I became interested in the characterization of urban air quality after working in Beijing in the mid-1990s. I make measurements to model the spatial and temporal distribution of pollutants. I am particularly interested in bringing new methods and technologies into exposure assessment for air pollution health studies. In particular, I would like to increase the use of optical remote sensing and mobile monitoring approaches in air quality monitoring. I am also interested in developing appropriate air pollution monitoring approaches for cook stove intervention studies and integrated assessment of climate change impacts in "southern" countries.