Detrimental effects of carbonaceous nanoparticles (CNP) emitted from fuel combustion are well-known, but their underlying chemical mechanisms are ill-defined. It is generally thought that associated particle toxicity and reactivity stems from the in vivo production of reactive oxygen species (ROS), however, the details remain tenuous. In the present project, we seek to further our understanding of certain particle characteristics that have been suggested as potential culprits for the generation of ROS, namely trace metals and aromatic hydrocarbons. Specifically, we will test cell function and viability, in relation to particles (i) bioavailable iron content, (ii) quinone-like molecules and surface functionalities, and (iii) inherent structure of the carbonaceous component of the soot. This targeted focus emerges as a result of published works from a previous collaborative project between our laboratory and EMSL, indicating that both Fe(II) and anthraquinone (AQ) may be key players in particle toxicity when exposed to mitochondria. We propose using real and model soot particles to perform cellular viability studies (with Dr. Galya Orr at EMSL), while characterizing the same particles with a range of instruments available at EMSL and CWU: surface functional groups (XPS at EMSL), polycyclic aromatic hydrocarbons (PAHs) and related quinones (GCMS at EMSL), carbonaceous structure (Raman Spectroscopy at EMSL), bioavailable iron (CWU) and generation of ROS (CWU). This is a rapid access proposal to complete experiments and analyses at EMSL over a short <30-day period, early in the upcoming summer 2014. The primary reason for this avenue of submission is that results are time sensitive, as they are needed to complete two M.S. student and one undergraduate Science Honors theses for defense and dissemination in early fall 2014. Central Washington University (CWU) students intend to visit EMSL in July 2014 to perform experiments and analyze samples. Funding for this work is secured through a current NSF grant and the CWU Science Honors program. The combination of expertise and multifaceted capabilities available at EMSL is unique and essential in drawing the comprehensive picture necessary to provide us with new insight into the fundamental processes that CNPs undergo in biological and environmental systems.