This project is a continuation of highly successful work by this investigator on the chemical composition of ambient dust particles by consideration of two toxicologically important radionuclides, Plutonium (Pu) and Americium (Am), relatively long-lived species primarily resulting from nuclear weapons testing fallout. Little is currently known regarding atmospheric transport and eventual fates of these particular radionuclides, and their contribution to radioactive contamination of ambient airborne aerosols. This study will quantify Pu and Am activity in atmospheric soil aerosols measured at sites where dust from major source regions in Asia or Africa can be sampled. These data will be compared with historical U.S. data to identify similarities and/or differences in radionuclide contamination. This research will provide an improved understanding of biogeochemical cycling of dust and radionuclides in the ambient global atmosphere, and potentially have important implications for homeland security with respect to release of radioactive materials to the atmosphere. Other broader impacts of this project include collaborations with a number of domestic and international institutions, which will facilitate technology transfer and considerable value-added science. A full-time graduate student and a number of undergraduate assistants will be involved in the project providing valuable research experience and professional development opportunities to these young scientists. The project also includes a variety of scientific and community outreach activities, including the development of web-based educational materials.
