Abstract
   The chemistry of copper (Cu) in atmospheric aerosols is complex, constrained partially by corrosive weathering nuanced by local aerosol chemistry and overtly controlled by source factors which influence the chemical speciation of Cu in emissions. Largely resulting from automotive brake wear Cu is notably enriched in fine and ultra-fine particulate matter (PM2.5 and PM0.25), especially in urban locations where PM is considered the greatest environmental hazard to human health. Inadequate and often simplified characterization of Cu in ambient PM and automotive brake wear prevents full realization of this hazard and handicaps modelling and remediation efforts. Herein we utilized X-ray absorption spectroscopy (XAS) to investigate the chemical speciation of Cu in several systems including urban ambient PM, brake wear particulate, and weathered/aged brake wear. The coupled nature of these experiments illustrated the causal links between automotive brake wear and urban ambient PM further elucidating the major Cu species relevant for environmental and human health concern. 
   

Biography
   Paul J. Aronstein is a PhD Candidate in the Environmental Systems graduate program at UC Merced. He received his Bachelors of Science in Chemistry from The Evergreen State College. Since joining UC Merced Paul has been fascinated by the complex chemistry of metals in the environment with a focus on heterogenous systems.