Aerosol Laboratory-University of Southern California
The major objective of our work at the USC Aerosol Lab is to investigate the underlying mechanisms that produce the health effects associated with exposure to air pollutants generated by a variety of sources, such as traffic (including light and heavy duty vehicles, natural gas buses, and biodiesel vehicles), harbor and airport operations, power plants, and photochemically induced atmospheric reactions. We focus our work on particulate matter (PM) and its gaseous precursors in the atmosphere. Through our research efforts, we seek to understand how toxic mechanisms and resulting health effects attributable to these air pollutants vary with their source, chemical composition and physical characteristics.
Our work has been motivated by the emerging scientific literature liking mortality and morbidity to exposure to PM. The majority of our efforts are funded by the US EPA through the Southern California Particle Center (SCPC). Additional funding comes from the National Institutes of Health (NIH), the California Air Resources Board (CARB) and the South Coast Air Quality Management District (AQMD). The overall objective of the Southern California Particle Center (SCPC) is to bring together outstanding scientists to conduct high priority research to elucidate the underlying basis for health effects associated with exposure to ambient particulate matter (PM) and its relation to its sources. With a total funding exceeding $40 million so far, this has been one of the largest consortia in the US history to investigate sources, exposure assessment and health effects of air pollutants.
Our major research themes and hypotheses include:
· Investigation of the physical and chemical properties of pollutants emitted from different sources (traffic, power plants, airports, harbors, atmospheric reactions).
· Evaluation of how population exposure to these pollutants and the toxicity from these sources vary with respect to location and season
· Assessment of relative toxicity of pollution sources using as realistic atmospheres and exposure levels as possible, using technologies developed by our group at USC.
· Investigations of the chemical and toxicological properties of PM and co pollutants emitted from newer vehicles that are designed to meet the 2007 emission standards of the state of California. These vehicles include low sulfur diesel equipped with catalytic filters, biodiesel, compressed natural gas buses, and gasoline vehicles.
· Assessment of the contributions of the main outdoor pollution sources to indoor air exposure and toxicity.
· Determination of how pollutants emitted from various sources are distributed within communities and what are the implications for human exposure.
Our most important accomplishments at the USC Aerosol Lab to-date include:
· The most extensive physical and chemical characterization of air pollutants intensive monitoring studies in the Los Angeles Basin (LAB) ever conducted.
· Development of continuous monitors for measurement of particle mass, size and chemical composition
· Development of mobile, size-selective PM concentrators capable of collecting large amounts of ambient samples for in vitro, in vivo and human clinical studies.
· Characterization of the formation and dynamics of air pollutants near freeways and demonstration of increased (~10-fold) exposures to these toxic pollutants in the vicinity of freeways and busy thoroughfares.
· Demonstration of cellular damage by inhalation of PM through mitochondrial uptake of ultrafine (nano) particles.
· Demonstration that pro-oxidative PM chemicals induce oxidative stress effects which leads to cardiovascular health effects.
· Demonstration of allergic airway responses, neurological and cardiovascular effects in humans in close proximity to a freeway.
· Demonstration of a linkage between traffic density and human developmental toxicity.
· Publication of over 300 refereed journal articles, describing the above studies and their findings, cited over 14,000 times to-date.
· Funding of about $22M secured through end of 2020 (approximate funding at $800-900 K/yr).
· Citations: ~14,000 according to the ISI Web of Science
· 13 US Patents
· Mentoring of 22 Post docs.
· Mentoring of 23 PhD students.
· Multi- disciplinary research, in concert with school’s vision on urban sustainability and other thrust areas such as the nano-bio field.
· Use of our findings in legislation, including:
o Revision of US EPA National Air Quality Standards (NAAQS) on PM.
o Use by state of California in promulgating the Senate Bill 25 (Protection of Children’s heath).
· 2011 Haagen-Smit Award/Prize recognizing our outstanding paper published in Atmospheric Environment (Y. F. Zhu, W. C. Hinds, S. Kim, S. Shen and C. Sioutas. Study of ultrafine particles near a major highway with heavy-duty diesel traffic. Atmos. Environ., 36, 4323-4335, 2002).
· 2014 David Sinclair Award by the American Association Aerosol Research