Measuring natural radioactivity in aerosols: Lead-210 and beryllium-7 as tracers for aerosol washout

CHED 1105

Michael J. Tackett, mjtackett@ualr.edu1, Gunawan Gunawan1, Nancy A. Marley, namarley@ualr.edu2, and Jeffrey S. Gaffney, jsgaffney@ualr.edu1. (1) Department of Chemistry, University of Arkansas at Little Rock, Little Rock, AR 72204, (2) Graduate Research Institute, University of Arkansas at Little Rock, SCLB Rm. 456, 2801 S. University Ave., Little Rock, AR 72204
Atmospheric aerosols are important in climate and air quality considerations. Their impacts depend on their chemical and physical properties and their residence times in the atmosphere. Accumulation mode aerosols (0.1-1.0 micron size range) are likely to have the longest atmospheric residence times with water uptake and washout or gravitational settling (dry-deposition) dominating their removal. Discussed will be measurements of 210-Pb and its daughters (210-Bi and 210-Po) as well as 7-Be as atmospheric aerosol tracers. Laboratory experiments looking at the effects of “washing” of aerosol samples collected at a number of different urban sites are described that address the strength of the radionuclide tracer association with carbonaceous aerosols. Experiments using dry and wet sampling methods are also described that indicate carbonaceous aerosols are not rapidly removed from the troposphere. This research was supported by the Office of Science (BER), U.S. Dept. of Energy, Atmospheric Science Program under Grant No. DE-FG02-07ER64328.
 

Undergraduate Research Poster Session: Environmental Chemistry
2:00 PM-4:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster

Division of Chemical Education

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008