My general research focus is on the influence of air pollution on both climate and human health. My specific interest is particulate matter (PM), and I have done a wide range of studies on the emission, formation, deposition and impacts of PM. I am particularly interested in how PM impacts climate by modifying the radiation balance of the atmosphere and I have done studies in both pristine regions of the world (Greenland and the Himalaya), as well as hazy regions (the Southeastern US, China, and India). More recently I have been studying the influence of PM on human health with emphasis on determining the relative contributions of sources (such as biomass burning and vehicular emissions) to acute health impacts. I am also involved in developing and deploying the next generatio n of air quality sensors to inform citizens on the quality of the air they are breathing so that they can make informed decisions to improve their air. My vision involves combining a multidisciplinary, multicultural approach to research and education that brings together researchers from around the world to collectively work together to make the air cleaner.