Special Symposia
Tuesday, October 21
“Frontiers in Megacity Aerosol Research”
Conveners: L.C. Marr and M. Bergin
The rapid proliferation of megacities and their air quality problems are producing unprecedented air pollution health risks and management challenges. Emissions from megacities affect not only local populations but also regional and global scale atmospheric chemistry and climate. Presently there are 20 megacities with populations in excess of 10 million, and the number is expected to increase to 26 by the year 2015. The extremely high aerosol loadings in megacities make them unique laboratories for studying the complex physical and chemical processes that form and transform particles. In addition, megacities offer special opportunities to study particulate impacts on human and environmental health due to the relatively large signals (e.g. relative health risk, regional radiative forcing) associated with the high particulate concentrations. This special symposium will center on (1) exposure, risk assessment, and policy implications, (2) aerosol measurements, and (3) regional and global impacts.
Wednesday, October 22
“Applications of the Electrospray”
Convener: W. Deng
Electrospray is an elegant technique to generate aerosols with monodispersed droplets/particles from a few nanometers to hundreds of micrometers. This booming area has made significant impact to nanotechnology and biotechnology, evidenced by John Fenn's 2002 Nobel Chemistry Prize for electrospray-related work. Given recent progresses on coaxial and multiplexed electrospray, the aerosol research community has a pressing need to draw together the multidisciplinary researchers to communicate on the potential applications of the electrospray. This special symposium strives to bridge the gap between electrospray researchers and general aerosol scientists who seek an aerosol generation technique with excellent monodispersity, complex structures, and/or high throughput.
Thursday, October 23
“Particulate Matter and Mobile Sources”
Conveners: A. Ayala, A. Vette, J. Herner
Mobile source emissions of particulate matter (PM) and its precursors impact air quality and human health across multiple temporal and spatial scales. Approaches to characterize emissions include the use of dynamometers to simulate driving conditions for individual vehicles, remote sensing technologies under actual driving conditions, and field measurements to estimate integrated roadway emission factors. Once emitted to the atmosphere, the complex mixture of condensed and gaseous species undergo rapid dilution and cooling, resulting in high numbers of ultrafine particles adjacent to roadways. These ultrafine particles rapidly coagulate into the accumulation mode or evaporate such that particle counts return to background levels over relatively small distances. Also, coarse particles are generated by mechanical abrasion, and vehicle induced turbulence can resuspend road dust. Recent investigations of near- and on-road particle concentrations have sparked a great deal of interest in primary emissions from on-road vehicles and also in the "plume processing" that occurs under real-world conditions. As mobile source emissions are transported away from roadways, dilution and interaction with ambient pollutants may change the physical, chemical, and toxicological nature of the emitted aerosols. Attributing pollutant impacts to underlying causes underscores the need to differentiate the contribution and toxicity of aerosols from various emission sources at the urban scale. Health studies implicate PM from various sources, including vehicles, in adversely affecting human health at the urban scale.