse of the World Trade Center. The team has identified unprecedented clouds of very fine particles that should be considered in evaluating rescue workers' and residents' health problems. Cahill, a professor emeritus of physics and atmospheric sciences and a research professor in applied science, heads the UC Davis DELTA Group (for Detection and Evaluation of Long-range Transport of Aerosols), a collaborative association of aerosol scientists at several universities and national laboratories. Contact: Thomas Cahill, DELTA Group, (530) 752-1120, tacahill@ucdavis.edu.

Health issues

Nanoparticles, air pollution, climate and health

Anthony Wexler, an atmospheric scientist at the University of California, Davis, studies how very small particles -- measured in nanometers, or billionths of a meter -- contribute to air pollution and affect human health and climate. The role of these atmospheric nanoparticles is one of the largest unknowns in understanding global climate change, Wexler said. Clouds form when water droplets form around nanoparticles, and the thickness and whiteness of clouds affects how much heat from the sun is reflected back into space. Wexler has developed new equipment for analyzing single nanoparticles in polluted air. He is participating in an Environmental Protection Agency project to monitor air quality in selected cities including Pittsburgh, Pa., Houston, and Fresno, Calif. He also studies how particles of different sizes are carried through the airways into the lungs, and how they can affect human health. Contact: Anthony Wexler, Mechanical and Aeronautical Engineering, (530) 754-6558, aswexler@ucdavis.edu.

Air pollution and lung health

Kent Pinkerton, a professor of anatomy, physiology and cell biology, studies the effects of environmental air pollution on lung structure and function. He investigates the mechanisms by which particulates (dust, air pollution from vehicle emissions) produce toxic effects in the lung; the interaction of gases and airborne particles at specific sites and in specific cell populations of the lungs; and the effects of environmental tobacco smoke on lung growth and development. Contact: Kent Pinkerton, Veterinary Medicine, (530) 752-8334, kepinkerton@ucdavis.edu.

Air pollution, allergies and asthma in children

Pioneering work at the California Regional Primate Research Center at UC Davis is bringing a new understanding of the relationship between air pollution, common allergies and asthma. The research, funded by the National Institutes of Health, has shown for the first time that occasional exposure to the air pollutant ozone can change how the lungs of young rhesus monkeys develop, and lead to a disease similarto childhood asthma in humans. Contacts: Charles Plopper, School of Veterinary Medicine, (530) 752-1174, cgplopper@ucdavis.edu; Dallas Hyde, School of Veterinary Medicine, (530) 752-6865, dmhyde@ucdavis.edu; Jesse Joad, UC Davis Medical Center, (916) 734-3189, jpjoad@ucdavis.edu.

Forests

Urban forests

The Center for Urban Forest Research at UC Davis partners with government foresters, university researchers and others to describe the structure of urban forests -- vegetation planted in cities -- and quantify related benefits and costs. Some studies are exploring the role of urban forests in pollutant uptake, reducing evaporative hydrocarbon emissions by shading cars in parking lots, and removing carbon dioxide from the air. http://wcufre.ucdavis.edu/. Contact: Greg McPherson, Center for Urban Forest Research, (530) 752-5897, egmcpherson@ucdavis.edu.

Smog in the Sierra

John Carroll, a professor of meteorology in the Department of Land, Air and Water Resources, studies the exposure of forests and lakes in the Sierra Nevada to several air pollutants. As air passes over industrialized and high-population areas, air pollutants are constantly added, so the highest total loading is found downwind of the source areas. For example, air flowing from the Pacific Ocean through the San Francisco Bay Area and the Sacramento area arrives over the Sierra Nevada foothills with concentrations of urban and agricultural pollutants. One finding: The summer smog plume from Sacramento does not reach the Sierra crest in one day but is mixed into larger, regional air masses, degrading regional air quality. When pollutants from central California do enter the Tahoe basin, they have concentrations about 1/3rd to 1/4th of those seen over the foothills to the west. Contact: John Carroll, Land, Air and Water Resources, (530) 752-3245, jjcarroll@ucdavis.edu.

National parks

Researchers at Crocker Nuclear Laboratory at UC Davis operate the national IMPROVE (Interagency Monitoring for Protected Visual Environments) particulate monitoring network, which helps preserve visibility at U.S. national parks and wilderness areas. The Crocker lab operates air-sampling instruments in the parklands and processes the data. Contact: Robert Flocchini, Department of Land, Air and Water Resources, (530) 752-1018, rgflocchini@ucdavis.edu.

Media contact

Sylvia Wright, PIO for environmental science and policy, (530) 752-7704, swright@ucdavis.edu.

Top of page

Last updated April 21, 2008