HR: 16:15h
AN: A54A-02    [Abstracts]
TI: Lead in single atmospheric particles
AU: * Murphy, D M
EM: Daniel.M.Murphy@noaa.gov
AF: NOAA Earth System Research Laboratory, 325 Broadway, Boulder, CO 80305, United States
AU: Hudson, P K
EM: phudson@fullerton.edu
AF: California State Fullerton, 800 N. State College Blvd., Fullerton, CA 92834, United States
AB: Single particle measurements using PALMS have shown that a significant fraction of accumulation mode particles contain trace amounts of Pb. This talk will explore the reasons for the frequency of Pb in fine particles now that most gasoline is unleaded. Trace amounts of Pb were found in 5 to 25 percent of 250 to 3000 nm diameter particles sampled by both aircraft and surface instruments in the eastern and western United States. Lead was found on all types of particles, including Pb present on biomass burning particles from remote fires. Less common particles with high Pb contents contributed a majority of the total amount of Pb. Single particles with high Pb content often also contained alkali metals, Zn, Cu, Sn, As, and Sb. The association of Pb with Zn and other metals is also found in IMPROVE network filter data from surface sites. Sources of airborne Pb in the United States are reviewed for consistency with these data. The frequent appearance of trace Pb is consistent with widespread emissions of fine Pb particles from combustion sources followed by coagulation with larger particles during long-range transport. Clean regions of the western United States show some transport of Pb from Asia but most Pb over the United States comes from North American sources.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting