The Environmental Chemical Sciences (ECS) program of the Division of Chemistry will support the research program of Associate Prof. Anne Johansen of Central Washington University (CWU). Dr. Johansen and her research group will study the chemical mechanisms linking physico-chemical properties of collected atmospheric ultrafine particles (¡Ü 100 nm, UFP) to their environmental reactivity and physiological toxicity. Two main particle characteristics are investigated: (i) the content of redox-active, or bioavailable iron, and (ii) the degree of particle surface carbon oxidation. In addition, the presence of potential electron donors in the surrounding matrix will be evaluated. By using model soot and real UFPs, mechanisms will be identified and their relative significance assessed in biologically and environmentally relevant conditions. Research will be conducted at CWU and the Pacific Northwest National Laboratory User Facility (EMSL) with the aid of custom-made and state-of-the-art instruments. These analytical capabilities will enable the generation of novel results that are likely to increase current understanding of the reactivity and transformation of carbonaceous particles in a variety of settings. An important educational component of this study is the effective training of undergraduate students from a primarily undergraduate institution located in a rural setting such as CWU. A large number of underrepresented minority students will gain experimental, critical thinking and communication skills through their hands-on work while collaborating with scientists from the nearby National Laboratory.