Under this project Dr. Haofei Yu is developing a smart, connected, low-cost, portable and easy-to-use measurement system that can be attached to buses to measure the spatial concentration distributions of fine particulate matter (PM2.5) air pollution. PM2.5 is the most harmful air pollutant in the US and worldwide, and its concentrations are known to vary drastically spatially. Better understanding and characterizing its spatial concentration distribution is important for designing effective management strategies to mitigate the harmful health and environmental impacts of PM2.5.