Dr. John G. Watsons research includes: 1) evaluating, characterizing, and advancing methods to measure carbonaceous material in suspended particles; 2) developing and applying real-world, multipollutant emission measurement technologies; and 3) designing and conducting aerosol characterization, source apportionment, and adverse effects studies. His recent projects involved real-world emissions testing in the oil sands region of northern Canada, engine exhaust characterization in Hong Kong, commercialization of a multi-wavelength thermal/optical aerosol carbon analyzer, and designing air quality measurement networks in developing countries. Current projects include evaluation of microsensor/smartphone interfaces for detecting intermittent fugitive emission, increasing the efficiency and cost-effectiveness of particulate matter and visibility measurement systems, determining changes in aerosol chemical and optical properties with atmospheric aging, and quantifying atmospheric contributions to stormwater runoff.. These projects involve supervision and mentoring of graduate students and post-doctoral fellows.